Logged-over Forest Research Articles

Litter Fall in A Primary and Two Logged-over Lowland Tropical Rainforests in Pasirmayang, Jambi.

Litter accumulation in a primary and a logged-over lowland dipterocarp forest at Pasirmayang, Jambi was measured using the litter trap method. In the primary forest, traps were placed in four distinct areas, reflecting the succession stages of the forest from building to maturation. In the logged-over forest, litter production was measured at two different sites, one cut in 1979/1980 and the second in 1983/1984. In the primary forest, average litter production during the observation period was 925 g m"2yr'. In the logged-over forest, average litter production was 721 g m'2 yr1 for the site cut in 1979/1980 and 706 g m'2 yr1 for the site cut in 1983/1984. Leaves comprised the major contributor of litter with 67% of total litter produced in the primary forest, 67% of total litter in the 1979/1980 cut logged-over forest, and 65% of total litter in the 1983/1984 cut logged-over forest. The purpose of the study was to use litter fall as a measure of forest productivity to assess the recovery of logged-over forests and, to provide a basis for comparison of forest-derived land practices for appropriate forest management strategies. Key words: Litter production/primary forest/logged-over forest/forest productivity/Pasirmayang/Jambi.

SPECTRAL AND TEXTURAL CHARACTERISTICS OF THE LOWLAND TROPICAL RAIN FOREST OF JAMBI, SUMATERA

Analyses of Landsat TM and SPOT multispectral data were performed with a very detailed description of the vegetation cover in the field to get a relevancy and consistency of digital image classification in a semi-automatic approach. Three main vegetation types, i.e. primary forest, logged-over forest and secondary forest after clear cut were analyzed and the microclimatic parameters were also measured to describe the ecological condition of the vegetation. Spectral and textural analysis of data obtained from field measurements and spectral reflectance values of the remote sensing data are the main topic of this report as one aspect of study on the Digital Method of Detection and Monitoring on Forest Ecosystem Change Using High Resolution Satellite Data funded by the Indonesian National Research Council. This study shows that spectral reflectance values alone cannot differentiate the logged-over forest from the primary forest, but it is very sharply distinguished from the secondary forest. As for the texture analysis, it is possible to distinguish the logged-over forest from the primary forest, as shown by different values of degree of Entropy, although spatially, it is still doubtful. Key words: Indonesia/Jambi/Tropical rain forests/lowland areas/Remote sensing/Vegetation Analysis/ Logged-over forests/Primary forests/Secondary forests.

Potential of Airborne Radar To Support the Assessment of Land Cover in a Tropical Rain Forest Environment

The potential of airborne radar systems as tools for collecting information in support of the assessment of tropical primary forests and derived cover types was examined. SAR systems operating with high spatial resolutions and different wavelengths (i.e., X-, C-, L- and P-band) acquired data in Guyana and Colombia. Three fundamentally different information sources from the radar return signal were considered in the study: its strength or backscatter, polarization and phase, and spatial variability or texture. Radiometric, polarimetric, and textural attributes were computed from predefined image regions selected to represent five types of primary forest, selectively logged forest, secondary forest, and a mixture of nonforest cover types. Texture was found to be the most important source of information in high resolution X- and C-band images. Textural attributes computed per region made modest to good bases for automated classifications of the land cover types studied. Primary forests and logged-over forests were found to display particularly distinctive textural patterns. Backscatter values computed per region from L- and P-band radar images also made modest to good classification bases. Backscatter measurements in either a single L- or P-band channel enabled accurate classification of nonforest cover types. Reliable identification of secondary forests and logged-over forests generally asked for measurements in a minimum of two C-, L-, and/or P-band radar channels. Similarly, reliable assessment of primary forest types required observations in a minimum of three C-, L-, and/or P-band radar channels.

Effect of gap liberation on the performance and growth of dipterocarp trees in a logged-over rainforest

Large parts of southeast Asian dipterocarp rainforests have been overlogged by applying different systems of selective cutting. Logged-over forests are expected to re-establish the original dipterocarp stock through natural regeneration. Post-logging silvicultural operations, notably crown liberation and enrichment planting, are conducted to ensure sustained yield. These techniques have largely failed to achieve the desired goal. We tested the effect of gap liberation on the performance and growth of dipterocarp trees in an overlogged concession area in south Kalimantan, Indonesia. Twelve gaps, 500–1600 m 2 in size, were sampled based on the occurrence of ephemeral dipterocarp seedling stock (notably Shorea spp.) under the canopy. Six gaps were opened up 6 years after the logging and inventoried, together with the untreated gaps, 12 years after the logging. In liberated gaps, dipterocarps accounted for 77% of the total basal area, compared with 20% in the untreated area. Survival of dipterocarps was 33% higher and diameter twice as high in liberated gaps as in the untreated plots. In height, no significant difference was detected. Liberation also improved the quality of dipterocarp trees in terms of stem and crown form. The volume of red meranti ( Shorea spp.) in liberated gaps was 90 m 3 compared with 36 m 3 in the untreated area. Gap liberation was proved as a silviculturally and economically feasible management alternative of overlogged dipterocarp rainforests.

Growth of dipterocarp seedlings in artificial gaps: An experiment in a logged-over rainforest in South Kalimantan, Indonesia

The objective of the study was to assess the feasibility of assisted natural regeneration of dipterocarp rainforest trees through gap simulation. Three hypotheses were tested: (1) opening of a gap enhances the rate of growth of dipterocarp seedlings; (2) growth of dipterocarp seedlings depends on gap size, being fastest in relatively small openings; and (3) growth of dipterocarp seedlings depends on gap size independently of the species concerned. Five gaps ranging from 406 m 2 to 1242 m 2 were opened up randomly in a logged-over dipterocarp forest in South Kalimantan, Indonesia, in October 1987. The measurements were carried out in October 1993, 6 years after gap establishment. A systematic line sampling survey in the surrounding forest was carried out in June 1994. Height and diameter at breast height were measured from all trees greater than 5 cm in diameter. On the basis of hypothesis testing it was concluded: (1) Diameter frequency distributions of gaps differed significantly from those of the surrounding forest area indicating that dipterocarps commence fast growth after the opening up of the gap. (2) Optimal gap size was under 500 m 2. (3) Shorea parvifolia grew faster than S. fallax in gaps, and the growth in both species was negatively correlated to gap area. The results suggest that the optimal light conditions for fastest early growth of dipterocarps can be achieved by opening up gaps of less than 500 m 2 in logged-over forests. If such gaps are opened up in places with an abundant ephemeral seedling stock of dipterocarps, this will allow more concentrated and, hence, cost-effective silvicultural operations. Gap simulation will also reduce the need for unnecessary treatment of the forest between gaps and thereby sustain the natural mosaic structure of the forests.

Population dynamics of tree seedlings in a mixed dipterocarp rainforest before and after logging and crown liberation

Southeast Asian dipterocarp rainforests have largely turned into secondary forests due to heavy, repeated selective loggings. Secondary forests are expected to re-establish the original primary forest composition through natural succession. Post-logging silvicultural operations, especially liberation cutting of the pioneer/secondary forest trees, are conducted in order to enhance this succession. These techniques may not achieve the desired goal. We studied the structure and development of seedling stock of three stands of mixed dipterocarp forest type in southern Borneo, including (I) a stand logged over 12 years ago and treated by crown liberation 5 years later, (II) an untreated logged-over stand, and (III) an unlogged, untreated stand, over a period of 2 years. We found no indication that succession of the seedling stock in logged-over forests would take any directed course towards the species composition of the unlogged control area within long (12 years) or short (2 years) periods. Seedling density of logged-over stands was markedly higher than that of the unlogged area. Within 12 years, pioneer species were almost totally eliminated from the seedling stock of the untreated area, but to a lesser extent than that of the treated one. Dipterocarp seedlings were most abundant in the untreated logged-over stand. Crown liberation appeared to favour the recruitment of the seedlings of light-demanding pioneer species, instead of enhancing the regrowth of dipterocarp timber stock.

Simulation of multi-species tropical forest dynamics using a vertically and horizontally structured model

The mutual interaction of forest growth and light conditions causes vertical and horizontal differentiation in the natural forest mosaic. The associated physical processes should be represented in simulation models describing long-term forest dynamics. The FORMIX2 (tropical) forest simulator incorporates the multi-storey canopy layer structure of the natural tropical forest, the basic processes of gap succession dynamics and gap interaction by tree fall and seed dispersal, several functionally different species groups (emergents, main canopy trees, pioneers, woody treelets and forest-floor herbs) and the energy (carbon) balance of assimilation, dissimilation, and increment resulting from the differing light conditions for the various canopy layers in the gap-size areas of a forest mosaic. The vertically and horizontally structured FORMIX2 model produces time-dependent results (average per hectare data) for stem numbers, diameter distributions, basal areas, standing crop and yield, as well as dynamic views of the forest profile and of spatial forest development, as a function of logging method and intensity and silvicultural treatment. The model has been applied in an exploratory investigation to compute the long-term development of (a) virgin forest and (b) logged-over forest in Sabah, using prototypical data. The results obtained agree with empirical data.

A management planning concept for sustained yield of tropical forests in Sabah, Malaysia

The paper presents a forest management planning concept presently under development at the Forestry Department of the State of Sabah, Malaysia. This planning procedure forms part of a comprehensive forest management system directed towards the sustainable production of timber and other produce in the commercial dipterocarp forests which over an area of about 2.5 million ha, or approximately 40% of the total landmass of the State. In order to ensure application of this system, different field techniques are presently tested in an area of 55 000 ha logged-over forests (Deramakot Forest Reserve). The planning procedure is an amalgamation of methods successfully applied for sustained yield management in many other parts of the world and consists of a combination of enterprise-level and compartment-level management planning, the latter being a component which so far has not been applied in Sabah. This procedure is aimed at serving the forestry sector in Sabah as a tool to facilitate the changeover from pure exploitation of the forest to sustainable practices.

An Approach Towards Multiple-use Forest Management of Logged-over Forests in Sabah

An Approach Towards Multiple-use Forest Management of Logged-over Forests in Sabah

Plant diversity and energy potency of community forestin East Kalimantan, Indonesia: Searching for fast growing wood species for energy production

Abstract. Amirta R, Yuliansyah, Angi EM, Ananto BR, Setiyono B, Haqiqi MT, Septiana HA, Lodong M, Oktavianto RN. 2016. Plant diversity and energy potency of community forest in East Kalimantan, Indonesia: Searching for fast-growing wood species for energy production. Nusantara Bioscience 8: 22-30. Nowadays, there is an increasing interest in intensifying the production and use of biomass to replace fossil fuels for the production of heat and electricity, especially for a remote area that generally abundance with the wood biomass resources including in East Kalimantan, Indonesia. In this work, diversity of plant species that commonly grows in community forest area of East Kutai District, East Kalimantan, Indonesia had been studied to point out their energy potency to be used as biomass feedstock for the electricity generated. Diversity of plant species in the community forest was evaluated by making 13 sampling plots with 20mx20m size approximately. Concurrently, the energy properties of plant biomass such as proximate and ultimate compositions were also analyzed using ASTM methods. Results showed that more than 30 species of tropical trees and wood shrubs were grown in the community forest. The presence of them was classified into two different growths of origins: natural and artificial plantation, and also three different categories of plant resources: tree species from logged-over forest, commercial fast-growing plant tree species for the fiber production and wood shrubs. The highest dominancy and productivity was found in Paraserianthes falcataria (L.) Nielsen since the wood biomass was artificially planted for commercial purposes. Among the 31 plant species analyzed we found the highest energy potency was obtained from Cratoxylum cochinchinense (Lour.) Blume that produced 3.17 MWh/ton, and the lowest was from Trema orientalis (L.) Blume 0.97 MWh/ton. The wood shrubs species such as Vernonia amygdalina Delile., Piper aduncum L., Gliricidia sepium (Jacq.) Kunth ex Walp., Calliandra calothyrsus Meissner., Bridelia tomentosa Blume, Vitex pinnata L., Vernonia arborea Buch.-Ham. and Bauhinia purpurea var. corneri de Wit. were suitable to be used as sustainable feedstocks for the electricity generated and promising to be developed as energy plant species in the future using Short Rotation Coppice system (SRC).