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The use of Remote Sensing and GIS to Support Sustainable Management of Tropical Forest in East Kalimantan, Indonesia

The use of Remote Sensing and GIS to Support Sustainable Management of Tropical Forest in East Kalimantan, Indonesia

Robert Aguma and Yousif Ali Hussin

Forest Science Division, International Institute for Geo-informatics Sciences
and Earth Sciences,
ITC, 7500 AA, Enschede, Netherlands,

Tel : (31)53-4874-444,
Fax: (31)53-4874379,

Email : [email protected]


Abstract

Tropical forest degradation and/or deforestation are issues raising great concern among conservation scientists the world over. In particular, the rate of destruction of tropical forests, through the large extent of commercial logging has attracted a lot of attention. Moreover, many studies and reports indicate that this destruction is on the increase, given the rising demand for wood products from tropical forests, with the rising world population. As tropical forest destruction increases, so does the demand for their sustainable management from sections of people with environmental or conservation concerns. Consequently, at both international and national levels, a number of initiatives have come with suggestions of criteria and indicators for sustainable forest management determination. However, most of their propositions are still very broad and rarely find appropriate applicability at the Forest management unit level. This study looks at some ecological criteria and indicators developed by one such type of organisation in Indonesia, known as Lembaga Ekolabel Indonesia (LEI). The objective of the study is to demonstrate how remotely sensed data could support sustainable forest management by verifying some ecological criteria and indicators for tropical timber certification.


Introduction


The issue of tropical forest degradation/deforestation has been at the centre stage of controversy in terms of its environmental consequences for almost three decades. This has raised a lot of concern at international scale, particularly regarding the impact of logging activities on the sustainable function of forests. A study by the International Timber Trade Organization reports that less than one-tenth of tropical forests are managed on a sustainable basis. The growing international concern has led to an increasing demand for the sustainable management of forests, which has led to the development of criteria and indicators for assessing sustainable forest management.

The ecological criteria, indicators and verifiers used in this research were selected from among a set already developed by the Indonesian Ecolabeling Institute or Lembaga Ekolabel Indonesia (LEI). As a first step of working towards a credible forest certification system, LEI has come up with a list of criteria and indicators grouped under the three major categories of; productive, social and ecological functions. Under the ecological functions, 2 criteria and 19 indicators have been listed, categorized as: Criterion 1 (the stability of ecosystem) with 11 indicators, and criterion 2 (the survival of endangered/endemic/protected species), with 8 indicators. From the set of indicators listed under criterion 1, 2 indicators (E 1.3 and E 1.4) and five verifiers have been selected as follows:

The objective of the study is to demonstrate how remotely sensed data could support sustainable forest management by verifying some ecological criteria and indicators for tropical timber certification. Within the framework of this study, one ecological criterion, two indicators and five verifiers were selected from a list already developed by LEI. Specifically, the study aimed at using optical satellite remotely sensed images (i.e. Landsat-TM data) to detect deforestation in protected area and assess how significant these deforested area in comparison to the overall forest land in the study site. More over, an attempt was made to find if any relationship between a sustainably managed forests and spectral radiance is exist.


Table 1 Selected ecological criteria, indicators and verifiers

Criterion Indicator Selected Verifiers
Stability of ecosystem E 1.3 The intensity of damage in the protected areas which includes the danger of forest fires -Size and type of damaged protected area.-Condition of damaged protected area
E 1.4* Condition of tree species diversity in protected area in various forest formations/types within management units -Tree species diversity in virgin (unlogged forest)-Tree species diversity in logged over area-Tree species diversity in protected area.
*This indicator and its associated verifiers have been modified to cover “tree species diversity” instead of “flora and fauna diversity” in order to fit them within the scope of this work.

The use of Remote Sensing and GIS to Support Sustainable Management of Tropical Forest in East Kalimantan, Indonesia


Study Area, Materials and Methods

Labanan concession area is found in Berau regency, East Kalimantan, Indonesia. This province is located in the eastern Indonesian part of the island of Borneo. It lies west of the Kelai river. The entire concession area covers about 83,240 ha of which 54, 567 ha is under fixed production, 26,997 ha under limited production and 1676 ha has been left for other uses such as transmigration, camping (by the logging and cruising crew), settlement and agriculture (Fakul tas Kehutanan, 2000). The concession area is managed by P.T. Inhutani I, which is a government owned concession company. The natural vegetation of East Kalimantan is dominated by lowland mixed dipterocarp forest. Dipterocarps represent 50% of basal area and 60% of stand volume. The Berau area is characterized by high botanical diversity of the tree species. Large parts of natural forest in East Kalimantan have been logged.

Two images Landsat-7 ETM+ acquired on 26th August 2000 and Landsat-5 TM acquired on 12th April 1996 were used in this research. The methodology flowchart (Figure 1) explain the general methodology and approach used in this research.



Figure 1 Flowchart of the Research Methodology

According to the Indonesian national forest management guidelines an average of 8 trees per hectare are felled at 35-year interval. The forest management unit has been divided into seven five-year working plan areas called RKL (Rencana Karya Limatahun) in local Indonesian language. Thus, the forest concession land in this area divided into 7 RKLs. Each RKL divided into 5 years felling plan. By the end of the felling cycle (35 years rotation) the logging company will start logging again in RKL 1 which was logged 35 years earlier.


Results and Discussions


Assessment of damage within the river and other protected area

This sub-chapter demonstrates the possibility of using remote sensing techniques, to assess damage within the river-protected area, and then relates this assessment with the intensity scale of indicators for Sustainable Natural Production Forest Management. Damage within the river-protected area was considered because the rest of the protected area to the south of the concession has not suffered any degradation, deforestation or observable change, which means it is still intact. This can be evidenced by the colour composites of Landsat TM 1996 and 2000, with the Middle Infrared, Near Infrared and Green bands in the Red, Green and Blue channels respectively. This colour composite gives a clear picture of the terrain properties of the southern protected area, which is rugged. Mutuagung Lestari, the certification body accredited by LEI, also reported no evidence of severe damage within the southern protected area.

The use of Remote Sensing and GIS to Support Sustainable Management of Tropical Forest in East Kalimantan, Indonesia


Delineation of areas of damage

Two Landsat TM images acquired in 1996 and 2000 were used in damage assessment, by which areas of encroachment around the river-protected area were delineated in each image using visual interpretation. An example of such delineated area from Landsat TM 2000 using the 542-color composite is shown in Figure 2, 3 and 4. These areas were later polygonized and then rasterized. The encroached areas were derived from summing up the areas of all the pixels. The resulting sizes of encroached areas (within the protected area) for the years 1996 and 2000 are shown in Table 2. The proportion of protected area encroached in each of the years 1996 and 2000, was computed by expressing each of the encroached areas in hectares for 1996 and 2000, as a percentage of the total protected area given in Table 2.


Table 2 Showing the size of encroached area in 1996 and 2000 within the river protected area

Year Encroached area (Ha) Total river protected area Area encroached expressed as a percentage of total protected area
1996 22 1144 1.92% 2000 86 1144 7.52%



Figure 2 An example of digitised encroachment area around the river (In the year 2000)



Figure 3 Map showing encroachment areas around the river-protected area in Labanan concession in the year 1996



Figure 4 Map showing encroachment areas around the river-protected areas in Labanan concession in the year 2000

According to the intensity scale rating associated with indicator E 1.3 i.e. “the intensity of damage in the protected areas which includes the danger of forest fires”, the ranking for this particular indicator, with regard to encroachment within the river-protected area, is “GOOD”. This is because as specified in the scale, the area size of the damaged protected area is small (