Dryland Forest Research Articles

Tipologi penggunaan dan perubahan lahan berbasis spasial: pendekatan studi kasus di kabupaten jayapura

Jayapura Regency is an area in Papua Province with relatively rapid growth since it was formed into a district in 2016. Over the last ten years, massive land use and changes have occurred in Jayapura Regency. Changes in land use can be identified by looking at the land use that occurred in the past and present. Land use change is an unavoidable process, so it is important to study it empirically and in multi-time observations for development planning. In this regard, the formulation of the problem is that the types of land use and change in Jayapura Regency are not yet known with a case study of the spatial approach in 2005 and 2018. Based on the formulation of the problem, the purpose of this study is to determine the typology of land use and change in Jayapura Regency for 2005 and 2018. It is hoped that this study will become a data base and spatial information on land use in Jayapura Regency and enrich knowledge about spatial models of land use change that can be used as an approach to regional development planning. The results of the study show that based on land use classification in Jayapura Regency, there are 20 typologies of land use where primary dry land forest type has an area of ​​983,713.71 ha or 67.98% of the total area. Most of these forests are state forest areas with protection and production functions. During the period 2005 – 2018, Jayapura Regency lost 6,508.08 ha of forested area with an average rate of forest depreciation reaching more than 500.62 ha annually, while open land changed functions almost half of its original use.

Land cover change impact analysis: an integration of remote sensing, GIS and DPSIR framework to deal with degraded land in Lepan Watershed, North Sumatra, Indonesia

Abstract. Rahmawaty, Rauf, A, Harahap MM, Kurniwan H. 2022. Land cover change impact analysis: an integration of remote sensing, GIS and DPSIR framework to deal with degraded land in Lepan Watershed, North Sumatra, Indonesia. Biodiversitas 23: 3000-3011. The Lepan Watershed is located in North Sumatra Province, Indonesia. The types of land cover in the Lepan Watershed were examined to analyze the impact of changes in land cover over periods of five years and ten years (2009-2014-2019). This study used three analyses: analysis of land cover type, land cover change, causes and impacts of those changes, and government responses to those changes. Analysis of land cover types and changes was conducted using geographic information system (GIS). The land cover change impacts were analyzed using the driving forces, pressure, state, impact, and response (DPSIR) approach. Twelve land cover types were identified, i.e., water body, dryland forest, industry, mixed garden, open land, mangrove, rubber plantation, oil palm plantation, settlement, paddy field, shrub, and pond. For five years, changes in land cover occurred in the Lepan Watershed. During ten years (2009-2019), the mixed garden, oil palm plantation, and settlement increased, while dryland forest, mangrove, rubber plantation, paddy field, shrub, and pond decreased. The water body and industry land cover types did not undergo extensive changes over the past five and ten years. Changes in land cover resulted in the following impacts: decreasing biodiversity, increasing the risk of floods, increasing damage to mangroves, and decreasing rice production. The prevention of land-use change to maintain environmental sustainability is a shared responsibility of all stakeholders.

Recovery of Carbon and Vegetation Diversity 23 Years after Fire in a Tropical Dryland Forest of Indonesia

Understanding the recovery rate of forest carbon stocks and biodiversity after disturbance, including fire, is vital for developing effective climate-change-mitigation policies and actions. In this study, live and dead carbon stocks aboveground, belowground, and in the soil to a 30 cm depth, as well as tree and shrub species diversity, were measured in a tropical lowland dry forest, 23 years after a fire in 1998, for comparison with adjacent unburned reference forests. The results showed that 23 years since the fire was insufficient, in this case, to recover live forest carbon and plant species diversity, to the level of the reference forests. The total carbon stock, in the recovering 23-year-old forest, was 199 Mg C ha−1 or about 90% of the unburned forest (220 Mg C ha−1), mainly due to the contribution of coarse woody debris and an increase in the 5–10 cm soil horizon’s organic carbon, in the burned forest. The carbon held in the live biomass of the recovering forest (79 Mg C ha−1) was just over half the 146 Mg C ha−1 of the reference forest. Based on a biomass mean annual increment of 6.24 ± 1.59 Mg ha−1 yr−1, about 46 ± 17 years would be required for the aboveground live biomass to recover to equivalence with the reference forest. In total, 176 plant species were recorded in the 23-year post-fire forest, compared with 216 in the unburned reference forest. The pioneer species Macaranga gigantea dominated in the 23-year post-fire forest, which was yet to regain the similar stand structural and compositional elements as those found in the adjacent unburned reference forest.

ANALISIS INDEKS BAHAYA EROSI DAN ARAHAN PENGGUNAAN LAHAN PADA DAS MAREK DS BAGIAN HULU KABUPATEN BONE

This study aims to analyze the amount of erosion that occurs and the erosion that can be tolerated in the upstream Marek DS watershed, analyze the erosion hazard index in the upstream Marek DS watershed, and analyze land use in accordance with conservation patterns that can be applied to land due to erosion. This research was conducted using the Universal Soil Loss Equation (USLE) method to determine the level of erosion (A) that occurred at the research site. Make changes to the C and P values to find the right direction for land use. The results show that the average erosion rate that occurs in the upstream Marek DS watershed is the largest on open land, which is 1107,965 tons/ha/year, and the tolerable erosion is 17,832 tons/ha/year on dry land mixed with shrubs. It amounted to 652.297 tons/ha/year and the tolerable erosion was 20,592 tons/ha/year. The erosion in shrubs was 613.999 tons/ha/year and the tolerable erosion was 17.456 tons/ha/year. The tolerable erosion rate in secondary dryland forest was 11,372 tons/ha/year and the rate of erosion was 17,103 tons/ha/year. The smallest erosion on rice fields was 0.125 tons/ha/year and the tolerable erosion was 29,275 tons/ha/year. The average erosion hazard index in the upstream Marek DS watershed has a low value of 0.280% or 10,822 ha, namely in paddy fields; a moderate value of 5.671% or 219.079 ha, namely in secondary dryland forest, and a very high value, respectively, on dry land. Dry land agriculture mixed with shrubs accounts for 48.102% (or 1858.305 ha), open land accounts for 0.779% (or 30.083 ha), and dry land agriculture mixed with bushes accounts for 45.168% (or 1744.942 ha).Recommendations for land use directions in the upstream Marek DS watershed in the form of natural forest with lots of litter in secondary dryland forest and shrubs, then recommendations for medium density mixed gardens and making bench terraces on open land, and finally recommendations for high-density mixed gardens and making bench terraces for agriculture. If natural forest is mixed with shrubs and shrubs, then the recommendation for natural forest is less litter on open land.

Recruitment credit cannot compensate for extinction debt in a degraded dry Afromontane forest

AbstractQuestionAnthropogenic disturbances severely affect dryland forests worldwide, but their effects on woody species population structure and long‐term persistence remain poorly understood.LocationThe research was conducted in Desa'a, a dry Afromontane forest in northern Ethiopia, Tigray region.AimsWoody species diversity, extinction debt, recruitment credit and colonisation credit were quantified and mapped based on an inventory of mature and regenerating individuals in 303 systematically sampled plots.MethodsTo assess tree species population dynamics at the neighbourhood scale, each plot was pooled with 16 neighbouring plots, in which species composition in the mature and regeneration layers was compared to determine the number of regenerating species, extinction debt, recruitment credit and colonisation credit. At the regional scale (150,000 ha), all plots were pooled to obtain the number of regenerating species, extinction debt and recruitment credit.ResultsThe average density of the mature layer was 1,482 individuals per ha, representing 84 species and 44 families, with Juniperus procera and Olea europaea dominating. The regeneration layer had an average density of 14,909 individuals per hectare, with Dodonaea angustifolia and Cadia purpurea dominating. At the neighbourhood scale, the average number of regenerating species, extinction debt, recruitment credit and colonisation credit amounted to 12, 13, 5 and 68 species. Regionally, there were 58 regenerating species, an extinction debt of 26 species, and a recruitment credit of 12 species. Extinction debt was more than twice as high as recruitment credit at both the neighbourhood and regional scale.ConclusionAlthough regeneration density seemed sufficient to maintain forest density, it consisted of only a few species and is inadequate to maintain species diversity. It is urgent that forest managers recognise this and step‐up conservation and restoration efforts in this important forest relic. Assisted restoration is needed for those species potentially at risk of extinction.

KLASIFIKASI TUTUPAN LAHAN PADA HUTAN LINDUNG GUNUNG SIRIMAU KOTA AMBON

Protected forest is a forest area that has the main function of protecting life support systems, to arrange water management, preventing flooding, erosion and sea water intrusion. The information of land cover is very important to determine the distribution of spatial use patterns on environmental conditions and regional spatial planning. This research aims to know the classification of land cover in Gunung Sirimau Protected Forest area in 2000, 2009 and 2019, and to identify the level of accuracy of the classification. This research used remote sensing and GIS methods to identify land cover classes using land cover maps released by the Ministry of Environment and Forestry in 2000, 2009 and 2019. The results of this research are classification of land cover in 2000 consist of primary dryland forest, secondary dryland forest, shrubs, and mixed dryland farming. Land cover in 2009 has an additional classification that is residential land, and in 2019 also has an additional classification that is open land. Overall accuracy value with ground checking obtained accuracy level 86,67% from 15 sample points.

Genetic variation in wood properties of mid-rotation age Eucalyptus globoidea

Background: Eucalyptus globoidea Blakely produces ground-durable (Class 2) and stiff wood and has the potential to be grown in New Zealand to supply high-value environmentally-friendly timber for use as posts in the agricultural sector and stiff veneers for the LVL industry. The New Zealand Dryland Forests Initiative (NZDFI) has established a breeding programme for this species. The objective of this study was to identify trees with superior wood properties for commercial propagation enabling the establishment of a domestic plantation resource of ground-durable timber. Methods: The genetic variation in wood properties at mid-rotation age (8-year-old) of 141 E. globoidea families was assessed for the following traits: heartwood diameter, diameter under bark at ~0.5 m height, combined sapwood diameter, heartwood collapse, sapwood collapse, standing tree acoustic velocity and extractive content in the heartwood. Families were ranked and genotypes with large heartwood diameter, high extractive content and stiffness as well as low collapse were identified. Results: Heartwood diameter (h2 = 0.51) and extractive content (h2 = 1.16) showed good heritability, which in combination with high variation are promising traits for a breeding programme. The high heritability for extractive content indicated a closer relatedness within the population than the assumption of unrelated families of half-siblings. The unfavourable correlation between the heartwood diameter and extractive content (genetic correlation (rg) = −0.45) indicated that a compromise is required for simultaneous improvement of both traits. Heritability estimates for heartwood collapse (h2 = 0.30) and acoustic velocity (h2 = 0.36) were moderate. Conclusions: Genetic selection for wood quality traits of E. globoidea is practically feasible. Superior individuals with above average performance for multiple traits were present in the breeding populations, however, this was dependent on the intended end use of the timber.

Spatial distribution of tree species composition and carbon stock in Tozi tropical dry forest, Sinnar State, Sudan

Abstract. Yasin EHE, Mulyana B. 2022. Spatial distribution of tree species composition and carbon stock in Tozi tropical dry forest, Sinnar State, Sudan. Biodiversitas 23: 2359-2368. Dryland forest ecosystem in Sudan plays an important role, either ecologically or economically, for the community around the forest areas. However, land-use change, illegal logging and grazing have caused dryland forests in the country to degrade. The research aimed to investigate the species composition and carbon stock in a Tozi tropical dry forest (TTDF), a typical dryland forest ecosystem in Sinnar state, Sudan. A total of 306 circular sample plots (1000 m2 for each) were established using a systematic sampling grid method. The distance between plots was 400 m and between survey lines 500 m. In each plot, all living trees were identified and counted, and their diameter at the breast height (DBH) was recorded. Research findings showed that there were 2,339 individual trees representing four species (Acacia seyal, Balanites aegyptiaca, Acacia senegal and Acacia mellifera) that belong to two families. The B. aegyptiaca and A. seyal were the dominant species widely distributed in the TTDF. The average tree density was 175 trees/ha and the Shannon-Weiner index for trees diversity was 0.264. For the seedlings stage, A. mellifera showed a high value of frequency and density, followed by B. aegyptiaca and A. seyal. The structure of seedlings, saplings, and adults trees formed a reverse J-shape in which the density of seedlings was the highest and followed by saplings and adult trees. Carbon stock of A. seyal, B. aegyptiaca, A. senegal, and A. mellifera were 990.95, 2602.78, 1085.82, and 249.20 kg C/ha, respectively. Spatial analysis showed that sites composed of three species resulted in the highest above ground carbon stock compared to single species, two species, and four species compositions.

Identifikasi Potensi Longsor Berbasis Sistem Informasi Geografis di Kecamatan Sembalun Kabupaten Lombok Timur

This study aims to assess and map the spatial potential of landslides based on a geographic information system in Sembalun District. Field surveys were carried out from May to July 2020 on a land area of ​​18,318.45 Ha. Field observations include land characteristics, climatic characteristics (rainfall), soil properties in various types of land use. (shrubs, plantations, open land, dry land agriculture, residential and industrial areas, primary and secondary dryland forest. Soil sampling at a depth of 0-15 cm is carried out in a composite manner at 16 sampling points to determine soil properties, namely permeability, texture, structure and status of soil organic matter Data processing (slope, rainfall, geology, land use and erodibility) for the mapping process in the form ofshapefileand generate landslide prone maps from the overlay process. Landslide potential estimation using the method specified by Directorate of Volcanology and Geological Disaster Mitigation/DVMBG (2004). Score = (30% x rainfall class factor) + (20% x geology) + (20% x Erodibility class factor) + (15% x land use) + (15% x slope class factor). The results showed that around 32% (5,901.53 Ha) of the area of ​​Sembalun Subdistrict were in a high vulnerability status to landslide potential, 49% (8,911.39 Ha) were at moderate vulnerability status and 19% (3,505.71 Ha) had low vulnerability. The variables of erodibility and slope are the variables that show the most significant contribution to the potential for landslides in the area.

Differences in the short-term responses of soil nitrogen and microbial dynamics to soil moisture variation in two adjacent dryland forests

Periodic droughts and extreme rainfall are predicted to become more common in the future; therefore, it is important to understand how soil N transformation processes driven by soil microbes respond to rainfall events. Differences in forest type, including those in the predominant mycorrhizal type, can have varying effects on soil N transformation. Therefore, we hypothesised that the response of the N transformation processes to rainfall events would differ between forest types, even those that are adjacently located. In this study, we generated a soil moisture gradient in adjacent dryland black locust (Robinia pseudoacacia, non-ectomycorrhizal [ECM]-type) and oak (Quercus liaotungensis, ECM-type) forests and measured the abundance and community composition of fungi and prokaryotes (including ammonia-oxidisers), extractable N content, and net N transformation rates in the soil. Increasing moisture was found to increase nitrate N content in the black locust forest but not in the oak forest. In the oak forest, the abundance of ECM fungi increased with increasing moisture, subsequently enhancing ECM fungal ammonium N uptake and limiting the N availability for ammonia oxidisers, which may reduce the nitrate N production by ammonia-oxidisers. Increased nitrate N uptake by ECM fungi may also result in low soil nitrate N content. The findings of this study indicate that the responses of the nitrate N dynamics to rainfall events can differ between adjacent forests and that this difference may be attributable to the presence of ECM fungi. Therefore, considering the forest mycorrhizal type is vital for predicating the response of forest N cycling under climate change.

New paleoenvironmental and palynostratigraphic data from Solimões Formation (Solimões Basin, Amazonas, Brazil)

The Western Amazon was affected by tectonic events of great impacts, such as the uplift of the Andes during the Neogene. Such events promoted significant changes in the fluvial drainage system, in the climate, as well as in the ecosystems, triggering great irradiation of the Amazonian biota. Marine evidence recorded in the region also influenced the radiation of the biota. Despite advances in the paleoenvironmental and age models proposed for the Western Amazon deposits, we still observe conflicting results and interpretations on these aspects. Thus, here were analyzed the palynological content of three cores aimed to contribute with new paleoenvironmental and biostratigraphic data of the Solimões Formation. We presented new paleobotanical data from the 1AS-5-AM, 1AS-7D-AM, and 1AS-8-AM cores and correlated the biostratigraphic data already published with the data obtained here; were recognized five palynozones (Verrutricolporites, Psiladiporites, Crassoretitriletes, Grimsdalea, and Asteraceae), reaching a range from the early to the late Miocene. The vegetation throughout the sequences studied includes elements of dryland forest next to zones of wetlands vegetation, including flooded forests and swamps; the floristic composition changed over time, predominating flooding vegetation during the early and part of the middle Miocene.

Analysis of land cover changes due to forest fires in Gunung Leuser National Park, North Sumatra Province, Indonesia

Abstract. Thoha AS, Saraswita N, Sulistiyono N, Wiranata D, Sirait SM, Inaldi R. 2022. Analysis of land cover changes due to forest fires in Gunung Leuser National Park, North Sumatra Province, Indonesia. Biodiversitas 23: 1420-1426. Forest and land fires occur almost every year with significant impacts and losses on the environment and various sectors including conservation areas. Gunung Leuser National Park (GLNP) is a conservation area in danger of losing its forest cover due to slash-and-burn land clearing. This study aimed to analyze land cover changes due to forest and land fires in GLNP of North Sumatera Province. Data of hotspots, satellite images, land cover maps, and field verification were used to see the transition of land cover changes before and after forest and land fires. Temporal and spatial analyses were carried out to see the trend of these changes. Field surveys were also conducted to verify hotspots as locations for forest fires, burned land, and human activities causing the fires. This study found that 2010 had the highest hotspots reported from 2001 to 2019. There were indications of a fairly massive forest fire in 2010, as evidenced by the identification of burned land on satellite images. The burned land was near the outer boundary of the GLNP area and expanded into the area in the following period. Before 2010, the area of the non-forest cover was not too large. After 2010, there was an increase in non-forest land cover, presumably due to increased access to enter the area after the forest was cleared after the fire. During almost 20 years, the primary dryland forest in the study area remained only 6% of the initial area. At least more than 200 ha of forest area is reduced in the study area every year. The burned lands in the following years tended to become plantation land. Plantation land cover increased by around 90% during 2000-2019 in the research sites. This study expects that GLNP management and various parties need to prevent the expansion of forest clearing because the strategic role of GLNP as a world heritage is currently in danger.

Identification of Land Cover Types and Their Changes in Kutalimbaru Sub-district, Deli Serdang District, North Sumatra, Indonesia

In recent years, land cover changes in Deli Serdang District, North Sumatra Province, have become a problem that needs to be addressed immediately. This study aims to determine the type of land cover that has changed over a ten-year period that occurred in the Kutalimbaru Sub-district. Kutalimbaru Sub-district is upstream of the Belawan Watershed. The method used in this study is a change detection method using a geographic information system (GIS). The results showed ten types of land cover in the Kutalimbaru District: dryland forest, paddy field, mixed garden, open land, oil palm plantation, rubber plantation, settlement, shrubs, water body, and industry. Land cover in Kutalimbaru Sub-district in 2019 was dominated by mixed gardens (39.51), followed by oil palm plantations 23.13% and dryland forests 12.58%. Over ten years, there was a change in land cover from dry land forest to the mixed garden (14.42 ha) and open land (9.22 ha). A significant change occurred in land cover from mixed garden to oil palm plantation (1,783.41%) and to open land (1,178.37 ha). In addition, a change in land cover from mixed garden to settlement (154.99 ha) also occurred in this area.

The habitat suitability of Timor friarbird (Philemon inornatus) in Western Timor Island, Indonesia

Abstract. Paga B, Pudyatmoko S, Wijayanti LR, Yuda P, Sulaksono N. 2021. The habitat suitability of Timor friarbird (Philemon inornatus) in Western Timor Island, Indonesia. Biodiversitas 23: 703-713. Timor friarbird is an endemic bird to Timor Island. The population of this bird has been declining due to land cover changes as a result of massive anthropogenic pressures. This study aimed to assess the suitability of Timor friarbird's habitat by using 12 ecogeographical variables. The sources of data included Sentinel 2A satellite imagery and remote sensing-based algorithms. The bird's presence was analyzed by using a combination of line transect with point count methods. Ecological Niche Factor Analysis (ENFA) model was applied to obtain habitat suitability value as well as coefficient of marginality (M) and specialization (S). These results showed that the Timor friarbird needs a habitat with a different value from the average of the entire habitat. High specialization value indicated that the species has a narrow ecological niche. Factors influencing habitat suitability included the distance from roads, the presence of mangroves, primary and secondary dryland forests, rivers, and low-density settlements. About 75% of the study area is classified as unsuitable habitat, and only 22% is suitable with range classes of suitability from marginal to optimal habitat. Areas with less anthropogenic pressure on the land cover will be preferred more by the bird. Improvement of unsuitable habitat and protection of suitable habitat, therefore, will be the most important strategy for Timor friarbird conservation.

A Hawaiian Tropical Dry Forest Regenerates: Natural Regeneration of Endangered Species under Biocultural Restoration

Tropical dry forests (TDFs) are among the most at-risk ecosystems globally. In Hawai‘i, more than 45% of TDF species are threatened or endangered. Despite decades of active TDF restoration, there remains limited information on the potential for long-term success, since there are few studies of natural regeneration. We assess natural regeneration of endangered plants at Ka‘ūpūlehu dryland forest, a Hawaiian biocultural restoration initiative. Drawing on 6 annual censuses we (1) assess rates and patterns of natural regeneration across species and as a function of rainfall and (2) identify bottlenecks. Our surveys document natural recruits of 11 of the 12 endangered species first outplanted 15–20 years ago. Higher annual rainfall increased the number of new recruits per year and growth, but decreased survival of larger recruits. The total number of natural recruits increased three-fold over the study period and varied across species. For nearly half of the species, we documented a second generation of recruits. Successes appear to be a function of time, including a changing microclimate and adaptive management practices. Remaining bottlenecks include lack of seed dispersal, and seed predation and herbivory by introduced species. The success at Ka‘ūpūlehu highlights the potential for TDF restoration and the value of a biocultural approach.

Nature-based framework for sustainable afforestation in global drylands under changing climate.

Drylands cover more than 40% of Earth's land surface and occur at the margin of forest distributions due to the limited availability of water for tree growth. Recent elevated temperature and low precipitation have driven greater forest declines and pulses of tree mortality on dryland sites compared to humid sites, particularly in temperate Eurasia and North America. Afforestation of dryland areas has been widely implemented and is expected to increase in many drylands globally to enhance carbon sequestration and benefits to the human environment, but the interplay of sometimes conflicting afforestation outcomes has not been formally evaluated yet. Most previous studies point to conflicts between additional forest area and water consumption, in particular water yield and soil conservation/desalinization in drylands, but were generally confined to local and regional scales. Our global synthesis demonstrates that additional tree cover can amplify water consumption through a nonlinear increase in evapotranspiration-depending on tree species, age, and structure-which will be further intensified by future climate change. In this review we identify substantial knowledge gaps in addressing the dryland afforestation dilemma, where there are trade-offs with planted forests between increased availability of some resources and benefits to human habitats versus the depletion of other resources that are required for sustainable development of drylands. Here we propose a method of addressing comprehensive vegetation carrying capacity, based on regulating the distribution and structure of forest plantations to better deal with these trade-offs in forest multifunctionality. We also recommend new priority research topics for dryland afforestation, including: responses and feedbacks of dryland forests to climate change; shifts in the ratio of ecosystem ET to tree cover; assessing the role of scale of afforestation in influencing the trade-offs of dryland afforestation; and comprehensive modeling of the multifunctionality of dryland forests, including both ecophysiological and socioeconomic aspects, under a changing climate.

Linking between Water Use Efficiency and Leaf Area Index Along an Aridity Gradient in Dryland Forests

Linking between Water Use Efficiency and Leaf Area Index Along an Aridity Gradient in Dryland Forests

SUSTAINABLE APPROACHES FOR COMMUNITY INVOLVEMENT IN THE CONSERVATION AND MANAGEMENT OF DRYLAND FOREST AND THEIR BIODIVERSITY, A CASE OF KIJEGE FOREST, THARAKA NITHI COUNTY, KENYA

Community involvement is central in management and conservation of forests. Adjacent communities depend on these forests for livelihood and cultural values. Dryland forests are among the vital ecosystems in the environment and they face degradation due to undervaluation by surrounding communities even though they supply a range of important resources. This study aimed at determining sustainable approaches for community involvement in management and conservation of Kijege forest and its biodiversity. Specifically, the study determined the importance and values of Kijege forest to community, the role of community involvement in management, and sustainable approaches for community involvement in conservation and management of Kijege forests and its biodiversity. Interviews were conducted with the KFS officials, village elders, local community and other relevant leaders. The results revealed that, although 90% of the respondents depended on the forest for their livelihoods, especially for supply of wood fuel, and pasture during dry seasons, only 6.7% have ever, or are being involved in management of the forest. From the findings, it is clear that the level of involvement of community members is very low, hence the study outlines three key recommendations to improve community involvement including: formation of Community Forest Association, capacity building of the community members, and formulation of a Forest management plan to foresee the sustainable involvement of the formed CFAs for better conservation and management of Kijege Forest and its biodiversity.

The Floodplain Forests of the Mamberamo Basin, Papua, Indonesia (Western New Guinea): Vegetation, Soils, and Local Use

New Guinea is the world’s largest, most speciose, and most culturally rich tropical island, and the little-studied Mamberamo Basin of Papua (Indonesian New Guinea) is recognised among the region’s most-important areas for biological diversity. Here, we examined the floodplain forests in the indigenous territory of Papasena, within the Mamberamo-Foja Wildlife Reserve in the Mamberamo Basin. As part of a training activity with local researchers, students, and civil servants, and with the permission and assistance of the local people, we employed various methods including the field surveys detailed here. We used variable-area tree plots, transects for non-trees and soil sampling, and local informants to document 17 plots: four in old-growth dryland forest, five in old-growth swamp forests (two seasonally flooded and three permanently wet including one dominated by sago, Metroxylon sagu Rottb.), five in secondary forest (fallows), and three in gardens (two in swamps and one on dryland). In total, we measured 475 trees over 10 cm in diameter at 1.3 m (dbh). The swamp forests had high local basal areas (highest value 45.1 m2 ha−1) but relatively low statures (20 m but with emergent trees over 40 m). In total, 422 morphospecies from 247 genera and 89 different families were distinguished. These included 138 tree species and 284 non-tree plant species. A quarter (105) of the morphospecies lacked species-level identifications. The woody families Rubiaceae, Araceae, Moraceae, and Euphorbiaceae were especially diverse, with 20 or more morphospecies each. Tree richness was highest in dryland forest (plot 7 having 28 species in 40 stems over 10 cm dbh) with more variation in the flooded forests. Non-tree vegetation showed similar patterns ranging from 65 species in one 40-by-5 m primary forest plot to just 5 in one seasonally flooded forest plot. The local people identified many plants as useful. Among trees, at least 59 species were useful for construction (the most common use), while, for non-trees, medicinal uses were most frequent. Inceptisols dominated (12 plots), followed by Ultisols and Entisols (3 and 2 plots, respectively). Drainage appeared poor and nutrient availability low, while land-suitability criteria implied little potential for crops aside from sago. We discuss the implication of local practises and more recent developments that may threaten the conservation of these floodplain systems. We underline the key role of local people in the oversight and protection of these ecosystems.

Application of Geographic Information Systems and Sediment Routing Methods in Sediment Mapping in Krueng Jreu Sub-Watershed, Aceh Province, Indonesia

Land management in the Krueng Jreu sub-watershed (Aceh Province, Indonesia) that did not follow soil and water conservation methods encouraged erosion. This can lead to silting of rivers or irrigation canals due to sediment deposition. Limited tools were the main reason for the infrequent measurement and mapping of these sediments in watersheds. Therefore, this study aims to conduct sedimentary mapping using GIS techniques combined with the sediment routing method to successfully produce a map of sediment assessment criteria for the Krueng Jreu sub-watershed area from 2010 to 2019. Rainfall and spatial data from the Krueng Jreu sub-watershed were analyzed to obtain several parameters of surface runoff, peak discharge, erodibility, slope, the value of ground cover, and land management. The results show that the Krueng Jreu sub-watershed was included in the wet climate type. The type of land use classification of savanna accounted for the most significant runoff, and land use type of open soil gave the smallest runoff. The maximum erosion found in the secondary dryland forest type land classification. It was known that the type of secondary dryland forest land use was the most significant contributor to sediment occurrence in the Krueng Jreu sub-watershed area.