scholarly journals Spatial Variation of Surface Soil Available Phosphorous and Its Relation with Environmental Factors in the Chaohu Lake Watershed

2011 ◽  
Vol 8 (8) ◽  
pp. 3299-3317 ◽  
Author(s):  
Yongnian Gao ◽  
Junfeng Gao ◽  
Jiongfeng Chen
Keyword(s):  
Environmental Factors ◽  
Spatial Variation ◽  
Surface Soil ◽  
Chaohu Lake

Bioeroding sponge assemblages: the importance of substrate availability and sediment

2018 ◽  
Vol 99 (2) ◽  
pp. 343-358 ◽  
Author(s):  
Joseph Marlow ◽  
Christine H.L. Schönberg ◽  
Simon K. Davy ◽  
Abdul Haris ◽  
Jamaluddin Jompa ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Sponge Species ◽  
Coral Mortality ◽  
Substrate Availability ◽  
Abiotic Conditions ◽  
Assemblage Composition ◽  
Reef Health

Despite global deterioration of coral reef health, not all reef-associated organisms are in decline. Bioeroding sponges are thought to be largely resistant to the factors that stress and kill corals, and are increasing in abundance on many reefs. However, there is a paucity of information on how environmental factors influence spatial variation in the distribution of these sponges, and how they might be affected by different stressors. We aimed to identify the factors that explained differences in bioeroding sponge abundance and assemblage composition, and to determine whether bioeroding sponges benefit from the same environmental conditions that can contribute towards coral mortality. Abundance surveys were conducted in the Wakatobi region of Indonesia on reefs characterized by different biotic and abiotic conditions. Bioeroding sponges occupied an average of 8.9% of available dead substrate and variation in abundance and assemblage composition was primarily attributed to differences in the availability of dead substrate. Our results imply that if dead substrate availability increases as a consequence of coral mortality, bioeroding sponge abundance is also likely to increase. However, bioeroding sponge abundance was lowest on a sedimented reef, despite abundant dead substrate. This suggests that not all forms of coral mortality will benefit all bioeroding sponge species, and sediment-degraded reefs are likely to be dominated by a few resilient bioeroding sponge species. Overall, we demonstrate the importance of understanding the drivers of bioeroding sponge abundance and assemblage composition in order to predict possible impacts of different stressors on reefs communities.

Seasonal and spatial variation of nitrogen dynamics in the litter and surface soil layers on a tropical dry evergreen forest slope

2010 ◽  
Vol 259 (8) ◽  
pp. 1502-1512 ◽  
Author(s):  
Naoyuki Yamashita ◽  
Seiichi Ohta ◽  
Hiroyuki Sase ◽  
Jesada Luangjame ◽  
Thiti Visaratana ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Surface Soil ◽  
Nitrogen Dynamics ◽  
Evergreen Forest ◽  
Soil Layers ◽  
Dry Evergreen Forest ◽  
Tropical Dry Evergreen Forest

Temporal and spatial variation of surface soil water content on karst slopes in dry season

2015 ◽  
Vol 35 (19) ◽  
Author(s):  
张川 Zhang Chuan ◽  
张伟 Zhang Wei ◽  
陈洪松 Chen Hongsong ◽  
聂云鹏 Nie Yunpeng ◽  
叶莹莹 Ye yingying ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Surface Soil ◽  
Dry Season ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial

Spatial variation in soil physical properties and effects on soil NO3– production on forest hillslopes

2020 ◽  
Author(s):  
Tomoki Oda ◽  
Megumi Kuroiwa ◽  
Naoya Fujime ◽  
Kazuo Isobe ◽  
Naoya Masaoka ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Soil Moisture ◽  
Physical Properties ◽  
Spatial Variation ◽  
Volcanic Ash ◽  
Surface Soil ◽  
Soil Physical Properties ◽  
Slope Position ◽  
Surface Soil Moisture ◽  
Slope Bottom

<p>Ammonium (NH<sub>4</sub><sup>+</sup>) and nitrate (NO<sub>3</sub><sup>–</sup>) concentrations and production rates in forest soil vary by hillslope position due to variation in ammonia-oxidizing microorganism concentrations, soil chemistry, and surface soil moisture. These spatial distributions have a significant effect on nutrient cycles and streamwater chemistry. Soil moisture conditions significantly restrict microbial activity, influencing the spatial distribution of NO<sub>3</sub><sup>–</sup> concentrations on forest hillslopes. However, studies linking forest hydrological processes to nitrogen cycling are limited. Therefore, we investigated the determinants of spatial variation in soil moisture and evaluated the effects of soil moisture fluctuations on spatial variation in NO<sub>3</sub><sup>–</sup> concentration and production rate.</p><p>The study sites were the Fukuroyamasawa Experimental Watershed (FEW) and Oyasan Experimental Watershed (OEW) in Japan. The two have similar topographies, climates, and tree species. In each watershed, a 100 m transect was set up from the ridge to the base of the slope, and soil moisture sensors were installed at soil depths of 10 cm and 30 cm at both the top and bottom of the slope. We collected surface soil samples at a depth of 10 cm at the top, middle, and bottom of the slopes using 100 cm<sup>3</sup> cores, and measured soil physical properties, particle size distribution, volcanic ash content, chemical properties (pH, NO<sub>3</sub><sup>–</sup>, NH<sub>4</sub><sup>+</sup>, nitrification rate, and mineralization rate), and microbial content (archaeal content). Spatial and temporal changes in soil moisture on the hillslope were calculated using HYDRUS-2D to examine contributing factors of soil moisture.</p><p>At FEW, high NO<sub>3</sub><sup>–</sup> concentrations and nitrification rates were observed only at the slope bottom and middle, and no NO<sub>3</sub><sup>–</sup> concentrations were detected at up slope. By contrast, at OEW, high NO<sub>3</sub><sup>–</sup> concentrations and nitrification rates were observed at all points. NH<sub>4</sub><sup>+</sup> concentrations were similar at all points in both watersheds. At FEW, 10 cm surface soil moisture fluctuated within 25–40% at the slope top but was within 40–50% at the slope bottom. At OEW, surface soil moisture was 30–40% at both the slope top and bottom, with no significant differences according to slope position. It was confirmed that soil moisture was significantly involved in NO<sub>3</sub><sup>– </sup>concentration and nitrification rates. Model simulations showed that the difference in soil moisture fluctuations between FEW and OEW was mainly explained by the spatial variation in soil physical properties. In particular, volcanic ash influenced soil moisture along the entire slope at OEW, resulting in high water retention, but only influenced soil moisture at the slope bottom at FEW. These findings indicate that spatial variability in soil physical properties has a significant effect on soil moisture fluctuation and leads to a spatial distribution of NO<sub>3</sub><sup>–</sup> production.</p>

scholarly journals PENGGUNAAN SISTEM INFORMASI GEOGRAFIS (SIG) DALAM ANALISIS DAYA DUKUNG DAN DAYA TAMPUNG LINGKUNGAN HIDUP DI KABUPATEN TANAH LAUT

INFO-TEKNIK ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 105
Author(s):  
Muhammad Syahirul Alim
Keyword(s):  
Information System ◽  
Environmental Factors ◽  
Natural Resources ◽  
Spatial Variation ◽  
Geographical Information System ◽  
Carrying Capacity ◽  
Geographical Information ◽  
High Category ◽  
Environmental Carrying Capacity ◽  
Very High

The objective of the study was to provide an overview of the using of Analytical Geographical Information System (GIS) to determine Environmental Carrying Capacity and Capability in Tanah Laut Regency Province of South Kalimantan. The combination methode of Pairwise Comparation and The spatial capacity offered by GIS is directly applicable to understanding the spatial variation by environmental factors. The result of this study shows that carrying capacity and capability can reflect a potential and availability of natural resources in the area of Tanah Laut Regency so that it can be known in which areas have the greatest potential and availability of indicators where the percentage distribution of the extent of the environmental carrying capacity of each ecosistem service potential and the most dominant availability are in the District of Jorong, which is 60% for the High category including 6 Ecosistem Services and 40% for the very high category for 4 Ecosistem Services. 30% Kintap Subdistrict for very high category for 3 Ecosistem Services and 20% for High category includes 2 Ecosistem Services.

scholarly journals Multivariate Analysis of Soil Salinity in a Semi-Humid Irrigated District of China: Concern about a Recent Water Project

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2104
Author(s):  
Jing Zhang ◽  
Dong Du ◽  
Dongli Ji ◽  
Yaonan Bai ◽  
Wanjun Jiang
Keyword(s):  
Multivariate Analysis ◽  
Environmental Factors ◽  
Soil Salinity ◽  
Surface Soil ◽  
Groundwater Table ◽  
Groundwater Depth ◽  
Alkaline Media ◽  
Irrigation Canals ◽  
The Impact ◽  
Density Of Irrigation

The Chaobai River (CBR) basin in northern China is experiencing an unprecedented continuous inflow of external water via the South–North Water Diversion Project, which has channeled water from the southern part of the country to the north. Consequently, the steady rise of groundwater table in recent years is threatening soil salinity regulation. The purpose of this study was to describe the status of salinity of the surface soil in the CBR basin and to evaluate the impact of environmental factors including groundwater table on the spatial distribution of soil salinity using multivariate analysis (MVA) technique. In this study, 10 chemical variables of soil samples collected in 204 sites along CBR were analyzed, considering their interaction with three environmental factors: the density of irrigation canals, groundwater depth and topography. Statistical analysis mainly consisted of principal component analysis (PCA), redundancy analysis (RDA) and clustering analysis (CA). The results allow defining the surface soil in the CBR basin as a slightly saline and moderately alkaline media. The first two axes of multivariate model approximately explains 51% of the observed variability and allows distinguishing two main domains: the saline and the alkaline. The variability of the saline domain, defined by major cations and anions, is obviously controlled by macro environmental factors, of which the density of irrigation canals and groundwater depth contributes 71% and 28%, respectively, while that of the alkaline domain, related to pH and bicarbonate, mainly manifests as singular behaviors of soil groups like rice cultivation or sewage irrigation. The results suggests that more attention should be paid to the ongoing water table rise to help inform future land management decisions and to prevent a double threat of both groundwater and surface water on soil salinization. Meanwhile, this study shows the enormous potential of MVA technique, specifically the complementary duo of RDA and CA, for integrating both global and local information of soil salinity and environmental factors.

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