INTRODUCTION

 The city of  Davao has a land area of 244,000 hectares.  Being one of the largest cities, if not the largest in the world, Davao City is home to roughly one and half million residents.  Aside from its inhabitants, the city also hosts a large number of industries and commercial establishments.  By reason of its size, diverse elements and the rapid development of the area, environmental consequences brought about by these factors are not going to be unexpected or unforeseen.  Daily, we see thousands of motorists and vehicles on the major thoroughfares.  Factories, assembly plants, and manufacturing establishments abound in the industrial centers of the city.  These motor vehicles and factories emit fumes and discharge wastes out into its surrounding areas.  The effects of these fumes, smoke and other emissions are not only felt and seen within the immediate vicinity of the industrial  areas and the streets of the city.  In time, their consequences will be manifested in the ecosystem of the urban areas.  More importantly, it shall be evident in one of the most important aspects of our environment, which is air.

 Air is an indispensable factor of human existence.  Without air, life cannot be sustained.  People strive not only for existence and survival, but also for development and growth.  In the process of realizing these aspirations, certain elements in our environment are dealt with by man.  These elements are used, exploited, compromised and eventually sacrificed by man.  The air, more specifically its quality, is one of them.

 This study will focus not merely on the present state of air quality in urban areas such as Davao City.  Numerous studies have been devoted to determining that air quality has deteriorated to such levels that are already intolerable for human consumption.  Our study will be devoted to one of such means with which air quality can be improved and sustained in our City.  These are trees.  The role of trees in the environment is of such great importance.  They absorb carbon dioxide and emit oxygen.  They provide shade and help strengthen our soils, among others.  This is the reason that parks and other green areas in our cities are established and must be maintained and further developed.

 This study will focus on the role of parks, green areas and greenbelts in our environment.  The trees in these places help in having clean and breathable air in our environment.  The existing parks and green spaces being maintained by the city government will be one of the focal points of the study.  Each will be analyzed and evaluated in terms of how the area was utilized in order to have a place that not only provides a place of leisure for people but also how it was built for the purpose of contributing to air quality.  Furthermore, areas that are potential parks, green spaces and greenbelts will also be included in the study.  Considering the land area of the City, there should be an appropriate number of such places in various parts of the city.

 Other elements of the study will be determining the tree species that are appropriate for this purpose and other plants that can also be used.  Human intervention, in terms of its actual use and the manner by which it is built are also important considerations that will be part of the study.

 More importantly, pertinent laws, rules and regulations issued by the Congress, the Local Government Units and administrative agencies are also included since these form the backbone of implementing these matters.  The present organizational structure of government agencies and offices concerned will also be presented and explained.

 Lastly, recommendations and suggestions to the proper government authorities will be taken up in order that certain aspects in establishment and sustainability of these areas will be improved. 
 

METHODOLOGY OF STUDY

The case study method will be used for each specific park, public open space and other vacant government lands, which are potential greenbelts and green space.  Our study will analyze and assess these public parks and spaces based on how the area was utilized for the purpose of public use and benefit.  Three basic factors were considered for assessment of each specific area.  These are: (1) Use, (2) Allocation, and (3) Access.  Furthermore, the matter of human intervention in terms of alternative use, abuse and other forms of activity will also be an important consideration. 

To facilitate the study, ocular inspections were held on each area.  Interviews with officials of concerned government agencies and offices were also made.  Material from these agencies and offices, as well as plans and proposals made for other areas outside of Davao City were also studied to determine their suitability to the local area.

Recommendations, which will be based on our research findings, interviews and on-site inspections will also be discussed.
 

RELEVANT STATUTES AND ORDINANCES

 In support of Presidential Decree (PD) No. 953,  “Requiring the Planting of Trees in Certain Places and Penalizing Unauthorized Cutting, Destruction, Damaging and Injury of Certain Plants and Vegetation”, the Board has passed Resolution No. 532 series of 1993 which approves the rules and regulations to implement PD 953.  Relative to this the HLURB issued this administrative order identifying the suitable tree species and the manner of planting these in designated areas of subdivision to prevent damage to underground utility lines and overhead power transmission lines.

 As provided under Section 2 of P.D. 953 (1976) every owner of land subdivided into residential / commercial / industrial lots after the effectivity of this decree shall reserve, develop and maintain not less than thirty percent (30%) of the total use of the subdivision, exclusive of roads, service streets and alleys, as open space for parks and recreational areas.  No plan for a subdivision shall be approved by the Land Registration Commission or any office or agency of the government unless such requirement is complied with and furthermore, the owner thereof undertake to develop such open space within 3 years from the approval of the subdivision plan, in accordance with the development plan approved by the Bureau of Forest Development and to maintain such parks and recreation areas.

 However, with the passage of P.D. 1216 (1977), the thirty percent (30%) required open space can be reduced to a level that will make the subdivision industry viable and the price of residential lots  within the means of the low income group and at the same time preserve the environmental and ecological balance through rational control of land use and proper design of space and facilities

In accordance with P.D. 953 and 957 as amended by P.D.1216 and as further amended by HB 13376 the following should be required :

A. Developer / owner of industrial estate and commercial complexes must provide within the land an area of 1 hectare or more as defined within the boundary, a plot ratio of 70% for development and 30% as green area.  This green area is an open space that should be exclusively devoted for parks, playground  and recreational use.  This means that amenities such as swimming pools, tennis courts, playgrounds, sandpits, pavilions, fountains, etc. may be included within the 30% green area.

Excluded in the 30% green area are car parks, road reserves, drain reserve, bin centers, septic tanks, electric substations and planters and planting area within the buildings.

All green area must be turfed or landscaped.

B. In the case of residential subdivision development with one or more hectares shall likewise reserve 30% of the gross area for open space allocated exclusively for parks, playgrounds and recreational use.
Specifically, tree-growing site in these open spaces shall cover the following :

- Nine (9) percent of gross area for high density or social housing (i.e. 66-100 family lots per gross hectares).
- Seven (7) percent of gross area for medium density or economic housing (21-65 family lots per gross hectares).
- Three (3) and a half (3 1/2) percent of the gross area for low density or open market housing (10-20 family lots and below per gross hectares).
Developer / owner is encouraged to provide for as much area and planting strips as possible to make living more environmentally wholesome. 

 Location of Electric Poles
1. All proposed poles shall be 10.6 meters (35ft)
2.  All proposed poles shall be installed 15 cms. From the gutter of the road.

**Proposed Amendment Filed in Congress Through House Bill No. 13376 (known as the "Greening Act of 1994")
 

EXISTING PARKS AND PUBLIC OPEN SPACES IN DAVAO CITY

The city government of Davao maintains fifteen (15) parks, six (6) landmarks and one hundred forty eight center-eight (148) center islands throughout the City.  The maintenance of these areas is through the office of the City Environment and Natural Resources Office, or the City ENRO.  A number of these parks and public open spaces is also the object of joint efforts of the City ENRO with various socio-civic groups, private commercial corporations and other non-government organizations.  The lead organization for non-government participation in the maintenance and beautification of these sites is the Davao Beautiful Foundation (DBF).  The DBF serves as the conduit for the participation of the private sector in the greening and beautification of the city.  It also initiates projects for this purpose.  The DBF works in coordination with the City ENRO for projects of the city government.

I Public Parks

1. Rizal Park    5. Millenium Park 
2. Magsaysay Park   6. Clifford Park
3. Osmeña Park    7. Centennial Park
4. Quezon Park 
 

II Greenspaces & Greenbelt

 1. Buhangin Flyover Greenery
2. Dacudao Avenue greenbelt
 

These parks and landmarks are created by virtue of relevant ordinances and resolutions passed by the local legislative council, which is the Sangguniang Panglunsud..
 

CASE STUDY AND FINDINGS

I PUBLIC PARKS

1. RIZAL PARK
This park is the civic space of the city.  It is basically a plaza where people converge for various activities.  The park comprises 3,661 square meters on a square lot.  The whole area's surface is in concrete except for around six (6) plant/tree boxes measuring 3 x 3 meters.  Some of them are planted with grown trees while the rest are devoted to ornamental plants only.

2. OSMEÑA PARK
Osmeña Park is adjacent to the building that houses the Sangguniang Panglunsod.  A circular monument is in the middle of the park with pathways radiating from such central point extending to the edge of the lot leading to the sidewalk of the road.  The area is planted to a good number of trees, particularly acacia mahogany and talisay. Palm trees are also found around the monument. A concrete sidewalk is built on the portion spanning Magallanes Street.

3. CENTENNIAL PARK
The Centennial Park was established to commemorate the centennial celebration of Philippine Independence.  A monument with statues is in the middle of the park.  A one-meter wide concrete pathway traverses the length of the park, cutting across the said monument.  Full-grown acacia mangium, talisay and palm trees are planted.  Other species of trees are also found. Benches are also placed around the monument.

4. MILLENIUM PARK
This park is the latest to be established by the city government.  Rectangular in shape, it also serves as the center island of Roxas Avenue.  It has fully concreted sidewalks on both lengths, measuring approximately one meter each. A fully concreted two-meter wide central pathway and two concrete structures (fountain and gazebo) are also be found therein.  Palm trees, bouganvillas, talisay trees and other ornamental plants are planted.  On its northern end, which faces Claro M. Recto Avenue, eight circular plant boxes are planted to talisay trees.

5. CLIFFORD PARK
This park comprises one thousand four hundred square meters in area, more or less.  It is located along Roxas Avenue, straddling Claro M. Recto Avenue and Bangoy Street.  The park also serves as the center island of Roxas Avenue.  A one-meter wide concrete sidewalk surrounds the park and a concrete central pathway cuts across the length of the area.  One half (1/2) of the park is planted to full-grown talisay and  trees.  On the other hand, the other half is planted to calachuchi trees.  There are also eight (8) plant boxes planted with bougainvillas. 

6. MAGSAYSAY PARK
The park is also a plaza and civic space for public gatherings.  A wide concrete path leads to the monument.  Medium and large-sized acacia and talisay trees are planted but there are more small trees and shrubs. 

7. QUEZON PARK
Quezon Park is located in front of the Davao City Hall.  Full-grown acacia trees can be found therein.  There are also two (2) fountain areas that take up a major part of the park.  A central pathway is between the fountain areas provide access to the City Hall, as well as to and from the park. 
 

II  EXISTING GREENBELTS AND GREENSPACES

1. BUHANGIN FLYOVER GREENERY
The garden around and beneath the flyover covers an area of eight hundred square meters, more or less.  This is a project of the Davao Beautiful Foundation and the Land Bank of the Philippines.  Palms, mall trees, ornamental and garden plants can be found in the site. The trees and plants are concentrated in one area near the base of the flyover.  The rest of the site is planted with carabao grass and low hedges especially along the shoulder of the road.
 
 

2. DACUDAO AVENUE GREENBELT
The greening of Dacudao Avenue is under the jurisdiction of the City ENRO.  Gmelina and Neem trees are planted along both sides of the center canal.  The length of the greenbelt stretches from the Buhangin flyover up to Obrero.
 

ASSESSMENT AND CRITICISM OF EXISTING PARKS AND GREENBELTS

  These findings and assessment are the result of our ocular inspections, interviews with officials of concerned government offices and are also based on relevant data from the same offices.  These are meant to aid and assist the Clean and Green Program of the city government in re-designing and improving these areas so that they can be the ideal greenspaces for the city.  Making them into such greenspaces will not necessarily transform them for this purpose only.  The goal of this study is to convert these and future parks and open spaces into dual-purpose sites.  They provide the public with places of leisure and relaxation.  At the same time, concern for the environment and for the people's well-being is also addressed by these new green areas.

I
1. Rizal Park 

There is limited space available for trees and plants in the park.  This is due to the nature and use of the park as civic space for the public.  The use of the existing tree and plant boxes will have to be maximized. There are plant boxes at one side of the park where trees and garden plants are being maintained.  On the plaza itself, there are provisions for trees available.  Some of these provisions (tree boxes) are planted with medium and large-sized trees.  However, the others are planted with smaller trees and ornamental plants only.  Trees, similar to those already in the other boxes should be planted there as well.  Smaller garden and ornamental plants can also be planted to complement the trees.  Large trees are suitable for this site since it is an open space with no restrictions as to the height and crown of the trees.

2. Clifford Park

The half portion of the park planted to calachuchi should instead be planted with medium to large sized trees.  This is to complement the other half that already has full-grown trees.  The site should be planted to only one species of trees.  This is create a visually smooth and uniform appearance of the greenspace.  The choice on what particular trees to be planted should be taken from the list of recommended species for such parks so that it will be a veritable greenspace.  The center pathway should be redesigned in a way that it will contribute to the greening and not merely to provide access within the site.  It is recommended that perforated slabs of bricks or concrete should be used instead so that the pathway will also serve as an extension of the greenspace.  These perforated slabs provide aeration for the soil beneath the pathway and also for the growing trees.  Grass and smaller garden plants can still be planted in the space between the slabs.  This is not possible with a 100% hard concrete surface.
 
 The vendors who are using the center pathways for their own  purpose should be relocated by the city government to other places and be prohibited from using the site as a place to conduct their business.  They alter the use of the park and also contribute to the litter on the place.

3. Millenium Park

Access to and from the park is sufficient because concrete sidewalks were built around the perimeter of the park.  The center pathway should be redesigned in the same manner as that of Clifford Park.  The 100% hard concrete surface should be replaced with the aeration and perforated slabs.  They retain some greenery and help hasten the air and water absorption of the soil because the slabs do not cover the soil surface entirely.  Furthermore, this center pathway takes up so much of the space in the park because of its width.  As a result, people are relegated to the two narrow stretches on both sides where the plants and benches compete for space.  It should be reduced by one meter so that additional soil surface can be devoted to the proposed greenspace.

Eight small talisay trees are planted in the circular plant boxes located at the northern edge of the park.  Aside from them, not a single tree is planted in the park.  Only bougainvillas and palm trees are planted along the length of the park. Large-sized trees should be planted especially on the side facing Ateneo.  This will complement the existing acacia trees on the side of the school.  On the side facing Aldevinco, medium trees should be planted because electrical lines pass through that side.  They will also complement the trees planted along the planting strip provided along the opposite sidewalk.

Light posts are located along the same length as that of the palm trees and bougainvillas.  These posts are so many that they are located so close to each other. It is suggested that such number of these posts should be removed in order that proper distance between them can be observed.  This is taking into account the trees that will be planted alongside them.

4. Osmeña Park

The park has a large number of full-grown trees.  However, there are other species of trees that are also growing there.  It recommended that the tree species to be planted in the future should be limited to a maximum of three (3) only.  The species of the full-grown trees should be followed in making choices for this park.  The concrete pathways should be maintained as they are since pedestrian traffic in the area is high due its location near the government center of the city.  Benches are provided along the pathways that lead to and from the monument at the center of the park.  However, there are (1) vendors (2)  chess players.  A definite area should be appropriated for these players.  Vendors should be relocated to another place away from the park.

5. Magsaysay Park 

The park has wide concrete walkways wide enough to accommodate motor vehicles.  The trees and plants planted in the park should be of much bigger sizes than those presently being maintained therein.  The park has a large land area and is an open space at the same time due to its plaza-like nature.  Large-sized trees should be planted instead of talisay.  Trees like acacia, palawan cherry are suitable because they have wide crowns that provide shade.  However, only one or two species should be used to maintain an attractive and smooth greenspace.

6. Centennial Park

The existing trees on the park should be of the same species only.  In the case of this park, several have been planted and maintained therein. Furthermore, they are of varying sizes and heights.  A single species of trees will create an attractive and harmonious appearance for the park.  It avoids a visually confusing form of greenspace for the site.  More importantly, tree size should be carefully chosen so that they will not overwhelm the monument, which is located in the center.  The pathway should be maintained as it is since the pedestrian traffic in that area is high.  The Sangguniang Panglunsod is located behind the park and a large number of people pass through daily.

7. Quezon Park 

The park has limited space for greenspace because two (2) fountain areas are built alongside each other.  A central path cuts across the 2 fountain areas, providing access to and from San Pedro Street and City Hall Drive.  Large-sized acacia trees are planted at vantagepoints throughout the site, speficially alongside the fountain area and along the adjacent street.   There is still enough  space though, between the existing trees.  Additional trees should be planted at those available spaces.

Benches along the pathway and near the flagpole provide rest areas for the public.

II

1. Buhangin Flyover Greenery

The area around and beneath the Buhangin flyover is a veritable greenspace.  Small trees and garden plants are planted but a substantial land area is still unutilized for the purpose of establishing greenspace.  The area is triangular in size such that a major portion is not beneath but adjacent to the structure.  Medium sized trees can be planted in the middle of the site.  For portions of the site near and under the flyover, shrubs hedges and garden plants should be used to soften the visual impact of the structure.  Large-sized trees are not advisable since it is a high-traffic area where accidents can be caused by falling trees or branches.  Only one species should be used so that trees will blend well with all the other smaller plants.
 

2. Dacudao Avenue Greenbelt

This avenue is the only greenbelt so far in the city poblacion.  This site is under the jurisdiction of the City ENRO.  The site is being maintained and further developed by said office.  However, gmelina and neem trees are not advisable for greenbelts.  These species have a relatively short lifespan and are not of a durable variety.  Another species should be planted along this belt.  This will complement the greenspace at the Buhangin flyover at the edge of Dacudao Avenue.
 

PROPOSED AREAS FOR  GREENSPACE, AND GREENBELTS

These are the specific areas that have been determined by our study as potential sites for the purpose of establishing these parks, greenspaces and greenbelts.  They are projected to complement the existing areas being maintained by the city government.  Thus, it is proposed that they be utilized as a new pilot group subsequent to those presently being maintained and developed.  This list does not, in any case, preclude the inclusion of other sites that may be later found to be suitable for the purpose if ever they will be eventually considered by the city government.  This proposed pilot group may serve as the model for future development of new sites in accordance with similarly proposed guidelines and requirements.
 

I Vacant Government Lands
1. the former Davao City Sports Center complex

II Unutilized traffic islands

1. Big road island at the intersection of Quirino Avenue, Bangoy and Jacinto Street
2. road islands along San Pedro Street, in front of the City Hall

III National Roads and City Roads
1. Quimpo Boulevard
2. Roxas Avenue
3. Quezon Boulevard
4. Candelaria Street, Ecoland Subdivision Phase 2
5. Ecoland Drive, Ecoland Subdivision Phase 4

I
Former Davao City Sports Center complex
 This property is ideal for the purpose of our study by reason of its area and strategic location in the poblacion area.  The property has a land area of 72,220 square meters or 7.22 hectares.  It is located at the corner of Palma Gil and Camus streets, beside two public elementary schools.  However, there is a pending lawsuit between the city government and the donors of said property.  In the event that the case is decided in favor of the city, this site is by far the most ideal site. 
 
The existing greenery of two (2) adjacent public elementary schools will complement this park, upon development.

II 

"The Venue/Club Med" road island 

 This road island is one of the biggest in the city, measuring 275 square meters more or less.  It is an ideal site for greenspace since it is located at the intersection of three major roads in the poblacion area.  A number of small trees are already planted.  More trees should be planted there if this site will be developed as greenspace.  However, only small trees can be planted since many electric and utility posts are located on the island.  Wires and other electrical connections crowd out the trees.  These posts can be relocated to another place nearby if the site is to be developed as greenspace. 

Ample pathways should be provided for access, taking into consideration the three major roads where pedestrian traffic will come from.  The site should also be landscaped and its soil surface rehabilitated because it has been subjected to pedestrian damage for a long period of time.

Road islands along San Pedro Street fronting the City Hall

These road islands have a width of two and a half meters, which is twice the size of that of regular road islands in the city.  These particular islands must be fully utilized because of its central location and proximity to the Quezon, Centennial and Osmeña parks.  It has two (2) concrete waiting sheds.  However, the rest of the islands have been fully cemented.  As a result, the few garden plants therein are confined to a few plant boxes.  In this site, medium to large-sized trees can be planted.  Maintaining one-meter wide concrete paths at certain points can provide pedestrian access.  The rest of the site should be devoted to the proposed trees, as well as garden plants and grass.

These islands are not burdened by any obstruction over it.  Thus, large-sized trees with wide crowns can be planted.  It will complement the large trees at the Quezon and Rizal parks. 

III

The proposed greenbelts can be established along the city and national roads included in this pilot group.  Greenbelts, as defined, are "the roads and their corresponding planting strips and islands that connect the urban and the rural". In the case of Davao City, these belts should be planted in city roads and national roads within the territorial jurisdiction of the city since Davao is still made up of both urban and rural areas.  These national roads connect them with each other. Per materials gathered from the regional office of the Department of Public Works and Highways (DPWH), its maintenance department has already commenced tree planting along three (3) national roads.  They are the Davao-Bukidnon highway, Davao-Cotabato highway and the Inawayan-Baracatan highway.  For this reason, these city and national roads are the proposed greenbelts in the pilot group.

1. Quimpo Boulevard

This national road starts from a point along McArthur Highway in Matina going to Doña Luisa and Ecoland subdivisions.  It crosses the Bolton bridge and ends at the intersection of Quezon Boulevard and San Pedro Street.  Except for that portion of the road passing through Ecoland and Juna subdivisions, development of properties along the road is not yet fully implemented.  More importantly, the road widening is already completed.  Thus, the establishment of the greenbelt on its road-right-of-way can be done without any problems as to the adjacent private property.  The DPWH has prescribed technical plans and guidelines for the purpose of planting trees and greenery along these national roads.  Neem trees are already planted along the side of the road.  Neem trees are not among those species that this study is recommending for the proposed belts.  Any of those recommended trees should replace them.

Quimpo Boulevard connects with Quezon Boulevard at the intersection with San Pedro Street.  If the two roads are to be developed as greenbelts, one long continuous belt will be realized through this study.
 

2. Quezon Boulevard

Quezon Boulevard is another ideal site for a greenbelt.  The road infrastructure is already fully developed.  The road right of way for sidewalks and the planting strip is already in place.  Actual planting and maintenance can be commenced on the area at any time.  The electric and light posts are located on the center island.  Thus, there will be no problems on overhanging wires and other utilities that will have to be considered.  There are already existing trees and plants planted on the strip at some points along the road.  The future development of the greenbelt would have to integrate these already existing trees and plants. The belt should also be landscaped in order that its appearance will be enhanced.  Choice of species may be taken from these trees if they are among those recommended. 

This road is also perpendicular to Roxas Avenue, which is another site for same purpose.  As a result, two greenbelts will be interconnected with each other.  This will greatly improve and enhance the environment of the area.

3. Roxas Avenue

Roxas Avenue is a potential greenbelt since it has two (2) planting strips located at both sides of the canal at the center of the road.  This strip is already planted to a number of trees but they are nor yet sufficient in number.  More trees of the recommended species should be planted and the area should be landscaped.  This belt can serve as the continuation of the greenspace at the Millenium Park that will lead all the way up to the intersection with Quezon Boulevard.  Since Quezon Boulevard is another proposed greenbelt, one long continuous belt spanning two major thoroughfares in the city will be the result.

4. Candelaria Street, Ecoland Subdivision Phase 2

This street will provide a vital link to the greenbelt that will start at Quimpo Boulevard.  Candelaria Street leads off from Quimpo Blvd. leading to the Overland Bus Terminal, the Hall of Justice and Ecoland Subdivision.  A row of mahogany trees planted along this street are already full-grown.  The belt should incorporate these existing trees and all trees to be subsequently planted should be of the same species.

5.0 Ecoland Drive, Ecoland Subdivision Phase 4

This avenue leads off from Quimpo Boulevard going towards the direction of Times Beach.  It starts at the back of the Double-R and Caltex establishments.  The road has a center island with a 4-meter width.  A large number of Acacia trees are planted therein but no means of proper access for pedestrians, such as pathways is provided.  Furthermore, the site is not yet landscaped.  Although it is still under the jurisdiction of the developers of Ecoland Subdivision, the City ENRO has been undertaking the maintenance of such center island.  It is proposed that this area be turned over to the jurisdiction of the city government through the City ENRO for the purpose of establishing the greenbelt.

If this study is fully implemented, Ecoland Drive will complete the long stretch of greenery that started from Roxas Avenue, going to Quezon Boulevard and to Quimpo Boulevard further down south of the poblacion.
 

ENVIRONMENTAL AND ECONOMIC BENEFITS OF 
GREENBELTS AND GREENSPACES

It is already of common knowledge that the environment is under threat from various forms of human activity. One of the most serious threats in the massive amount of waste put into the air, water and ground annually.  All around the world, thousands of places have been, and continue to be polluted by toxic chemicals, radioactive wastes and the like. Air pollutants come from a variety of natural anthropogenic sources.  As a rule, anthropogenic pollutants- the products of human activities- represent the most significant threat to the environment and its inhabitants.  The six major pollutants are carbon monoxide, sulfur oxides, nitrogen oxides, particulates, hydrocarbons, and photochemical oxidants. They come primarily from transportation, power plants and many types of  industry.

Effects

Air pollution affects human health in many ways.  Pollution episodes have numerous immediate effects, including discomfort, burning eyes and throats, colds and coughs. Heart attacks and death may occur in patients who have heart and lung disease.  Delayed effects also result from chronic exposure to air pollution, among them chronic bronchitis, emphysema, asthma and possibly lung cancer.

Many air pollutants affect domestic animals as well.  The most noticeable impacts of air pollution are on wild animals and on materials, such as, rubber, stone and paint.  Ozone, sulfur dioxide and sulfuric acid are the most damaging pollutants.  Crops and forests are also damaged by air pollutants, particularly ozone, sulfuric acid and sulfates.

Global Change

Scientists have long determined that air pollution can affect local weather.  For example, smoke from factories can substantially increase rainfall in areas downwind. In recent years, however, a growing body of evidence shows that air pollution can also affect global climate.

Each day the air is bathed in sunlight.  The air, water, lands and plants absorb the rest.  Absorbed sunlight is converted into heat, or infrared radiation, which is slowly radiated back into the atmosphere.  Eventually, all heat escapes the earth's atmosphere and returns to space.  As a result, energy input is balanced by energy output.

Scientists have discovered that certain air pollutants, notably carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and CFCs, may alter this delicate balance.  How do these gases affect the earth's energy balance?

Consider carbon dioxide.  Naturally occurring carbon dioxide allows sunlight to pass through the atmosphere and heat the earth's surface and radiates it back.  This process helps maintain the earth's temperature.  The balance can be upset, though, if concentrations of CO2 exceed normal levels.  As they rise, they reradiate more heat to the earth, causing the atmosphere to warm.  Glass in a greenhouse behaves similarly and thus helps reduce heat escaping from the interior of the structure.  Consequently, CO2 and others that act similarly are known as greenhouse gases.

Greenhouse Effect

Three of the four greenhouse gases, carbon dioxide, nitrous oxide, and methane are emitted by natural sources.  These gases, however, are also released in large quantity from anthropogenic sources.  CFCs come solely from human sources.  The production and release of anthropogenic greenhouse gases have risen rapidly in the past forty years, creating concern among many scientists and environmentalists over a phenomenon called the greenhouse effect or global warming, a possible global rise in temperature caused by a build up of gases that upset the earth's heat balance.

Global climate models predict that global warming could spawn bizarre and violent weather. Warming seas impart more energy to the atmosphere that generates such storms.  An increase in devastating storms could have potentially serious economic impacts as well by destroying crops and making food more expensive.  Property insurance would also rise.  Desert-like conditions may spread.  Agricultural neighboring regions could find their cropland rendered useless.  Global warming could make cities unbearable in the summer.  A great many plants and animals could face difficult times as the planet warms.  Practically every ecosystem on earth will be affected.

Solving the Problem Sustainably

With this issue, as with others, numerous solutions are available.  The most effective are those that strike at the roots of the problems, eliminating the harmful emissions of carbon dioxide, methane, CFCs and nitrous oxide.

To reduce atmospheric CO2 levels and stave off or stop the possible increase in global temperature will require a massive reforestation of the earth.  One of the practical ways to minimize the amount of these toxic gases in the air is to plant gas absorbent trees and other plant species.  A series of laboratory and field tests were conducted by the Environmental Management Bureau (EMB) to determine the varying degrees of resistance of various tree and other plant species exposed to high traffic density areas based on sulfur dioxide (SO2) and nitrogen dioxide (NO2) contents.  Plants classified as resistant were those that showed zero to twenty- percent injury per plant for at least sixty six percent of all plants of the same species in three test sites.
The government of Australia recently announced that it was embarking on an ambitious program to plant one billion trees by the year two thousand ten, partly to offset global warming.  A few other countries are following suit, among them China.  Norman Myers, an international expert on tropical forests, argues that replanting two point six million square kilometers (One million square miles) of tropical rain forests would reduce annual emissions of CO2 by two and a half billion (2.5 B) metric tons, or about forty one percent (41%).  Although this ambitious project would cost approximately one hundred billion dollars ($100 M), Myers argues that it is a small price to pay especially when one takes into account the potential economic damage caused by global warming.  Replanting could also bring direct economic benefits to developing nations from sustained timber yields, reduced soil erosion and sustainable harvest of forests.

People, through their individual efforts can help by planting trees on their own property.  They can also plant in areas suited for tree-planting activities or at denuded areas of existing forests.  In order to offset CO2 produced by an individual  person's lifestyle, four hundred trees must be planted.  A family of four would need to plant two and a half (2.5) hectares (or six acres) of fast growing trees to offset its lifetime CO2 production.  Obviously, not everyone can or has the capacity and resources to plant trees.  Thus, the government initiates reforestation projects, develop parks and other areas devoted to trees and other forms of greenery.  Private organizations, corporations and other entities also embark on similar projects.  An individual and the public in general, should take part and support these undertaking.  The environmental benefits redound not only to the proponent of these projects.  In the final analysis, it is the individual who will ultimately benefit from the result of this endeavor. 

Benefits

Trees contribute positively to the urban environment by providing greenspace screening and habitat for urban wildlife.  They help to ameliorate noise and air pollution.  They contribute to modify urban microclimate, add values to urban properties and provide aesthetic enhancement to what could otherwise be a total asphalt and arid environment.

Previous studies show that trees may contribute up to twenty five percent (25%) of the value of unimproved land suitable for housing development and up to twelve percent (12%) of the value of half-acre properties with houses.

Trees can modify the urban microclimate by (1) their shading effect, (2) increasing long wave radiation, (3) reducing wind speed (4) intercepting rain, (5) cooling the air by evapotranspiration, and (6) possibly raising the humidity of the air.

Strategically placed shade trees around small homes can significantly decrease energy required for space cooling up to eighty percent.  In hot climate areas, reduction in wind velocity and air infiltration rates by vegetation may produce additional energy savings.  Windbreaks lessen heating energy needs by lowering air infiltration rates.  Narrow dense belts of trees are effective barriers to noise.

Aesthetically, trees and shrubs provide their own inherent beauty in all settings. They enframe views, soften architectural lines, enhance and compliment architectural elements, unify divergent elements and introduce naturalness to otherwise stark settings.  Plants augment our aesthetic enjoyment by enhancing the environment in which our urban population lives.

The following summarizes the benefits of greening our environment:

Environmental benefits:
· Thermal tempering- trees and shrubs provide a cooling effect
· Carbon sequestration- photosynthesis reduces carbon dioxide in the air into oxygen
· Soil anchors- plant roots tend to bind soil and prevent erosion

Economic benefits:
· Tree lined streets improved property values
· Tree lined streets reduces heat thereby reducing cooling costs

Socio-Cultural benefits:
· Aesthetic value- green color produces positive psychological effects
· National pride- a green society is a job well done!
 

OBJECTIVES:

1. Simplify and define their respective functions and duties.
2. Minimize work force

FUNCTIONS:

Office of the Mayor:
1. The Mayor has the primary responsibility and corresponding authority for all urban greening projects
2. He has the supervision and control over the different offices under him as far as greening projects are concerned.

City Environment and Natural Resources Office (CENRO):
1. Act as the lead implementing agency in the implementation of urban greening projects of the city.
2. Provide for the technical materials as well as supervision of the urban greening projects.
3. Coordinate in the conduct of information drives of the city regarding its urban greening projects.

Plans and Programs Unit of CENRO:
1. Plan and layout the landscape designs for specific public greenspaces.
2. Coordinate with the City Planning and Development Office as well as with the Davao Beautiful foundation for urban greening projects.
3. Prepare and propose budget for the landscape construction and maintenance jobs.
4. Identify other needs like facilities e.g. nursery, equipment and tools and prepares plans for their procurement.
5. Monitor and evaluate greening and maintenance activities.
6. Keep records for future plans and program.
 

Field Operation Unit of CENRO:
1. The field operation unit of CENRO must coordinate with the City Engineer’s Office as well as with the Barangay Clean and Green Program of the city government as to the planning and implementation of urban greening projects. 
2. The field operation unit of CENRO is proposed to be divided into three sections, namely: the Nursery section; the Planting and Landscaping section; and Maintenance section.

Nursery section of Field Operation unit of  CENRO:
1. Undertake propagation of species of the right quantity and quality and supplies stock on time based on own need or requirement in the field.
2. Produce planting materials also for distribution to interested individuals and institutions engaged in greening in whatever form either free of charge or for sale.
3. Provide training in planting stock production and nursery management.
4. Develop on a continuous basis improved methods and techniques in the propagation of potential and proven species for urban greening.
5. Keep records of updated inventories and submits reports regularly.

Tree and Landscaping Section:
1. Approves landscape plans for private developments.
2. Issues Tree and Landscape Compliance Certificate for private developments. 
3. Implement the landscape construction plans or designs for particular public greenspaces in parks, plazas, gardens, streets, island avenues, etc.
4. Supervise site preparation planting and construction and sees to it that plans are followed.
5. Propose change of alternation plants species if the species required are not available or not conforming to the existing landscaping conditions.
6. Execute and supervise improvements of parks, plazas, gardens and other fixtures streets and roadside and others.
7. Keep records and submits reports regularly

Maintenance Section:
1. Program comprehensive maintenance activities for all public green areas and landscapes.
2. Sweeping and cleaning lawns, grounds and landscaped green areas.
3. Providing tree guards , stakes and ties, grasscutting and or mowing all turfed areas.
4. Pruning low lying branches, dead and decaying branches and stems.
5. Conducting tree surgery
6. Removal and replacement.
7. Keep records and submits reports regularly.

City Planning and Development Office
1. Coordinate with Plans and Programs Unit of CENRO in implementing urban greening projects of the city.
2. Initiates, prepares project profiles and design  for urban greening projects.

City Engineer’s Office:
1. Issues building permit for private developments.
2. Removes illegal structures within city parks/streets.
3. Provide assistance to the barangay in the maintenance of the urban greening  projects.
4. Provide vehicular support for the transport of planting materials to the barangays. 
5. Coordinate with Field Operation Unit of CENRO in the conduct of their operations  regarding urban greening projects.

Barangay Clean and Green:
1. Initiates and Implements urban greening projects in their respective barangay.
2. Coordinate with the field operation unit of CENRO in the implementation of  such greening projects.

Davao Beautiful Foundation
1. Coordinate with the Plan and Program Unit of CENRO in the implementation of urban greening projects.
2. Act as a conduit for the commodity for financial contributions that may received from the business sector for the implementation of the Barangay Clean and Green Program and ensures proper accounting of such donation.
 

RECOMMENDED SPECIES OF TREES AND PLANTS
SUITABLE FOR GREENBELTS, GREENSPACES AND PARKS

 The following are species of trees and plants that are suitable for the purpose of establishing these greenspaces and greenbelts in urban areas.  These species are those which have been identified by the Ecosystem Research and Development Service of the Department of Environment and Natural Resources (region 11).  These are trees and plants that can adapt well to an urban ecosystem.  They are moderately to highly resistant to the effects of polluted environments.  Furthermore, they contribute in reducing the level of pollution to an extent by absorbing air pollutants such as carbon dioxide and nitrogen oxide.  Planting them in parks and greenbelts places them at strategic locations since air pollution takes place at these places where there are roads and where human activities are concentrated.

1. Common Name : Narra
Local Name   :  Narra, Naga
Scientific Name  :  Pterocarpus spp.
Family           :  Fabaceae

Species Characteristics:
 A large tree usually with an irregularly fluted or deformed short trunk.  The tree is nearly deciduous for a short time during the dry season.  Leaves are alternate, simple and odd-pinnately compound; leaflets 7 to 11, ovate to oblong-ovate, smooth margin but wavy, blunt acuminate, thin glabrous 0.5 to 10 cm long, 2 to 8 cm wide, alternate, and shiny.
 Its flowers are numerous borne in axillary racemes mostly single flowers, very showy and fragrant.  The mature fruit is almost like flat and orbicular, dry, indehiscent pod, 4 to 7 cm in diameter, very shortly beaked, containing 0 to 5 seeds, its wings more or less reticulate and wavy.

Plant Condition / Location:
 Narra planted within the city of Davao are healthy and vigorously growing in school campuses, along roadsides and greenbelts or parks.

Propagation:
 The species is grown from seeds or asexually through cutting, stump planting and tissue culture however, this technique has not yet been perfected for large-scale application.  Other techniques are grafting, budding, marcotting and layering.  Seeds will be collected from superior mother trees.  When fruits or pods fall to the ground, collect them before they begin to open and germinate immediately or deteriorate.  Sow the seeds (usually in pods) in prepared 1 by 6-m plots with shallow drills 15 cm apart.  Cover the drills with soil.  Mulch with cogon and dry leaves during the dry season.  The pods can also be directly sown in plastic bags (5” x 6” x .004 mm) filled with topsoil or ordinary soil.  The seedlings of narra are considered ready for outplanting when it reaches 50 cm in height.

2.  Common Name      :  Palawan Cherry
Local Name       :  Pink Shower (Span.)
Scientific Name :  Cassia nodosa L.
Family         :  Caesalpiniaceae

Species Characteristics:
 Palawan cherry is an unarmed tree, attaining a height of 10 to 15 m.  The leaves are about 30 cm long, each divided into 5 to 12 pairs of elliptic leaflets 1 to 2 cm long.  Most of the leaves are shed before flowering starts.  The blooming period is from is from March to April.  The pink flower fading to white with age is about 5 cm long.  The cylindrical fruit is 30 to 45 cm long.  The young fruit is green, becoming black when ripe.  Numerous seeds are formed along the entire length of the fruit.  The seeds have waxy seed coats and long period of viability.

 Other ornamental trees in the Philippines with showy flowers and which are closely related to Palawan cherry are: 

Golden shower.  The flowers are red, turning orange and cream at maturity.  To hasten germination, it is necessary to make a slit through the seed coat to allow the early absorption of water by the embryo.  A sandy loam soil favors the growth and development of this plan.  It is believed that the reduction of water supply for mature plants from January to the blooming time will induce the early shedding of the leaves and eventual flowering.

 Palawan cherry  and the other trees of the bean family with deciduous leaves have similar adaptations for the survival of the individuals and the preservation of their own kind.
 
The species is used as ornamental shade or nurse trees.

Condition / Location :
 Palawan cherry planted within the city of Davao are healthy and vigorously growing along roadsides and school campuses.

Propagation :
 Palawan cherry is propagated through seeds.  Without pretreatment it takes months for the seeds to germinate.  To hasten germination and to increase the percentage of  germination it is necessary to make a slit through the seed coat to allow the early absorption of water by the embryo.

3. Common Name     :  Rain tree
Local Name       :  Acacia
Scientific Name  :  Samanea saman (Jacq.) Merr.
Family            :  Mimosaceae

Special Characteristics :
Acacia, commonly known as rain tree is a large spreading tree attaining a height of 20 m or more and a diameter at breast height (DBH) of more than 100 cm.  Because of its large and wide span, it is a favorite shade tree along streets.  The main axis (rachis) of the compound leaf has 4 to 8 pairs of leaflets. 
Changes in light intensity are the specific stimuli for the nyctatropic behavior or “ sleep movements” in many plants, especially legumes.  The branches of the rachis hang down and the leaflets fold together at night and cloudy days; during the day, the horizontal position is assumed.  The function of “sleeping movement” is not very well understood.  The shedding of most leaves during the summer months reduces the surface area for evapo-transpiration, thus, conserving water content of the plant.

Plant Condition / Location :
 Acacia are vigorously growing in public plazas, school campuses and roadsides as greenbelts within Davao City.
 

Propagation :
 The species is easily grown from seeds.  Seeds of rain tree germinate easily without treatment in 2 to 3 weeks.  Germination could be enhanced through the following pre-germination treatment:
1. Pour 1 liter or boiling water over ½ kg seed.
2. Stir gently and remove water after 3 minutes.  Replace hot water with cold water and soak for 24 hours.
The treated seeds is directly sown in seedbeds or in prepared polyethylen bags with appropriate germinating and growing media.  If to be sown in seedbeds, the seeds should be spaced at 10 x 10 cm and up to 2 cm depth.  For direct sowing, sow 1 seed per bag.

4. Common Name      :  Coronitas
Local Name       :  Lantana, baho-baho
Scientific Name :  Lantana camara L.
Family            :  Verbenaceae

Species Characteristics :
 Coronitas is an erect or subscandent, somewhat hairy, aromatic shrub; when erect usually 1-2 m high, when scandent twice as high.  The leaves are ovate, acuminate, toothed, 5-9 cm long.

Plant Condition / Location :
 Lantana planted within the city of Davao are healthy and vigorously growing along roadsides and residential lots and greenbelts as ornamental plant.

Propagation :
 Lantana is propagated by cuttings.
 

5. Common Name      :  Dapdap
Local Name       :  Dapdap
Scientific Name  :  Erythrina orientalis (Linn.) Merr.
Family           :  Fabaceae

Species Characteristics :
 Dapdap is a tree 10 to 15 m tall.  The trunk is stout with gray, smooth bark.  The thick branches are armed with short, black thorns.  The leaves are long-stalked with 3 broadly triangular leaflets, each 12.5 to 15 cm long.  The fruit (pod) is 15 to 25 cm long, about 2 cm thick and constricted between the red seeds.

Plant Condition / Location :
 Dapdap growing within the city of Davao are healthy and vigorously growing along roadsides, school campuses, parks and public plazas.

Propagation :
 Dapdap is usually grown from seeds and also by stem cuttings.  Seeds are soaked in cold/tepid water for 24 hours before sowing.

6. Common Name  :  India Rubber Tree
Local Name    :  Balete (Tag.) Indian Rubber Tree (Eng.)
Scientific Name  :   Ficus elastica
Family Name    :   Moraceae

Description:
 Ficus is a spreading glabrous tree reaching a height of 10-m normally starting as an epiphyte, sending down numerous adventitious roots from the trunk and larger branches.  Leaves are very coriaceous, smooth and shining, elliptic-oblong sharply and slenderly acuminate, 15 to 25 cm long, entire, the nerves very numerous, parallel; stipulates deciduous, membranous usually red, often as long as the leaves.  Receptacles axillary usually in pairs, sessile, smooth, greenish-yellow, about 1 cm long, oblong-ovoid.

Propagation/Distribution:
 The species is propagated by seeds.  Generally, it is found in the garden and parks.

Uses:
 The species is planted as a source of rubber before the introduction of the para rubber tree. It is also used for ornamental, fiber, and timber.  Nowadays, it is a popular garden and indoor plant sometimes planted in pots.

 The decoction of the aerial rootlets is used as a vulnerary.  The latex is administered to cases of trichuriasis.  The bark is often used as astringent and syptics for wounds.
 The leaves and stems contain calcium oxalate, saponin, tannin and fats.

7. Common Name  :  Kamagong (mabolo)
Local Name   :  Mabolo, balingata, itum-itum, ituman, kamaya 
Scientific Name  :   Diospyros Philippensis
Family Name   :  Ebenaceae

Description:
 Kamagong is a tree reaching a height of 20 m and a diameter of 80 cm.  Bark is blackish, rather fissured and uneven.  Leaves are 10 to 25 cm long, alternate, feathery, oblong or elliptic oblong, pointed at the apex, rounded or obtuse at the base.  The upper surface is green, shining glabrus and the lower surface softly pubescent with a appresed, pale or peach-color hairs.  Staminate flowers are short-peduncled, about 7-flowered cymes.

Propagation/Distribution:
 The species is grown from seeds.  The species is widely distributed in the Philippines.  The species flowers from February to April.

Uses:
 The wood of Kamagong for carvings and special furniture.

8. Common Name     :   African Tulip
Local Name       :   African Tulip
Scientific Name  :  Spathodea Campanulata
Family            :  Bignoniacea

Species Characteristics:
African Tulip is a flowering medium-sized, evergreen tree that has been introduced to the Philippines.  The wood is soft and sturdy trunk forms buttresses.  The leaves are shiny dark green, 30 t0 40 cm long, divided into 4 to 8 pairs of leaflets, with an extra one on the tip assuming a feather-like form.

Plant Condition/Location:
African Tulip are healthy and vigorously growing along hospital thoroughfare, school campus, parks and roadsides within Davao City.

Propagation:
African tulip flowers several times a year.  It can be propagated by seeds and by stem and root cuttings.
 
Recommended Species of Ornamental Trees
The following are recommended species of trees and palms that can be planted for ornamental landscape:
1. Candle Tree (Parmentiera cerifera)
2. Calabash Tree (Crecsentia cuiete)
3. Buttercup Tree (Cochlosperum vitifolium)
4. Bitongol (Flacourtia rukam)
5. Fireball (Calliandra haematocephala)
6. Balitbitan (Cynometra ramiflora)
7. Hongkong Tree (Bauhinia blakeana)
8. Pencil Cedar (Juniperus virqinianus)
9. Portuguese Cypress (Cupressus lusitanica)
10. Macarthur Palm (Ptychosperma  macarthuri)
11. Bottle Palm (Mascarena laqenicalulis)
12. Palmera (Chrsalidocarpus lutescens)
13. Palawan Cherry (Prunus junghuhnianus)
14. African Tulip (Spathodia campanulata)
15. Alibangbang (Bauhini spp)
16. Calachuchi (Plumera acutifolia)

*Coconut and other high growing palms should not be allowed.
   Location of Garden Plants
             1.  Garden plants may be allowed on the road along the primary line.
        2.  Garden plants may be allowed on alleys and pathways.

 Recommended Species of Garden Plants
The following are recommended species of garden plants which can be planted under or near primary lines:
1. Budha Bamboo (Bambusa Ventricosa)
2. Baston de San Jose (Cordyline tersinalis)
3. Tigre (Sanseviera prain yar laurentii)
4. Ornamental Banana (Musa Ornata)
5. Yellow Plantain (Heliconia bihai)
6. Red Leaf Heliconia (Heliconia metallica)
7. False Bird of Paradise (Heliconia platystachys)
8. Narrow Leaf Heliconia (Heliconia psittacorum)

Location of Electric Poles
3. All proposed poles shall be 10.6 meters (35ft)
4.  All proposed poles shall be installed 15 cms. From the gutter of the road.

**Proposed Amendment Filed in Congress Through House Bill No. 13376 (known as the "Greening Act of 1994")
 In accordance with P.D. 953 and 957 as amended by P.D.1216 and as further amended by HB 13376 the following should be required :
C. Developer / owner of industrial estate and commercial complexes must provide within the land an area of 1 hectare or more as defined within the boundary, a plot ratio of 70% for development and 30% as green area.  This green area is an open space that should be exclusively devoted for parks, playground  and recreational use.  This means that amenities such as swimming pools, tennis courts, playgrounds, sandpits, pavilions, fountains, etc. may be included within the 30% green area.
Excluded in the 30% green area are car parks, road reserves, drain reserve, bin centers, septic tanks, electric substations and planters and planting area within the buildings.
All green area must be turfed or landscaped.

D. In the case of residential subdivision development with one or more hectares shall likewise reserve 30% of the gross area for open space allocated exclusively for parks, playgrounds and recreational use.
Specifically, tree-growing site in these open spaces shall cover the following :
- Nine (9) percent of gross area for high density or social housing (i.e. 66-100 family lots per gross hectares).
- Seven (7) percent of gross area for medium density or economic housing (21-65 family lots per gross hectares).
- Three (3) and a half (3 1/2) percent of the gross area for low density or open market housing (10-20 family lots and below per gross hectares).
Developer / owner is encouraged to provide for as much area and planting strips as possible to make living more environmentally wholesome. 

 
 
PROPOSED GUIDELINES AND TECHNICAL REQUIREMENTS
 

These guidelines and technical requirements are intended for developers of private property, as well as for the city government.  These requirements apply to two groups: (1) private developments, and (2) public parks and roadsides.  The requirements for the first group apply to private developers of residential, commercial and industrial lots. These guidelines and requirements are to be applied on the thirty percent (30%) retention area mandated by law.  On the other hand, the city government is required to comply with those in the second group in establishing public parks and in developing greenbelts along roadsides.  They are also designed to assist architects and engineers in meeting the tree planting and landscaping requirements.
 

GROUP I Residential, Commercial and Industrial Developments

1. Provisions for Planting Strips and Tree Planting within Development Sites

1.1 A planting strip should be provided in sites with lot frontages abutting national and city roads. It should be within the road right-of-way. The strip does not replace or supersede other adopted/statutory setback requirements but may form part of the green buffer zone where applicable.

1.2 The planting strip should be at least one (1) meter in width.  It should be alongside the road, between the roadside and the walkway or sidewalk.  The walkway or sidewalk should not be less that two (2) meters in width.

1.3 As much open space and planting strips possible should be provided for, as required in PD 957 within the residential, commercial or industrial lot in accordance with the two preceding requirements. 

1.4 Every owner of these developments is required, among others, to plant trees in the designated open space and along such planting strips.  Proper distances should be observed for tree planting in the latter, depending on the specie.

1.5 The retention area should be turfed and landscaped, as approved by the Tree and Landscaping Unit (TLU) of the City Engineer's Office or such other office issuing the building permit.

1.6 A one- (1) meter wide planting strip should be provided along the driveways and roads within the development if these are not located adjacent to the 1.0-meter strip required in 1.1. 

2. Screening of Bin Centers, Septic Tanks and Substations

2.1 A planting strip of one (1) meter should be provided for the planting of shrubs or hedges to screen bin centers, septic tanks and substations.

3. Planting and Maintenance of Trees and Plants

3.1 All planting areas should preferably be a gradient. Where trees are to be planted, the gradient of the ground should not be steeper than 1:2.5.

3.2 The minimum size of a tree planting hole should not less than 1m x 1m x 1m. The hole should be backfield with a mixture of good topsoil and sludge or compost in the ration of 3 parts topsoil to 1 part sludge or compost.

3.3 All tree saplings should be staked and tied so that they would grow upright.

3.4 Weeding of tree bases and application of manure/chemical fertilizers should be carried out regularly.

3.5 Low branches and dead parts of trees should be pruned.

3.6 Garden and ornamental  plants should be planted to complement the trees and to beautify the site.

3.7 Spraying of pesticides should be undertaken as and when necessary.
 

4. Plans to be Submitted, When Seeking Planning Approval

4.1 The plan and layout for the site development shall be submitted to the City Engineer's Office or such other office that is tasked to issue the building permit.  A tree and landscaping plan for the 30% retention area shall be included along with the site development plan for the remaining 70%.

4.2 The plan for the retention area should conform to the tree and landscaping requirements.  This is submitted to the tree and landscaping section (TLS) of the City ENRO Field Operations Unit.

4.3 Site visits by the TLS shall be scheduled with the owner-developer.  The TLS will inspect and verify the appropriateness of the plan.  Thereafter, the tree and landscaping permit will be issued. A copy of this permit shall be submitted to the City Engineer's Office in order that the building permit for the 70% area will be issued.  If the plan is rejected, the owner-developer will modify the plan and resubmits the same. 

4.4 After the permit is issued, planting and landscaping should be commenced.  The owner-developer shall request for a second site visit.  The second visit should be done within 15 days after the request is made. 

4.5 If the TLS approves of the planting and landscaping, a compliance certification (Temporary) is issued by the TLS.  This temporary certificate is valid for one year.  During this period, the owner-developer is responsible for the maintenance and upkeep of the site.

4.6 The TLU schedules a final site inspection on or just before the date of the expiry date of the temporary certificate, with notice to the owner-developer.  On site inspection, the TLU inspects the general condition of the trees and landscapes and recommends the approval of a permanent tree and landscaping compliance certificate.

4.7 The owner-developer continues the maintenance program.  The condition of the trees, plants and landscaping are monitored by the TLU.

4.8 The City ENRO will monitor the maintenance and development of the retention area.
 

GROUP II Public Parks and Roadsides
1. Provisions for City and National Roads
1.1 A planting strip should be provided along national and city roads so that trees and plants can be planted for the greenbelt.  This strip should be turfed and landscaped. 

1.2 The planting strip should not be less that one (1) meter in width.  It should be alongside the road, between the road and the sidewalk or walkway.  The sidewalk should not be less that two (2) meters in width.

1.3 Trees and plants are to be planted on this area.  Trees should be planted at the center of the strip and proper distances between them should be observed.  Furthermore, trees should not be planted within twenty (20) meters of any traffic junction or pedestrian crossing to ensure that no "blind spots" are created.

1.4 Only single species of trees should be planted per street or road.  This serves to create a smooth and attractive belt of trees.  For national highways and major avenues, species should be varied at  least every kilometer or half a kilometer, respectively.

1.5 The choice of tree species should take into consideration its size, height and crown.  They should also have the characteristic of high branching.  The presence of utilities such as electric and light posts and drainage should be taken into consideration.

1.6 Aeration and perforated slabs should be provided at intervals to serves as pathway for passengers boarding/getting off vehicles or pedestrians crossing the road.  This will prevent pedestrian damage to the trees and plants.

1.7 Center islands should be planted with garden and ornamental plants.

1.8 A center divider of at least four (4) meters must be provided for all roads to be constructed which exceed fifteen (15) meters in width.  The greenbelt may instead be planted in this area, instead of on the roadside.  Utilities such as electric posts and underground drainage may be placed on the side of the road.
2. Provisions for Public Parks and Open Spaces

2.1 Sidewalks and walkways should be constructed to provided access to and from the park.  They should have a width of at least one (1) meter.  This may be fully concreted or be made of aeration or perforated slabs.  These sidewalks and walkways should be established at points where pedestrian circulation and efficient access from other areas is maximized.

2.2 Central pathways and other footpaths should also be constructed to provide access within the parks and open space.  These should only be made with aeration or perforated slabs to retain some of the greenery on the soil surface.  The width should not exceed three (3) meters in order to retain as much greenspace as possible.

2.3 These pathways and footpaths should be built around the site without necessarily interfering with the landscaped areas and the tree plantings.  Hedges should be planted alongside the pathways to soften the visual impact of the concrete path or slabs.

2.4 Benches should be placed along the pathways and on the open space available.

2.5 Lamposts should be placed at appropriate distances between the trees.  The prescribed distance is six (6) meters apart.  If electric wires will have to pass above the park,  they must be placed at points where there is least interference with the aerial space of the park.

2.6 Medium to large-sized species of trees should be planted in these sites to provide shade.  Garden and ornamental plants should be planted around the trees to complement the latter and to beautify the site.  The area planted to these trees and plants should be properly landscaped.

2.7 Low railings or thorny plants may be placed around the perimeter of the park to ensure that people only use the designated walkways or pathways in going to and from the park.

2.8 The City ENRO is charged with the maintenance and  development of these public parks and open spaces.
 

NOTE: The land area for proposed parks and open spaces should comply with the minimum requirements provided for in the Comprehensive Development Plan of Davao City.  As much space possible, over and above the planning standards required by the Housing and Land Use Regulatory Board should be allocated.
 

CONCLUSION AND RECOMMENDATIONS

 The establishment and development of greenbelts and greenspaces  in Davao City is a crucial matter  that should not be the concern of the city government alone.  A government does not make a city, people do.  Greenbelts and greenspaces provide one of the means by which the urban environment is preserved and maintained in the face of rapid development.  Urban development in cities interferes with the natural life processes and the ecosystems therein.  More importantly, it brings about pollution and deterioration in the quality of the air that we breathe. 

We have already discussed the environmental and economic benefits of having these greenbelts and greenspaces in our local environment.  The value of having  these trees and other forms of greenery is so vital.  They improve the air quality of the city because of their absorption capacity as to the pollutants in the air.  They also provide aesthetic and psychological benefits in a place that is slowly transforming into an urban jungle.  Trees provide places of relaxation and rest.  They serve as balancing factors in a concrete-and-steel environment.

With its immense land area, Davao City has all the capacity and potential to transform itself into a veritable landscape of greenery.  The city government has embarked on a number of projects intended to transform Davao into a clean and green city.  At present, the city government has the "Barangay Clean and Green" Program with a number of offices involved.  The basic unit of government has been tapped to provide base support for this project.  This program should be continued because it requires the involvement of  people at the primary levels of our government.  From the Mayor down to the ordinary barangay residents, everyone contributes in his or her own capacity.  Thus, in the beginning, success is ensured to a certain degree because you involve the same people who will eventually benefit from the long-term benefits of the program.  They develop a sense of involvement because this program is not merely imposed upon them.  They make the program work because they themselves are involved in turning the program into a reality.  The other benefits of barangay involvement is that the values of discipline, community spirit and concern for the environment is developed.  As a result, an altruistic feeling in inculcated in the public. 

The involvement of non-government organizations, private corporations and socio-civic groups has already ensured the success of some of the existing programs of the government.  They provide much needed support and resources that complement the limited capability of the government.  However, these entities should not be left on their own in doing their share in the greening of  our urban landscape.  The guidance, control and supervision of the city government should be in place in order that uniformity and efficiency is ensured.  As shown in the proposed organizational structure of the Clean and Program of Davao, the city government still takes the lead role in achieving this common purpose.  The capability and resources of these sectors should be further tapped in areas of fund-raising, promotional support for public awareness and manpower. 

Previous programs adopted in Metro Manila for its own Clean and Green were the 'Adopt-a-Street/Park', Fund-rasing activities, and the 'Plant-a-Tree' program.  Furthermore, the Community Welfare Sevices (CWS) unit of the Reserved Officers Training Course (ROTC) of the local schools, colleges and universities should be tapped.  The city government can enter into memorandums of agreement (MOA) with these educational institutions.  They are also be subject to the supervision and control of the appropriate office involved in urban greening.

This study has found that there is still so much to be done as far as technical and infrastructure are concerned.  Due to the number of offices and agencies, both national and local, involved, there are bound to be variations in the manner by which these urban greening projects are to be carried out.  There should be uniformity in the guidelines and technical requirements in establishing these parks, greenbelts and greenspaces.  As seen from the results of the case study for specific parks, different planners and architects use their own plans in building these parks.  Interviews with two city offices involved in urban greening reveal that they are given such wide latitude in planning these sites.  As a result, vital considerations such as tree species, provisions for access, landscaping and maintenance requirements are dealt with differently.  There is no uniformity at all, thus these parks and open spaces are built differently.  There is no sense of oneness with the totality of the urban environment.  Developers of private property are not without any fault in this respect.  As mandated by law, thirty-percent of the development site is to be retained for open space.  No specific guidelines are applied in complying with the statutory requirement.  To make further complicate matters, the question of actual compliance with the 30% rule always comes up.  The city should be vigilant enough in applying the full force of the law in ensuring that private developers comply with it.

For those reasons, this study has come up with proposed guidelines and technical requirements.  It is recommended that these guidelines, or such law based on such guidelines be enacted as law by the legislative body of the city.  This will ensure that a uniform procedure and standard is followed in both private developments and government projects.  Furthermore, a new city ordinance involving the sidewalks or walkways should be passed by the city council in order that the guidelines and technical requirements will be complied with.  Data and interviews from the office of the city engineer reveal that the city has no specific and all-encompassing requirements for sidewalks.  Resolutions of the city council for the provision of sidewalks are made on a per-street basis.  Property owners are also given the option to either have an open-air sidewalk in front of their lots or have the arcade-type walkway.  In the latter, the building extends over and above the sidewalk but not extending beyond the edge of the roadside.  Open-air sidewalks must have a width of at least one and a half (1.5) meters.  On the other hand, arcaded sidewalks must have a width of at least three (3) meters.

It is proposed that a city ordinance should be passed requiring a minimum width of three (3) meters for all sidewalks in the city.  They should be the open-air type only.  The one-meter planting strip shall be taken from this provision.

Legal steps should also be taken to safeguard the gains that have been achieved so far.  In the case of some of the existing parks, two (2) in particular need legislative protection in order to preserve their integrity as a public park.  These are the Millenium Park and the Clifford Park.  Even though they are designated and maintained as parks, city records show that they are still classified as road islands.  They should be given legal classification as parks so that they will be maintained as such without any possibility that their use and purpose will be changed in the future.  Future parks should be given classified as such by the city council to ensure their legal protection.

The city government should continue to look for available lands for the establishment of parks and other open spaces.  We should not be merely contented with what we have now.  The Comprehensive Development Plan (CPD) of Davao City reports that much of the city's land area is agricultural land.  Thus, there is ample space available for more parks and open spaces can be rationally drawn from these areas.  At present, 105 hectares or only 0.78 percent of the total land area is devoted to parks and open space.  However, the classification of "parks and open space" also includes cemeteries, golf courses and other vacant spaces.  Thus, the total area devoted for parks and open spaces that can be utilized as greenspace is much smaller that the figure given.  Regarding that classification, it is proposed that a separate category should be created for parks and open spaces alone.  These are the places where people can actually go and relax, where active or passive activities can be made.  In all areas outside of the poblacion, e.g. Calinan, Toril, and Tibungco, available land areas should be identified.  The standard ratio prescribed by the CPD and the Housing and Land Use Regulatory Board (HLURB) is 500 square meters per 1,000 population.  This ratio should be increased as to the area required.  This way, the purpose and benefits of greenspace can be achieved better.  These are reforms that should be made in the CPD.  These reforms will make the CPD more attuned with the potential of the city's land resources.

In the construction of national or city roads, the provisions for sidewalks and more especially, of the planting strip should be enforced.  This provision shall ensure that the technical requirements that will be hopefully passed into law by the city council will be complied with. 

In sum, all these programs and requirements provide the important framework towards realizing our goal for a green Davao.  As a result, a clean and healthful environment is achieved.  The most crucial part though, is the concern and involvement of the people, from the highest official down to the ordinary resident.  As discussed at the outset, a government does not make a city, people do.  People are the moving force in any place or environment.  They make or break whatever programs or projects the government may initiate.  If you involve them, you are also empowering them.  You give them a sense of control and responsibility for the future of our environment.  You develop an altruistic feeling for everyone. 

There will always be costs and initial consequences in pushing the greening of Davao.  The long-term benefits far outweigh the present factors that may prevent the realization of this goal.  The attitude of everyone must be oriented towards moving towards that goal. 

The Davao Clean and Green program has all the capability to achieve its purpose.  Based on this study alone, the proposed pilot group of areas will very well advance the progress of the city's own greening program.  By redesigning and 'retrofitting' the existing parks and open spaces in accordance with the prescribed guidelines and requirements, we will have dual-purpose parks in due time.

 The greening of Davao has so much promise.  All it takes is involvement of the public, the political will of our city government and sincere efforts of our leaders and officials.