The Influence of Paddy Fields toward The Seasonal Herbaceous Wetland Ecosystem in Rawa Pening Lake

Most of the tidal land in the lakeside of Rawa Pening is currently used for rice farming activities. This activity is thought to have negative impacts on seasonal herbaceous wetland ecosystem in this region. The study aimed to analyze the influence paddy fields toward the seasonal herbaceous wetland ecosystems in Rawa Pening Lake through an vegetation composition and structure approach. This study is a quantitative descriptive research with field observation method. Data of vegetation was collected using line intercept transect technique in the area widely of 625 m2 for each affected and unaffected ecosystem sample. Data analysis was performed by calculating the Sorensen Similarity Index (IS), the Margalef Diversity Index (R), the Shanon-Wiener Diversity Index (H'), the Dominance Index (C), and the Evenness Index (E). The results showed that there were differences in the composition and structure of vegetation on the two ecosystem samples, seen from the value of similarity index (IS) between both of them that included in the low criteria (39.85%). The results also showed that the Shanon-Wiener Diversity Index (H') and the Margalef Diversity Index (R) on the affected ecosystem sampleà (H' = 1,9834; R = 1,825) are lower when compared to the unaffected ecosystem sample (H'= 2,1297; R = 2,112). So it can be concluded that the existence of paddy fields has changed the composition and structure of vegetation and reduced the diversity of vegetation in the affected ecosystem. Based on these conclusions, it is recommended to construct a sustainable management system of paddy fields on Rawa Pening Lake's tidal land as the effort for natural ecosystems maintenance in this region, especially in the biodiversity and ecological services preservation

Impact of groundwater depth and soil salinity on riparian plant diversity and distribution in an arid area of China

Riparian plant diversity in arid regions is sensitive to changes in groundwater. Although it is well known that groundwater has a significant influence on plant diversity, there have been few studies on how groundwater and soil salinity impact plant community in desert riparian ecosystems. Therefore, we surveyed 77 quadrats (100m x 100m) to examine the relationship between groundwater depth, groundwater salinity, soil salinity and plant community in the upper reaches of the Tarim River. Data were analyzed with two-way indicator species analysis (TWINSPAN), detrended canonical correspondence analysis (DCCA) and principal component analysis (PCA). The results indicated that Populus euphratica, Tamarix ramosissima, and Phragmites australis were the dominant plants among trees, shrubs and herbs, respectively. Five plant community types were classified. There were significant differences in species diversity, soil moisture, soil salinity, groundwater depth and groundwater salinity across the community types. The composition and distribution of plant community are significantly influenced by groundwater depth, groundwater salinity, soil moisture, distances from the river to the quadrats, soil pH, electrical conductivity, total salt, CO32-, Cl-, SO42-, Ca2+, Mg2+, Na+ and K+. Shallow groundwater depth, low groundwater salinity, and high soil moisture and soil salinity were associated with higher plant diversity

Assessment of Riparian Ecosystem Health in the Tamiang River, Aceh, Indonesia as Remains Habitat of Batagur borneoensis (Schlegel & Muller, 1844)

The riparian zone along the Tamiang River, Aceh Province, is an important habitat for the survival of the tuntong laut (Batagur borneoensis) which is already threatened with extinction. This study aims to evaluate the quality and role of the riparian zone as a habitat for B. borneoensis along the Tamiang River, which can then be used as a reference in conservation. Riparian habitat quality was assessed by calculating the Qualitat del Bosc de Ribera (QBR) index, which was determined based on the total riparian cover, cover structure, cover quality, and channel alteration. In addition, observations of water quality (salinity, turbidity, and dissolved oxygen (DO)) and the number of riparian vegetation species were also carried out. Monitoring was carried out at five stations: Iyu River, Kampung Baru, Batang Lawang, Pusong Kapal Dermaga, and Pusong Kapal. The results showed variations in water quality between locations with DO and turbidity levels exceeding the quality standards set by the government. The richness of the types of riparian vegetation found ranged from 0-8 species (seedlings), 2-7 species (saplings), and 1-4 species (poles). The quality of riparian habitats in all study locations experienced significant degradation, including the euhemerobic and polyhemerobic (Hemeroby) categories, Cultural assisted system and Semi-transformed system (Naturalness), and Extreme degradation to poor-fair quality (QBR). The presence of B. borneoensis in the research location can adapt to the poor quality of riparian habitat. However, the density decreases significantly at higher salinity

Dynamic Simulation of Vegetation Abundance in a Reservoir Riparian Zone using a Sub-Pixel Markov Model

Vegetation abundance is a significant indicator for measuring the coverage of plant community. It is also a fundamental data for the evaluation of a reservoir riparian zone eco-environment. In this study, a sub-pixel Markov model was introduced and applied to simulate dynamics of vegetation abundance in the Guanting Reservoir Riparian zone based on seven Landsat Thematic Mapper/Enhanced Thematic Mapper Plus/Operational Land Imager data acquired between 2001 and 2013. Our study extended Markov model\u27s application from a traditional regional scale to a sub-pixel scale. Firstly, Linear Spectral Mixture Analysis (LSMA) was used to obtain fractional images with a five-endmember model consisting of terrestrial plants, aquatic plants, high albedo, low albedo, and bare soil. Then, a sub-pixel transitive probability matrix was calculated. Based on the matrix, we simulated statuses of vegetation abundance in 2010 and 2013, which were compared with the results created by LSMA. Validations showed that there were only slight differences between the LSMA derived results and the simulated terrestrial plants fractional images for both 2010 and 2013, while obvious differences existed for aquatic plants fractional images, which might be attributed to a dramatically diversity of water level and water discharge between 2001 and 2013. Moreover, the sub-pixel Markov model could lead to an RMSE (Root Mean Square Error) of 0.105 and an R2 of 0.808 for terrestrial plants, and an RMSE of 0.044 and an R2 of 0.784 for aquatic plants in 2010. For the simulated results with the 2013 image, an RMSE of 0.126 and an R2 of 0.768 could be achieved for terrestrial plants, and an RMSE of 0.086 and an R2 of 0.779 could be yielded for aquatic plants. These results suggested that the sub-pixel Markov model could yield a reasonable result in a short period. Additionally, an analysis of dynamics of vegetation abundance from 2001 to 2020 indicated that there existed an increasing trend for the average fractional value of terrestrial plants and a decreasing trend for aquatic plants