Shrub Areas Research Articles

Monitoring of Forest Land Cover Change in Binh Chau - Phuoc Buu Nature Reserve in Vietnam Using Remote Sensing Methods and GIS techniques

Binh Chau - Phuoc Buu Nature Reserve is located in the tropical rainforest zone of southeast Vietnam. For monitoring purposes of forest land cover change in Reserve satellite images (Landsat 5, Landsat 7 and Sentinel-2A) taken in 1988, 2003 and 2019 were used. NDVI was used for the estimation of vegetation quality. Forest land cover were classified by 5 categories using maximum likelihood classifier algorithm in ENVI 5.3. After classification, differentiation of forest land cover was analysed on every image. The results confirm that the area of meadows and shrubs increased from 16.3% in 1988 to 19.1% in 2019, and conversely, the area of broad-leaved forests decreased from 80.7% to 77.3%. Thus, there is a general degradation of forest vegetation.

Spatial heterogeneity in population change of the globally threatened European turtle dove in Spain: The role of environmental favourability and land use

AbstractAimTo describe the population trend for European turtle doves in Spain. To identify favourable and unfavourable areas for the species and to test whether favourability or land use explain spatial variation in abundance change.LocationMainland Spain.MethodsWe used generalized linear models with extensive abundance data to describe population change for the European turtle dove across Spain. We used breeding distribution (presence/absence) data at 100 km2 resolution to model environmental favourability in relation to topo‐climatic and land use variables. Finally, we tested whether land use and favourability explained spatial variation in abundance trends.ResultsThe large Spanish turtle dove population declined by 37% between 1996 and 2018. Favourability was highest in the south, east and north–west of Spain and lowest in the north and at higher altitudes. Abundance trends were more negative in areas of lower environmental favourability and in localities dominated by arboreal habitats such as forests, “dehesas” (open agro‐forestry landscapes with scattered Quercus trees), transitional woodland shrubs or sclerophyllous vegetation (a mixture of sclerophyllous shrubs with some scattered trees). Trends were more positive in localities dominated by complex cultivation (small parcels of mixed crop types, including woody permanent crops like olive, or almond trees or vineyards).Main conclusionsOur study highlights a substantial recent decline in the numerically important turtle dove breeding population in Spain. Declines in abundance were more strongly associated with arboreal (forest and shrub areas) rather than agricultural habitats, highlighting an urgent need for further research into the ecology of this important quarry species in arboreal breeding habitats in southern Europe.

Comparison of arthropod associates of French broom, Genista monspessulana (Linnaeus) (Fabaceae), and native shrubs on Mt. Tamalpais, Marin County, California, U.S.A.

The hypothesis that native plants have more arthropod associates than introduced plants was tested in chaparral and coastal scrub habitats which were being invaded by the exotic shrub Genista monspessulana (Linnaeus) (Fabaceae). Paired beat samples were taken from the shrubs. Data were analyzed by use of the Wilcoxon matched-pairs nonparametric method. Native shrubs had significantly more arthropod individuals and species associated with them than G. monspessulana. Most of the species collected on the exotic broom were native generalist herbivores, omnivores or predators, except for one native specialist herbivore and one exotic specialist herbivore that originated in the native range of G. monspessulana. The first was Uresiphita reversalis (Guenee, 1854) (Lepidoptera: Crambidae) and the second was Arytainilla spartiophila (Foerster, 1848) (Hemiptera: Psyllidae). These results suggest that efforts to control invasions of G. monspessulana into areas of native shrubs are warranted to conserve biological diversity.

Changes in land use and suitability of spatial planning on the paddy field in Gorontalo Regency

Agricultural land is the main and unique factor of agricultural production because it is difficult to replace in an agricultural business process. This research is intended to conduct a spatial study of changes in land use, especially paddy fields and the suitability of spatial use with the regional spatial plan (RTRW). In this study, an analysis of land-use change was carried out by comparing multitemporal land cover data (time series), and the suitability analysis of spatial use by comparing actual land cover data with the direction of spatial use specified in the RTRW document. Both of these analyses were carried out by overlaying maps using GIS (Geographic Information Systems) spatial data processing software. The results showed that within ten years (2007-2017), an increase in the total area occurred in the plantation (1.4%), built land (41.37%), dry land/fields (1.97%), and lake/body of water land-use class (11.14%). While the area of forest, paddy fields, and shrubs are reduced by 0.12%, 5.09%, and 6.68%, respectively. The results of overlaying actual land use maps with spatial pattern maps on Gorontalo Regency RTRW show that most (65.67%) land use in Gorontalo Regency is still following the direction of spatial use which has been specified in the RTRW. Whereas 34.13% of other land uses were identified as not yet suitable (30.57%) and not suitable (3.55%) with the RTRW. Land use that is not yet suitable is still possible to change to adjust the spatial Plan in the future. Regarding paddy fields, the land-use suitability matrix with the RTRW shows that 86.18% of the paddy fields in Gorontalo Regency are following the RTRW (located in the allotment of wetland agriculture areas), while the remaining 13.82% are not following the RTRW. There is also the potential for new paddy fields with a total area of 6,293 hectares.

Forest Vegetation Change and Its Impacts on Soil Water Following 47 Years of Managed Wildfire

Managed wildfire is an increasingly relevant management option to restore variability in vegetation structure within fire-suppressed montane forests in western North America. Managed wildfire often reduces tree cover and density, potentially leading to increases in soil moisture availability, water storage in soils and groundwater, and streamflow. However, the potential hydrologic impacts of managed wildfire in montane watersheds remain uncertain and are likely context dependent. Here, we characterize the response of vegetation and soil moisture to 47 years (1971–2018) of managed wildfire in Sugarloaf Creek Basin (SCB) in Sequoia-Kings Canyon National Park in the Sierra Nevada, California, USA, using repeat plot measurements, remote sensing of vegetation, and a combination of continuous in situ and episodic spatially distributed soil moisture measurements. We find that, by comparison to a nearby watershed with higher vegetation productivity and greater fire frequency, the managed wildfire regime at SCB caused relatively little change in dominant vegetation over the 47 year period and relatively little response of soil moisture. Fire occurrence was limited to drier mixed-conifer sites; fire-caused overstory tree mortality patches were generally less than 10 ha, and fires had little effect on removing mid- and lower strata trees. Few dense meadow areas were created by fire, with most forest conversion leading to sparse meadow and shrub areas, which had similar soil moisture profiles to nearby mixed-conifer vegetation. Future fires in SCB could be managed to encourage greater tree mortality adjacent to wetlands to increase soil moisture, although the potential hydrologic benefits of the program in drier basins such as this one may be limited.

ПРОГНОЗ СОСТОЯНИЯ РАСТИТЕЛЬНОГО ПОКРОВА ЛЕСНЫХ УГОДИЙ ЗАПОВЕДНИКА ДОНГ НАЙ ВЬЕТНАМА

The study was conducted in Dong Nai Reserve, specially protected natural area (SPNA), Vietnam. It aims to analyze and forecast forest land cover in the Reserve. For these purposes were studied satellite images (Landsat 5, Landsat 7 and Landsat 8) taken in 2003, 2011 and 2019. The Normalized Difference Vegetation Index (NDVI) was used to identify vegetation quality. Forest land cover was divided into 5 categories using maximum likelihood classifier algorithm. In order to detect and evaluate forest land cover changes, supervised classification and image differencing method are applied. Then, Cellular Automata and Markov Chain model was employed for making forecast of forest land cover in this area. The results of the study indicate that forest land cover change is being transformed in Dong Nai Reserve. According to our estimation, from 2003 to 2019, the area covered by woody vegetation increased by 7.0 %. By 2035, the area of broad-leaved forests will increase by 1.6 %, due to a decrease in areas of meadows and shrubs. The dynamics of increasing forest land is explained by the measures taken by the Vietnamese government to expand the area of forests in SPNA.

Influence of Land Use Land Cover Change on Groundwater Recharge in the Continental Terminal Area of Abidjan, Ivory Coast

The process by which rainfall reaches the aquifer in a sedimentary area is infiltration. This process could be affected quantitatively or qualitatively by the changes in the land use land cover (LULC) as a result of anthropogenic activities which could affect groundwater reserves. This study focuses on the influence of LULC change on groundwater recharge in the context of urbanization and population growth. Four weather stations data and satellite image data were used in order to evaluate water infiltration which is the amount of water that reaches the piezometric surface from 1990 to 2016. The spatial-temporal LULC change in relation to urbanization sprawl was assessed based on a series of Landsat images for 1990, 2000 and 2016. The maximum likelihood pixel-based on classification method was used to analyze the spatial-temporal LULC dynamics. The Thiessen polygon method was used for the mean area precipitation computation. The recharge was determined using water balance method after determining the runoff based on the Soil Conservation Service curve number method. The results show an increase in built-up and agricultural land, while the forest and shrub areas declined with water body remaining unchanged over the period 1990-2016. The decline in forest could be imputed to the demographic and socio-economic growth as expressed by the expansion of agriculture and urbanization. Groundwater recharge and runoff results are respectively 34%, 20% in 1999; 21%, 46% in 2000 and 26%, 14% in 2016 of rainfall and show their strong dependence on precipitation and LULC change.

Fire Frequency and Related Land-Use and Land-Cover Changes in Indonesia’s Peatlands

Indonesia’s converted peatland areas have a well-established fire problem, but limited studies have examined the frequency with which they are burning. Here, we quantify fire frequency in Indonesia’s two largest peatland regions, Sumatra and Kalimantan, during 2001–2018. We report, annual areas burned, total peatland area affected by fires, amount of recurrent burning and associations with land-use and land-cover (LULC) change. We based these analyses on Moderate Resolution Imaging Spectroradiometer (MODIS) Terra/Aqua combined burned area and three Landsat-derived LULC maps (1990, 2007, and 2015) and explored relationships between burning and land-cover types. Cumulative areas burned amounted nearly half of the surface areas of Sumatra and Kalimantan but were concentrated in only ~25% of the land areas. Although peatlands cover only 13% of Sumatra and Kalimantan, annual percentage of area burning in these areas was almost five times greater than in non-peatlands (2.8% vs. 0.6%) from 2001 to 2018. Recurrent burning was more prominent in Kalimantan than Sumatra. Average fire-return intervals (FRI) in peatlands of both regions were short, 28 and 45 years for Kalimantan and Sumatra, respectively. On average, forest FRI were less than 50 years. In non-forest areas, Kalimantan had shorter average FRI than Sumatra (13 years vs. 40 years), with ferns/low shrub areas burning most frequently. Our findings highlight the significant influence of LULC change in altering fire regimes. If prevalent rates of burning in Indonesia’s peatlands are not greatly reduced, peat swamp forest will disappear from Sumatra and Kalimantan in the coming decades.

Tundra shrub expansion may amplify permafrost thaw by advancing snowmelt timing

The overall spatial and temporal influence of shrub expansion on permafrost is largely unknown due to uncertainty in estimating the magnitude of many counteracting processes. For example, shrubs shade the ground during the snow-free season, which can reduce active layer thickness. At the same time, shrubs advance the timing of snowmelt when they protrude through the snow surface, thereby exposing the active layer to thawing earlier in spring. Here, we compare 3056 in situ frost table depth measurements split between mineral earth hummocks and organic inter-hummock zones across four dominant shrub–tundra vegetation types. Snow-free date, snow depth, hummock development, topography, and vegetation cover were compared to frost table depth measurements using a structural equation modeling approach that quantifies the direct and combined interacting influence of these variables. Areas of birch shrubs became snow free earlier regardless of snow depth or hillslope aspect because they protruded through the snow surface, leading to deeper hummock frost table depths. Projected increases in shrub height and extent combined with projected decreases in snowfall would lead to increased shrub protrusion across the Arctic, potentially deepening the active layer in areas where shrub protrusion advances the snow-free date.

Impact of oil palm plantation on the butterfly diversity: a Case study in KGP & CNG, Ketapang, West Kalimantan

Oil palm plantation in Indonesia is rapidly growing, encouraging the expansion of oil palm plantation area. The expansion estimated may decrease the biodiversity including the butterfly diversity. The research aimed to see the impact of oil palm plantation on the butterfly diversity that occurs in KGP and CNG oil palm plantation. The research was conducted in July 2018 by strip transect method. Impact of the establishment oil palm plantation on butterfly diversity was determined by comparing the current butterflies found on oil palm plantations area with the butterflies found on the baseline (shrub area). The result showed an increase in butterfly diversity and species richness index in KGP and CNG oil palm plantation. Total number of species and richness index in both oil palm plantations area were higher than the baseline area. The establishment of oil palm plantation in KGP oil palm plantation result gaining 22 species and losing 2 species, while in CNG oil palm plantation result is gaining 31 species and losing 5 species.

Allometric relationships for Quercus gambelii and Robinia neomexicana for biomass estimation following disturbance

AbstractIn the southwestern USA, increases in size, frequency, and severity of wildfire are driving the conversion of forests to shrub‐dominated ecosystems. Increases in drought extent and severity, coupled with the way that shrub‐dominated systems are perpetuated by high‐severity fire, predisposes these post‐disturbance landscapes to remain in a non‐forest condition. Consequently, understanding the distribution of aboveground biomass in post‐disturbance, shrub‐dominated ecosystems is central to constraining the uncertainty surrounding how these ecosystems interact with light and water to sequester carbon. Here we present allometric regressions for Quercus gambelii (Gambel oak) and Robinia neomexicana (New Mexico locust), two species that dominate post‐fire landscapes in the southwestern USA. Our allometric regressions are designed to be driven by either field plot or high‐resolution remote sensing data, using either shrub area or shrub volume to estimate biomass.

Leaf area index of Caatinga biome and its relationship with hydrological and spectral variables

Leaf area index (LAI) influences hydrological processes as both active and passive agents. In the Caatinga biome, little is known about LAI and its relationship with hydrological variables. Thus, the objective of this work was to measure LAI for a preserved arboreal-shrub vegetation and correlate it with hydrological variables (precipitation, evapotranspiration and soil moisture) and spectral (vegetation indices) in order to evaluate and to monitor their dynamics in time and space. The experiment was carried out in the Aiuaba Experimental Basin, considering three soil-vegetation associations and two periods (dry and rainy seasons) for three years (2014–2016). The results showed that LAI maximum is influenced by the type of soil-vegetation association and does not change over time. Among the hydrological variables, all had a significant correlation with LAI, but the best result was obtained using soil moisture. The best performance among the vegetation indexes for LAI estimation of the preserved Caatinga shrub-arboreal area was the Enhanced Vegetation Index (EVI), as shown by the analyses. The presence of clouds during the rainy season prevented a better evaluation of LAI with vegetation index. We concluded that the LAI of a preserved arboreal shrub area in Caatinga (3.5 ± 1.3 m2 m−2) can be monitored utilizing only precipitation, the precipitation-to-potential evapotranspiration ratio and soil moisture.

Effects of clear-cutting and wildfires on succession of ground beetle (Coleoptera: Carabidae) assemblages on the east slopes of the Rocky Mountains

We studied how carabid beetle assemblages in lodgepole pine stands have responded after clear-cut harvest and wildfires on an actively managed landscape ~20 km south of Hinton, Alberta, Canada. The work builds on and expands a previous study (Niemela et al. 1993) conducted 23-24 years earlier in many of the same stands sampled in the current study. Carabid species assemblages are compared along a chronosequence of stands ranging in age from 12 to 53 years after clear-cutting. Recovery of carabid assemblages toward pre-harvest structure in regenerating stands, as reflected in the 2013-14 data, appears to have progressed more rapidly than in equivalently aged stands from the earlier study. In addition, carabid species assemblages differed significantly between clear-cut and burned stands of comparable age in 2013-14, with assemblages of burned stands being more similar to the pre-harvest structure than in clear-cut stands. Ground vegetation, mineral soil cover and basal area of trees and shrubs were significantly correlated with structure of carabid species assemblages in young and old regenerating stands, suggesting that environmental and plant successional gradients drive patterns in carabid assemblages. However, assemblage differences between older burned and clear-cut stands indicate that the type of disturbance influences long-term carabid recovery. Relationships between these findings and issues related to conservation of biodiversity and climate change are discussed.

Relation between land cover and landslide susceptibility in Val d'Aran, Pyrenees (Spain): Historical aspects, present situation and forward prediction

The effects of land use and land cover (LULC) dynamics on landslide susceptibility are not fully understood. This study evaluates the influence of LULC on landslide susceptibility and assesses the historic and future LULC changes in a high mountain region.A detailed inventory map showing the distribution of landslides was prepared based on the 2013 episode in Val d'Aran, Pyrenees (Spain). This inventory showed that LULC clearly affected landslide susceptibility. Both the number of landslides and the landslide density triggered in grassland and meadow was highest (52% and 2.0 landslides/km2). In contrast, the landslide density in areas covered by forest and shrubs was much lower (15% and 0.4 landslides/km2, and 23% and 1.7 landslides/km2, respectively).Historical changes of LULC between 1946 and 2013 were determined by comparing aerial photographs. The results indicated that the forest and shrub areas increased by 68 and 65%, respectively; whereas grassland and scree areas decreased by 33 and 52%. Urban area also increased by 532%, especially between 1990 and 2001. Future LULC was predicted until 2097 using TerrSet software. The results showed that the forest area and urban area increased by 57 and 43%, severally; while shrubs, grassland and scree area decreased by 28, 46 and 78%, respectively.Heuristic and deterministic models were applied to create susceptibility maps, which classified the study area into four susceptibility degrees from very low to high. The maps were validated by the 2013 landslide dataset and showed satisfactory results using receiver operating characteristics curves and density graph method. Then, susceptibility maps until 2097 were calculated by the heuristic model and results revealed that landslide susceptibility will decrease by 48% for high-susceptible areas. In contrast, the areas of very-low susceptibility degree will increase 95%, while medium and low-susceptible areas will be more or less constant.This study only includes the effect of future LULC changes on the landslide susceptibility and does not analyze the future impacts of climate changes and the variation of rainfall conditions. Nevertheless, the results may be used as support for land management guidelines to reduce the risk of slope instabilities.

Assess the impact of land use changes on erosion and sedimentation in Dak Uy reservoir

Assess the impact of land use changes on erosion and sedimentation in Dak Uy reservoir

Do Red Foxes (Vulpes Vulpes) Increase the Detectability of Scent Marks by Selecting Highly Conspicuous Substrates

In mammals, especially those that are nocturnal or crepuscular, chemical marks usually play a significant role as environmental labels. Scent marks in mammals can have many functions, including territorial defense and communication signals in the mating season. Furthermore, animals can increase the detectability of marks by selecting highly conspicuous locations and substrates on which to mark, such as stones and sticks, on or around faeces, other animal carcasses, anthropogenic features, and plants. Human-carnivore interactions can result in a conflict where perceived damage to livelihoods occurs in socio-economically poor areas. In the Shigar Valley, Karakorum Range, Pakistan, subsistence mixed farming is the predominant land use and red foxes (Vulpes vulpes) are widely persecuted. Understanding the effects of human activity and habitat factors on fox behaviors in the region are lacking. We used line transect surveys aided by a domestic dog (Canis familiaris) to detect fox faeces locations and characterize fox den form 2015-16-17. We encountered 467 fox scats by dog assistance. We tested for associations between scent deposition, and environmental variables including vegetation and substrate type, distribution of livestock carcasses and dung, roads and agricultural land at micro-habitat. We found more fox scats on aromatic plants, shrubs, and on or near livestock feaces and carcasses. Fox scent marking site selection varied for forested and shrub areas relative to open grassland or barren ground and vegetation cover and tree density at the microhabitat scale. The findings suggest that foxes do not avoid human activity per se and anthropogenic benefits (road kill, livestock carrion, crop food sources) may outweigh the costs of persecution. Foxes may also provide ecosystem benefits via seed dispersal, carrion removal and regulation of prey populations.

Evaluation of ecosystem cultural services of urban protected areas based on public participation GIS (PPGIS): A case study of Gongqing Forest Park in Shanghai, China

Quantitative evaluation of ecosystem service value and its spatial mapping is an effective way to determine priority conservation areas of cultural ecosystem services (CES). We used a combination of questionnaires and structured interviews with public participatory GIS (PPGIS) in Gongqing Forest Park in Shanghai to connect non-monetary CES values with spatially explicit information. This method applied spatial indicators of abundance, diversity and rarity to quantitatively assess the value of CES and their spatial distribution, and identified priority CES areas. The results showed the value of CES varied among landscape types. Relatively open grassland, riverside, and shrub areas were associated with high aesthetic value. Riverside areas were associated with the CES category concerned with inspiration and supporting social relationships. High diversity values mainly distributed in riverside areas, while forest and grassland areas were associated with high rarity values. The areas with the highest values for the abundance, diversity, and rarity indices were overlaid with eight gradient thresholds, which indicated that defining the 25% of ecological areas with the highest overall rating as CES priority areas was an effective threshold for CES identification and management. The methodology in this study leveraged PPGIS to spatially refe-rence, quantify, and user perception to establish relationships between landscape attributes, space, and experience. These results could provide an important basis for identifying, planning for, and managing priority conservation areas in urban protected areas.

滇南喀斯特地区灌木群落和人工林土壤元素化学计量特征

PDF HTML阅读 XML下载 导出引用 引用提醒 滇南喀斯特地区灌木群落和人工林土壤元素化学计量特征 DOI: 10.5846/stxb201810072159 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划（2016YFC0502501） Characteristics of soil stoichiometry in native shrub and plantation communities in karst regions of Yunnan province Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在云南喀斯特地区，为提升退化灌木群落的生态系统服务功能，营造了不同树种的人工林分。这些人工林分如何影响土壤化学性质还未得到充分认识。以云南泸西县灌木群落及三种常见人工林（云南松（Pinus yunnanensis）、赤杨（Alnus japonica）和侧柏（Platycladus orientalis））土壤为研究对象探讨喀斯特地区在人工林建造后土壤的13种元素全量、可利用性含量和化学计量学特征变异格局，为喀斯特石漠化治理提供理论依据。结果表明，1）基于判别分析，四种群落土壤化学计量特征可以显著区分。土壤Fe、P、K、Mn全量及交换性Ca、交换性Mg和NH4+-N对区分四种群落土壤贡献最大。2）四种群落之间相比，侧柏林土壤C、N、S、Na全量和NO3--N含量均低于其他三种群落，土壤肥力较低；赤杨林铵态氮含量最高；云南松林有效Fe、有效Cu含量最高。而且，四个群落土壤全量C/N、C/K比值存在显著差异性。3）根据四种群落13种土壤元素和pH值相关性分析，35对元素具有显著相关性，占所有元素对数的38.5%，说明该地土壤元素积累的相互依赖性。与灌木群落相比，人工林土壤元素全量和可利用性含量相关性比例均更高。这些研究结果对今后基于适地适树人工林营造、生态系统服务功能提升和经营利用，均具有重要指导意义。 Abstract:The natural forest vegetation degraded to shrub-dominated plant communities in karst areas of Yunnan province, due to the geological conditions and long-term human disturbance. Plantation stands of different tree species have been established to raise ecosystem services across Yunnan province, such the karst shrub areas, during the last three decades. In this context, the elemental compositions of original soils could be influenced to a certain extent. In this study, we measured the total and available element concentrations of 13 elements (C, N, S, P, K, Ca, Mg, Na, Fe, Al, Cu, Zn, and Mn), and summarised the stoichiometric traits of soils in the shrub, Pinus yunnanensis, Alnus japonica, and Platycladus orientalis stands in Luxi county, Yunnan province. The results showed that firstly, soil stoichiometric traits of four communities were significantly distinguished based on canonical discriminant analysis. Furthermore, soil total Fe, P, K, Mn concentrations, and available Ca, Mg, and NH4+-N concentrations, contributed to the differences the most. Secondly, cypress stands showed lower total C, N, S, Na and NO3--N concentrations compared with the other three communities, suggesting that the soil fertility was reduced. The soil NH4+-N concentration was higher in alder stands compared with the other communities; the soil available Fe and Cu concentrations were highest in the Yunnan pine stand. Furthermore, there were also significant differences of C/N and C/K ratios among the four stands. Thirdly, based on a correlation analysis of the 13 elements and the pH value, 35 pair-elements showed a significant correlation, accounting for 38.5% of all elements, suggesting that there was strong inter-dependence accumulation of soil elements in these karst areas. Compared with the shrub community, the significant correlations between the total elements and available elements in plantation stands were higher. Our results have important implications for plantation establishment and management to increase ecosystem services in such karst areas. 参考文献 相似文献 引证文献

Threats of sedimentation to agricultural land due to land use and degradation of watershed physical environmental

<p class="abstract"><strong>Background:</strong> The Lake Lindu sub-watershed has experienced environmental damage, mainly as a result of various activities of the surrounding community who are less aware of the principles of environmental sustainability. This study aims to determine the effect of land use area and environmental physical conditions on sedimentation and water debit in the Lake Lindu sub-watershed.</p><p class="abstract"><strong>Methods:</strong> This research was carried out by implementing survey and non-experimental method at 3 rivers: Langko (P1), Wongkodono (P2), and Kati (P3). The dependent variable in this study is the area of land use (area of farm, shrub, paddy field, forest, and settlement) and the physical condition of the environment (the width of the catchment area and annual average rainfall). Then, the independent variables are sedimentation and water debit. Statistical analysis used is a multiple regression model. </p><p class="abstract"><strong>Results:</strong> The results of this study are that the wider shrub (X<sub>2</sub>) reduces the sedimentation (Y<sub>1</sub>) and increases the water debit (Y<sub>2</sub>). Each addition of one shrub unit will reduce the sediment by 0.208 mg/L and affect the water debit of 0.258 m<sup>3</sup>/ s-1. The regression equation is Y<sub>1</sub>=185.903 - 0.208X<sub>2</sub>-587.269X<sub>8</sub> and Y<sub>2</sub>=6.854+0.258 X<sub>2</sub> - 71.708 X<sub>8</sub>. As for the coefficient of the shape of the river (X<sub>8</sub>). The bigger the shape of the river, the smaller the average of the water debit. Thus, each reduction of one coefficient unit of the river shape will affect the water debit of 71,708 m<sup>3</sup> /s-1.</p><p class="abstract"><strong>Conclusions:</strong> The significant predictor factors for sedimentation and river water debit are the shrubs and the coefficient of the river shape.</p><p> </p>

The influence of vegetation types on the infiltration capacity of Ie Suum geothermal area in Mount Seulawah Agam

The availability of groundwater, largely influenced by the infiltration process and the vegetation cover types, is an important component for the sustainability of geothermal energy. The lack of reference in the relationship between infiltration and vegetation types in geothermal areas causes the lack of information to understand the overall availability of groundwater. Therefore, research on this subject is particularly significant. In this study, the focus was on the difference of the infiltration capacity among vegetation types in Ie Suum geothermal area of Mount Seulawah Agam in Aceh, Indonesia. The study employed the line transect method. The infiltration rate was measured by a double ring infiltrometer and was determined by Horton’s equation. Transect lines were determined according to the four directions of the winds (south, west, north and east) with the transect length at 500 m each. Then, in each transect line, three infiltration measurement points were set at 100 m, 300 m, and 500 m. The results showed that the infiltration capacity was extremely high in tree (9.08 cm/min) and shrub (5.12 cm/min and 3.41 cm/min) areas, but markedly low in herbaceous vegetation (0.57 cm/min). The differences in the infiltration rates for the tree, shrub, and herbaceous vegetation types indicated that the vegetation types affected the infiltration rates and also the groundwater availability in Ie Suum geothermal area.