Logged-over Areas Research Articles

An alternative Silvicultural approach in managing logged-over forests

Based on the reality of production forest management so far, logged-over forest improvement activities generally have received less attention, giving rise to the notion that the management of logged-over areas is not being taken seriously. In general, regeneration and maintenance of remaining stands as a component of the silvicultural system has not been carried out. Silviculturists must address these developments and respond to rapidly changing expectations and global paradigm shifts in how forests are viewed. Silviculturists are challenged to develop silvicultural practices, including silvicultural systems that support the function and dynamics of forest ecosystems, and maintain biodiversity and ecosystem resilience while providing needed wood and non-timber products. In the context of production forest management, the adaptation differences of commercially valuable species in terms of their position in the natural vegetation development stage can be used as a consideration in the development of silvicultural system determination. Thus, the choice of silvicultural system to be applied reflects the condition of the forest. Alternative silvicultural approaches are characterized by several aspects, including selective cutting, diversity, and combination of mixed species with natural regeneration, and avoidance of intensive site-preparation methods.

Above ground biomass after 39 years logging in Kintap Research Forest, South Kalimantan

Land degradation causes the fragmentation of forest areas. The fragmentation can be in the form of a decrease in species diversity and carbon storage in an area including logged-over areas. This study aims to obtain stand abundance, basal area, and potential of above ground biomass that can be used in estimating natural recovery in logged-over areas. Stand measurements were carried out in 3 different areas with the distance of the plot from the road as a differentiating factor. The measurement parameters include tree species, diameter, and tree height with the smallest diameter being 10 cm. Making plots at each location covering an area of 1 ha with an observation sub-plot measuring 20 m x 20 m (400 m2). Estimation of carbon storage used the allometric model compiled by Brown, Ketterings, and Basuki. The results showed that the biomass potential reached 190 tones/hectares – 290 tones/hectares. This potential is mostly contributed by trees with a diameter of more than 20 cm. Trees with a diameter of 20 cm accounted for more than 50% of the total biomass. This condition indicates that silvicultural technique in the form of maintaining the remaining stands after felling are very necessary for accelerating the growth of small-diameter trees so that natural succession can occur more quickly.

TINGKAT KERUSAKAN TEGAKAN TINGGAL PADA AREAL BEKAS TEBANGAN DI IUPHHK-HA PT GUNUNG MERANTI, PROVINSI KALIMANTAN TENGAH

Timber harvesting activities in forest concession using the Indonesia Selective Cutting and Planting silvicultural (ISCP) system can cause damage to residual trees. The greater the damage of residual trees to be indicator the less effective the activity. This study aims to determine the damage of residual trees caused by harvesting in the logged-over areas using the ISCP silvicultural system. The study used a research plot measuring 40 m x 240 m (0.96 ha) with 5 replications. Each research plot was consisted of 24 sub plots each for the trees, pole, sapling and seedling levels. Sample felled trees were determined as many as 30 trees. The results showed that the average damage caused by harvesting of 1 tree was 6.46 seedlings/ha; 7.17 saplings/ha; 2.13 poles/ha and 2.25 trees/ha. In general, the damage to residual trees due to felling was 11.28% for seedlings; 11.56% for saplings, 12.14% for poles and 11.8% for trees. The level of damage to seedlings, saplings and poles were in the medium category, while the level of damage to the tree level was in the low category. Keywords: Damage, harvesting, residual trees, silvicultural system

Is it possible that logged-over areas can recover naturally: the case of logged-over areas in South Kalimantan

Logging causes a decline in the quality of stands in all forest types. However, these forests can recover naturally. This study aims to measure the ability to recover logged-over areas based on the species composition and above-ground biomass. This research was conducted by logged-over forest in 1987, of lowland forest type in the Kintap Research Forest, South Kalimantan. The research was carried out by making a measurement plot on three types of land with the main road’s distance as a differentiating factor. Each type of measurement plot measuring 1 hectare is divided into five replications with 20 m × 100 m. The measurement parameters are the diversity of species and above-ground biomass estimated by the allometric model. The results showed that the distance difference did not affect the species composition and the potential for above-ground ground biomass. The species composition is indicated by the diversity index, evenness index, and dominance index, including above-ground biomass. Overall, more than 100 tree species present after felling and an evenness index of higher than 0.75, indicating that the community is stable with high species diversity and low dominance. This indicates that logged-over areas can recover but that recovery requires adequate regeneration after logging. The implication is that logging must leave enough standing stands. This condition will encourage natural regeneration or succession in logged-over forests.

Study of Light Intensity in Riparian Zone of Teak Production Forest in KHDTK Cemoro Modang

Vegetation is one of the factors that influence the protection function of the riparian zone. Riparian vegetation in teak production forests is dominated by teak plantation with low species diversity. Rehabilitation is needed to increase the role of vegetation in protecting riparian zone. Data and information of light intensity is required to support the success of rehabilitation. Light intensity is a significant factor for photosynthesis which impacts on the survival, growth and adaptation of a vegetation. The varying light intensity in the riparian zone due to diverse land cover becomes a challenge in rehabilitating this area. This study aims to identify light intensity in riparian zone of Modang River and Cemoro River in the teak production forest. Recognizing light characteristics will help in species selection to rehabilitate this area. Primary and secondary data were used in this study. Direct measurement of light intensity was carried out along riparian zone of the Modang and Cemoro Rivers by systematic sampling. A sampling plot measuring 20 x 20 meter was used as the location of the sampling point with a total of 36 plots. Climate data are obtained from field observations through the nearest climatology station. The results showed that different canopy cover causing light intensity of Modang and Cemoro rivers varies. Canopy cover in this area can be divided into canopy cover of teak forest of various ages (production plants), johar (previous rehabilitation plants), and logged-over areas. The selection of tolerant and intolerant trees is important to use as consideration for rehabilitation, in addition to other silvicultural and socio-economic considerations of the local community.

Study of Light Intensity in Riparian Zone of Teak Production Forest in KHDTK Cemoro Modang

Vegetation is one of the factors that influence the protection function of the riparian zone. Riparian vegetation in teak production forests is dominated by teak plantation with low species diversity. Rehabilitation is needed to increase the role of vegetation in protecting riparian zone. Data and information of light intensity is required to support the success of rehabilitation. Light intensity is a significant factor for photosynthesis which impacts on the survival, growth and adaptation of a vegetation. The varying light intensity in the riparian zone due to diverse land cover becomes a challenge in rehabilitating this area. This study aims to identify light intensity in riparian zone of Modang River and Cemoro River in the teak production forest. Recognizing light characteristics will help in species selection to rehabilitate this area. Primary and secondary data were used in this study. Direct measurement of light intensity was carried out along riparian zone of the Modang and Cemoro Rivers by systematic sampling. A sampling plot measuring 20 x 20 meter was used as the location of the sampling point with a total of 36 plots. Climate data are obtained from field observations through the nearest climatology station. The results showed that different canopy cover causing light intensity of Modang and Cemoro rivers varies. Canopy cover in this area can be divided into canopy cover of teak forest of various ages (production plants), johar (previous rehabilitation plants), and logged-over areas. The selection of tolerant and intolerant trees is important to use as consideration for rehabilitation, in addition to other silvicultural and socio-economic considerations of the local community. Keywords: light, riparian, teak production forest

Litter Production of Logged-over Forest using Indonesia Selective Cutting System and Strip Planting (TPTJ) at PT. Sari Bumi Kusuma

Enrichment is a planting activity in logged-over areas with less natural regeneration of commercial species. Enrichment planting on Indonesian Silvicultural System of Selective Cutting and Strip Planting (TPTJ) aims to increase the productivity of logged-over areas (LOA) using Strip Plantation System. Strip Planting System is an intensive management system attempted by opening logged-over area for strip planting and planting purposed species. Plantation in Strip Plantation System needs much nutrition for its growth. Nutrition returning through litter on TPTJsystem was essentially notified. This research aims to identify litter production in strip planting and on-strip planting at logged-over areas, within one year, five years, ten years after logging, andprimary forest at PT. Sari BumiKusuma. This research was conducted from September 2010 to February 2011. The litter trap was used to calculate litter accumulation.Litter production at LOA after one year of planting is 2.27 ton.ha-1.6 months-1in strip planting and 3.68 ton.ha-1.6 months-1in non-strip planting; litter production at LOA after five years is 4.97 ton.ha-1.6 months-1in strip planting and 4.98 ton.ha-1.6 months-1in non-strip planting; while litter production at LOA after ten years is 4.03 ton.ha-1.6 months-1in strip planting and 4.67 ton.ha-1.6 months-1in non-strip planting. Using Selective Cutting and Strip Planting System (TPTJ), it is found that litter production in strip planting was not significantly different from that in non-strip planting, and that the litter production is recovered after 5 years.

Designing intergovernmental fiscal transfers for conservation: The case of REDD+ revenue distribution to local governments in Indonesia

A REDD+ scheme would involve the transfer of financial resources to forested developing countries taking part in it. This paper simulates different approaches to the design of intergovernmental fiscal transfers (IFTs), a possible means to channel a REDD+ international payment to local governments which, in several countries, have a certain degree of authority over forest management. Using Indonesia as a case study, the cost-reimbursement and the derivation approaches are tested. It is demonstrated that both approaches could be used. Using the cost-reimbursement approach, localities with more degraded forests would receive a higher compensation per unit of carbon emission reduction than districts with primary forests. Avoiding further conversion of logged-over areas is associated with higher opportunity costs when compared with preventing the conversion of primary forests. In contrast, the derivation approach sets a fixed percentage and rate to distribute REDD+ revenues and ignores the opportunity costs of REDD+ incurred by local governments. The distribution of REDD+ revenues to eligible local governments is based on an assumed market price of carbon credits from REDD+. This paper concludes by discussing the implications of the findings for designing the distribution of REDD+ revenues, both for Indonesia and more generically for other developing countries.

Integrated Landsat Image Analysis and Hydrologic Modeling to Detect Impacts of 25-Year Land-Cover Change on Surface Runoff in a Philippine Watershed

Landsat MSS and ETM+ images were analyzed to detect 25-year land-cover change (1976–2001) in the critical Taguibo Watershed in Mindanao Island, Southern Philippines. This watershed has experienced historical modifications of its land-cover due to the presence of logging industries in the 1950s, and continuous deforestation due to illegal logging and slash-and-burn agriculture in the present time. To estimate the impacts of land-cover change on watershed runoff, land-cover information derived from the Landsat images was utilized to parameterize a GIS-based hydrologic model. The model was then calibrated with field-measured discharge data and used to simulate the responses of the watershed in its year 2001 and year 1976 land-cover conditions. The availability of land-cover information on the most recent state of the watershed from the Landsat ETM+ image made it possible to locate areas for rehabilitation such as barren and logged-over areas. We then created a “rehabilitated” land-cover condition map of the watershed (re-forestation of logged-over areas and agro-forestation of barren areas) and used it to parameterize the model and predict the runoff responses of the watershed. Model results showed that changes in land-cover from 1976 to 2001 were directly related to the significant increase in surface runoff. Runoff predictions showed that a full rehabilitation of the watershed, especially in barren and logged-over areas, will be likely to reduce the generation of a huge volume of runoff during rainfall events. The results of this study have demonstrated the usefulness of multi-temporal Landsat images in detecting land-cover change, in identifying areas for rehabilitation, and in evaluating rehabilitation strategies for management of tropical watersheds through its use in hydrologic modeling.

Avifaunal Diversity in Bulosao Watershed Forest Reserve Lawaan, Eastern Samar, Philippines

Bulosao Watershed Forest Reserve is regarded as one of the most important areas in terms of biodiversity in the island of Samar and within the greater Mindanao faunal region. Four study sites representing different habitat types, elevation range and degree of human disturbance were surveyed for their faunal composition. Standard faunal survey methods such as transect survey was used during the entire duration of the study. The methods were augmented with observations and ethnobiological interviews. A total of 41 species of birds belonging to 12 orders, 25 families and 35 genera were recorded. Of these, twelve (29%) are endemic to the Philippines and one to the greater Mindanao faunal region. Among avian species, sixteen (40%) are considered threatened or at risk. Major threats birds and other wildlife populations in the reserve include hunting and habitat alteration. Hunting among the local community is not only for subsistence but also for commercial purposes. Major activities leading to habitat destruction include conversion of logged-over areas into cultivation, illegal logging and indiscriminate collection of other forest products.

Land use change and population growth in the Morobe Province of Papua New Guinea between 1975 and 2000

The relation between human population growth and land use change is much debated. Here we present a case study from Papua New Guinea where the population has increased from 2.3 million in 1975 to 5.2 million in 2000. Since 85% of the population relies on subsistence agriculture, population growth affects agricultural land use. We assessed land use change in the Morobe province (33,933 km 2) using topographic maps of 1975 and Landsat TM images of 1990 and 2000. Between 1975 and 2000, agricultural land use increased by 58% and population grew by 99%. Most new agricultural land was taken from primary forest and the forest area decreased from 9.8 ha person −1 in 1975 to 4.4 ha person −1 in 2000. Total population change and total land use change were strongly correlated. Most of the agricultural land use change occurred on Inceptisols in areas with high rainfall (>2500 mm year −1) on moderate to very steep slopes (10–56%). Agricultural land use changes in logged-over areas were in the vicinity of populated places (villages), and in close proximity to road access. There was considerable variation between the districts but districts with higher population growth also had larger increases in agricultural areas. It is concluded that in the absence of improved farming systems the current trend of increased agriculture with rapid population growth is likely to continue.

Sustainable Forest Management in Tropical Rain Forests

In planning of sustainable forest management, economic, environmental and social demands often conflict. Forest management in Southeast Asian tropical dipterocarp forests has been particularly biased towards maximizing immediate economic return from extensive logging. Overexploitation and other forms of uncontrolled land use within these forests have led to the situation where the remaining natural forests, most of them in Indonesia, will be liquidated within the next 10-15 years at the current rate of deforestation. In this paper we present an approach for sustainable forest management planning in which economic, environmental and social sustainability are considered simultaneously in order to define an optimal management strategy from a set of available alternatives. We carried out a case study within a rain forest logging concession in Indonesian Borneo by using a participatory planning approach involving interviews of the local people, environmental assessment and economic analyses. We used the Analytic Hierarchy Process (AHP) method for resource allocation and priority setting in order to identify an optimal strategy which yields a sustained economic output from timber production, while at the same time being environmentally and socioculturally sustainable. Despite their relatively high costs, strategies involving selective harvesting combined to complete restoration of original dipterocarp stock in logged-over areas were superior in terms of economic, environmental and social sustainability. Priorities set by local communities for the strategies to meet their socioeconomic and cultural needs coincide well with those ensuring the restoration and biodiversity.

Working Time Design for Industrial Forest Plantations in East Kalimantan

The objectives of this study were to clarify physiological loads under tropical conditions and to establish a proper working time design for tropical forestry operations. The research was conducted in East Kalimantan, Indonesia, in 1995. In this research, physiological loads and thermal conditions were investigated under various conditions, i.e., in forests and nurseries, on roads and at logged-over areas. Using the standards of the American Conference of Governmental Industrial Hygienists (ACGIH), a structure of work to rest proportions could be designed properly. Results showed that felling and cutting trees and weeding in the forest could be done continuously early in the morning and with 25% rest time for the remainder of the work day. Spreading fertilizer at the nursery could be done almost continuously all day. Road maintenance could be performed continuously during early morning but 50–100% rest time was needed for the remainder of the day. At logged-over areas, path clearing using chainsaws and soil hoeing required 50% rest early in the morning and 75–100% rest after that time, while planting required 25% rest early in the morning and 50–100% rest after that time. In conclusion, work done at logged-over areas required a greater percentage of rest time than work at other locations except early in the morning.

The role of exotic conifer plantations in rehabilitating degraded tropical forest lands: A case study from the Kibale Forest in Uganda

Exotic softwood plantations were introduced into the Kibale Forest of western Uganda in the 1960s and early 1970s to convert grassland areas into wood fiber producing sites. Following establishment, few silvicultural activities were initiated within these plantings, and today harvesting operations are planned to remove these over-stocked stands to allow for the development of natural forest communities. During the period May–September, 1994, we inventoried the overstorey and advanced regeneration in plantations of Pinus caribeae and Cupressus lusitanica. Within 92 randomly located 0.01 ha plots per plantation type, we measured the height and diameter of all stems encountered. The pines supported approximately 1.5 times the density and diversity of native woody stems found beneath the cypress (3424 tree and shrub stems ha −1 under the pines), while the pines themselves were characterized by stocking levels, mean heights, and canopy closures which were higher than those of the cypress. We suggest that the greater natural regeneration development observed beneath the pines, when compared with the cypress, is a function of pine development (influence upon competition) and stem characteristics (influence upon seed dispersal mechanisms). We then compared our regeneration observations with those reported for unlogged and logged areas of the surrounding natural forest. Within the sapling class (diameter at breast height (dbh) less than 5 cm), which accounted for the majority of the advanced regeneration under the softwoods, the plantations failed to support the same density of tree-species stems as found in the natural forest (3077 stems ha −1 vs. 2177 and 1111 under the pines and cypress, respectively). The number of stems ha −1 in the pines approximated those in 25-year-old logged-over areas of the natural forest. Species richness beneath the conifers appears to approach the number found in the surrounding forest; however, a closer look at the species composition suggest several deficiencies in the composition of the advanced regeneration beneath the plantations (especially within the commercial class). Following 25 years of development, the advanced regeneration beneath the plantations (especially the cypress stands) is relatively impoverished compared to the levels of tree diversity and stocking characteristic of both unlogged and logged natural forest sites. The conditions beneath the pines however, suggest that a diverse community of native species may eventually exploit this environment through time. The dominance of the fast-growing, light-canopied, N 2-fixing Albizia and Milletia genera, could help to nurture the further development of a well-structured, well-represented secondary forest through time. With the application of silvicultural treatments, there may be management opportunities to further enrich the quality of the advanced regeneration beneath softwood plantations. We explore future areas of research that could contribute to this end.

Effect of vegetative competition on regeneration of white spruce

The rate of invasion and height growth of vegetation in logged-over areas were studied on four forest site types in the white spruce – alpine fir (Piceaglauca (Moench) Voss – Abieslasiocarpa (Hook.) Nutt.) forests north of Prince George, B.C. On Cornus–Moss, Aralia–Dryopteris, and Devil's Club site types, which generally had full stocking, vegetation that grew under the canopy of trees was replaced after logging by aggressive pioneer species. Annuals were the first to invade the logged-over area, followed by biennials and perennials. The invasion of shrubs was the slowest. After logging, 6 or 7 years elapsed before vegetation became a serious hindrance to regeneration and, by that time, white spruce seedlings planted immediately after logging were tall enough to withstand competition. On the Alluvium site type, where stocking is usually open and shrubs and grasses that thrive in the logged-over areas are present, spruce seedlings were overtopped during the first growing season and eliminated as the density of shrubs increased.

Bird diversity in six habitat types of PT Inhutani I Labanan, East Kalimantan

Birds can be used indirectly or directly as a bioindicator of environment. Birds species living in six habitat types of PTInhutani I Labanan Kalimantan Timur (namely, logged-over areas that has been exploited in 1976/1981 and 1981/1986,forested area that is being exploited in 1999/2000, primary forest that will be exploited in 2001/2002, Labanan Jaya Villageinhabited in 1982/1983, and Segah-Malinau Transmigration Settlement inhabited in 1997/1998) were recorded with transectmethod (long of 3 km and within sighting distance of 25-50 m) at 06.30-10.00 and 15.00-17.30 in both dry and rainy seasons. One hundred and two identified species belonging to 34 families and 6 unidentified species were found. Habitat types and seasons affect bird diversity (the number of species and abundance). Percent dissimilarity of birds between habitats ranged 0,53-0,95 in rainy season and 0,54-0,95 in dry season and between seasons ranged 0,50-0,80. Quantitative values have to be completed with qualitative consideration to assess habitat condition or changes.© 2003 Jurusan Biologi FMIPA UNS SurakartaKey words: bird diversity, forest, urban area, habitat condition.

Geology and Petroleum Possibilities of the Olympic Peninsula, Washington

The Olympic Peninsula is located in the extreme northwestern part of the United States. Extensive forests, logged-over areas, glacial deposits, and scarcity of roads hinder geological investigation. The geological column is limited to the Oligocene, Miocene, Pleistocene, and possibly Eocene. Much superficial folding and faulting occur along the coast. In the lower shale member of the Miocene, there are many gas and two oil seeps. The oil possibilities are worthy of investigation and test wells are proposed.