application of vegetation analysis and gis

ASCOT Research International Journal, Volume 3, December 2010

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Vegetation Analysis and GIS: Its Application

to Sustainable Forest Management

and Biodiversity Conservation

RB J. Gallego1

1Director, Department of Forestry and Environmental Sciences

Aurora State College of Technology, Baler, Aurora, Philippines

e-mail:[email protected]

ABSTRACT Resource databases compiled in the system are very crucial to meet the

requirements of sustainable forest management. The compilation, analysis, and

evaluation of these databases, established as resource information system, can

define the management interventions appropriate for a specific area. The study

was conducted based on the above mentioned principles as part of the MSc.

study. Databases were created from the results of data sourcing and inventory. in

terms of species composition. The floristic analysis showed that species of

Dipterocarpaceae still dominates in the area despite of being intensively logged

few years ago. The potential regeneration of the area is now getting better since

the vicinity has plenty of saplings and seedlings of valuable species.

Vegetation analysis, by principal components, was conducted to show

relative correlation between species composition and environment variations like

elevation, slope and soil types. The results showed no correlation at all.

Considering faunal assessment and analysis, Philippine endemic and endengered

species which needed conservation and protection were found in the area. Along

with these ample data gathered stored in the system, simple GIS analysis where

generated to identify areas with important biodiversity. Added to this are the

areas that needs enrichment planting and areas needed silvicultural treatments

like liberation cuttings.

INTRODUCTION

The Philippines is included among the countries with lush tropical rain

forests. Reference [1] reported that 50% of the country was covered with natural

forest. The latest survey showed that the remaining forest cover dropped from 15

million in 1911 to only 6 million hectares. The Philippines now faces the dilemma

of deforestation. Droughts, floods, altered climatic conditions, and soil erosion are


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just the few among such consequences. The aftermath of environmental

destruction alarms everybody and the burden of concern rests on forest managers

and environmentalists who work directly with forests.

Forest resource management plays an important role in the conservation of

the remaining natural forest resources that will play a critical role in attaining both

economic and ecological goals. One prerequisite towards effective management

of a forest is through gathering of ample and reliable information about the forest

itself and compiling them in an orderly system for analysis and retrieval.

Primary data about the forest usually comes from forest inventories. Forest

inventory is the primary approach in dealing with forest resource management

because it shows record of location, extent, nature, condition, and productive

capacity of a nation’s forest. Today, inventory and planning of forests involves

the use of aerial photographs. Aerial photography is widely used as a component

of a more complex inventory design. If sampling techniques have to be carried out

by field measurements, aerial photos are the best tools for stratification [2].

Furthermore, Geographic Information System (GIS) solves complexities in

managing inventory and remote sensing data. GIS technology has the capability

for storing, exploring and querying data.

Geographic Information System (GIS) is an effective management tool that

serves as clearinghouse for all relative information about any forest area. It plays

important roles in defining management interventions appropriate for the area of

interest. Integrated in the feedback loop system of managing resources, GIS

enables the manager sees whether or not the management of the area of interest is

in accordance with sustainable forest management criteria and indicators. RIS

gives the manager the cues where and when to make adjustments to current

interventions so that the sustainable forest management stays on course.

At present, most of the forest management interventions are implemented

directly to areas of interest without knowing the possible effects of the results.

Although these interventions are based on applicable concepts, one should note

that the applicability of some concepts varies from case to case depending on the

actual situation of the area of interest. The health of our remaining forest

resources should not be sacrificed to justify faulty management decisions. In this

regard, the need to establish GIS coupled with some vegetative characterization

techniques like vegetation analysis is essential in managing forest resources like

that of ASCOT Reservation Area in Aurora Province. The current study was

conducted in partial fulfillment of the requirements for a MSc. in Forestry [3].


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The Role of GIS

Reference [4] and [5] identified the need for accurate, scale-controlled

maps and attribute database derived from site-specific inventories. This could be

possible through a computer system capable to store, retrieve, update inventories

and create site-specific resource map.

Furthermore, [6] cited some requirements for an effective resource

management. He mentioned that resource inventory should be specific and the

means of analyzing and managing information should be sophisticated enough to

address environmental issues.

A Geographic Information System (GIS) allows sophisticated handling

and analyzing information. The user can use his creativity and knowledge in

manipulating one or several parameters or in creating and testing models based on

hypothesis. This will allow the user to see the outcome of forest operations before

it is being applied in actual situation [7]. In addition, GIS and Remote Sensing

(RS) have wide applications to assessment and allocation of resources,

environmental monitoring, determination or prediction of vegetation or wildlife

habitat, and for archaeological and harvest scheduling purposes. The application

is inventive because the user has the full control over the use of the system based

on its personal preference, objectives, and the available resources.

A GIS can also provide solutions to sophisticated problems in

management like locating or geo-referencing, forest condition and trend

assessment, pattern analysis and modeling [8].

METHODS

1. Vegetation Analysis

Floristic composition can be analyzed by identifying the species and

families of trees encountered within inventoried plots. Sorensen`s Similarity

Index Formula [9] was a helpful tool in comparing plots pair-wise based on index

of similarity. The index has the following formula:

IS= (2C/A+B) x 100

Where: IS= Index of similarity

C= No. of species common to two plots

A= Total no. of species in plot A

B= total no. of species in plot B


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RESULTS The study was initiated to provide maps, aerial photographs, reports and

other related documents regarding the area of interest. It was followed by

inventory preparation, aerial photo-interpretation, establishment of continuous

forest inventory (CFI) plots, and data gathering on established CFI plots.

1. Inventory Results and Analysis

After doing inventory, data were collated and analyzed to determine the

resource composition of the area. This present study was identified 154 species

belongs to 37 families. The study revealed that the area is dominated by the

species belongs to the family Dipterocarpaceae. The presence of pioneer tree

species in the area is due to the fact that the area is a logged over forest of which

gaps were opened for their emergence. The average tree density of the area is 463

individuals per hectare. In terms of saplings, the area is dominantly covered by

species belonging to family Dipterocarpaceae, Euphorbiaceae, Moraceae,

Lauraceae, and Meliaceae. The average sapling density of the area is 3,157 stems

per hectare.

In contrast wildlings distribution of the area is minimal. Overcrowding by

saplings could have possibly inhibited their presence. Whenever wildlings are

present in any given subplot, they are mostly composed of lesser-used species. In

terms of non-timber products, only palm species were roughly estimated. The

results showed that there are 13 species of palm in the area with the average

density of 3 individuals per square meter.

Based on simple faunal inventory and analysis, the area holds six bat

species, eleven birds, four frog species, and one small non-volant mammal.

Among the captured fauna, mostly were identified as Philippine Endemic species,

three bird species were identified as Near Threatened, and one bat species as

Vulnerable or considered at a low level of endangerment.

2. Vegetation Analysis

Vegetation analysis was conducted to provide information on the

distribution of species as a function of the environmental factors. As to the results

of the study, no distinct groupings of species in relation to the environmental

gradients of elevation, slope, and soils was identified. The area is heterogeneous

in nature and the results of the study might be attributed to the subjective

sampling of CFI plots (Figure 1).

3. GIS Application on Resource Analysis

Stand and stock analysis were used to demonstrate density and volume

distributions for each species group. The results showed that the density and


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volume of lesser-used species dominates the lower diameter classes. However,

dipterocarp and other common hardwood (OCH) groups dominate the upper

diameter classes.

Regeneration and faunal analysis were conducted also to determine the

distribution of regeneration and faunal components in the area respectively.

After resource analysis, resources information was stored in a database.

Appropriate GIS databasing procedures were followed to create a cell-based

database [10] (Figure 2) that contains information on slope, soil type, total

volume, total density, volume of species groups, volume per diameter classes and

many more.

Resource

databases were subjected

to surface analysis of the

GIS and different

resources were mapped

geographically. This

present study produced

density, volume, sapling,

and wildling distribution

maps. Each map reveals

the content of every point

in the area whether in

terms of number of

individuals or in terms of

volume.

4. Establishment of Protocols

The study also includes the establishment of practical protocols to allow

repeatability of results and improvement of accuracy. In this regard, protocols on

stratified random sampling with the aid of aerial photograph are recommended.

Additionally, protocols on vegetation analysis to relate vegetative data to

environmental features of the area were also established to benefit entities that

wish to duplicate the same endeavor.

Figure 1. Vegetation analysis showing similariry index of

plots along gradients of elevation (yellow, green and red

corresponds to low, mid, and high elevations respectively).


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5. Use of GIS in Identification of Areas for Management and

Conservation

Furthermore, a given natural forest resource can be mapped showing its

boundary including specific features that are of extreme interest in management

and conservation. The GIS query, sort, and extract of data relevant for

management and conservation produced the following: areas for enrichment

planting, areas that need silvicultural treatments, and areas with biological

importance.

Finally, one of the aims of this

study is to propose management

schemes for the area that are in line

with the criteria and indicators of

sustainable forest management [11].

Management schemes proposed

include aspects on legal and policy

framework, sustainable and optimal

production of forest products,

environmental protection, plantation

management, and GIS/RIS

framework.

V. RECOMMENDATIONS Many automated technologies are recognized to make substantial

improvements in the manner in which inventories are conducted and databases are

created. For better study results the study, I recommend that one should search

appropriate methods, procedures and even tools that could give substantial

information regarding forest resources. During the actual conducting of the study,

several problems surfaced especially in choosing appropriate methods of

sampling and inventory designs that could give results with much higher

accuracy. If one will replicate this kind of work in other areas, the following

recommendations are to be considered.

1. Use of RIS is highly recommended in managing complex forest resources.

2. Use and monitoring of continuous forest inventory (CFI) plots is

recommended especially when the purpose of management is to

perpetuate optimum levels of resources over a long period of time.

3. Steps in creating resource databases should be followed and improved in

future research projects that should be conducted.

Figure 2. Cell-based resource database for

ASCOT forest area.


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4. Management schemes identified are recommended for implementation by

ASCOT. This is to utilize the system and the databases to its full extent in

maintaining forest productivity and sustainability. It should be mimicked

in other areas also.

5. If not hindered by financial constraints, use detailed wildlife study instead

of rapid biodiversity appraisal. This is to reflect other important species in

the area that are not recorded due to incapability of the methods and the

researcher.

6. Density and volume maps needs to be verified in the ground. Ground

truthing will enhance the reliability of the study and will test the degree of

accuracy of the RIS system in calculating densities and volumes at any

point of the area given only the data from sample plots.

REFERENCES

H. N. Whitford, The Forests of the Philippines, Vol. 1: Forest Types and

Products. Bureau of Printing, Manila, 1911.

H. Kenneweg, , H., Principles of Aerial Forest Inventory. In: “Application

of Remote Sensing and Geographic Information Systems in

Managing Tropical Rainforests and Conserving Natural

Resources in the ASEAN Region. DSE/AIFM/FAO, Kuala

Lumpur, Malaysia. Pp. 116 - 130. 1991.

A. Lyyssonen, Assessment of Forest Resources for Management. In:

Proceedings of the Eight World Forestry Congress, Diakarta,

Rome: Food and Agriculture Organization of the United Nations,

1978.

S. H. Smith, Information Needs for Activity Planning in Forestry. In-place

inventories, principles and practices: Proceedings of the national

workshop. Orono: University of Maine. 1981.

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Modeling In IDAHO: Meeting The Challenge Through

Organizational And Technological Innovation. Journal of

Forestry, Vol. 94 No. 2. pp. 16 – 20. 1996.


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F. Croft and B. Kessler, Remote Sensing, Image Processing, and GIS:

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pp. 1996.

I. Bayer, Introduction to GIS. In: Application of Remote Sensing and

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Rainforests and Conserving Natural Resources in the ASEAN

Region. DSE/AIFM/FAO, Kuala Lumpur, Malaysia. pp 220 -

252. 1991.

D. Mueller-Dombois and H. Ellenberg, Aims and Methods of Vegetation

Ecology. John Wiley and Sons, New York. 1974.

N. C. Bantayan, GIS-Based Assessment Monitoring And Evaluation

(GAME): An Unbiased And Transparent Approach To

Sustainable Resource Development And Management.

Unpublished Professorial Chair Lecture, , College of Forestry and

Natural Resources, University of the Philippines Los Baños.

March 5, 2004.

S. Higman, S. Bass, N. Judd, J. Mayers and R. Nussbaum, The Sustainable

Forestry Handbook: A Practical Guide For Tropical Forests

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