There have been many studies on rainfall erosivity and erosivity density (ED). However, it was not widely developed in Indonesia as a tropical country and has unique precipitation patterns. They are indicators for assessing the potential risk of soil erosion. The Air Bengkulu Watershed is undergoing severe land degradation due to soil erosion. This study aimed to analyze spatial-temporal in rainfall erosivity and ED based on monthly rainfall data (mm). The data used consisted of 19 weather stations during the period 2006–2020 and which are sparsely distributed over the watershed. The analysis was done by using Arnold’s equation. Then, the trend was tested using parametric and non-parametric statistics, and analysed with linear regression equation, and Spearman’s Rho and Mann Kendall’s tests. The spatial distribution of both algorithms was analysed using the inverse distance weighted (IDW) method based on the geographic information system (GIS). Unlike previous research findings, The long-term average monthly rainfall erosivity and ED revealed a general increase and decreasing trend, whereas it was found to be non-signifi- cant when both indices were observed. However, these results indicate a range from 840.94 MJ · mm−1 · ha−1 · h−1 · a−1,552.42 MJ · mm−1 · ha−1 · h−1 · a−1 to 472.09 MJ · mm−1 · ha−1 · h−1 · a−1 in that November month followed by December and April are the most susceptible months for soil erosion. Therefore, The upstream area of the region shows that various anthropogenic activities must be managed properly by taking into account the rainfall erosivity on the environment and that more stringent measures should be followed in soil and water conservation activities.
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Unusual occurrence of planktonic diatom species, Chaetoceros bacteriastroides and Chaetoceros pseudosymmetricus, was noticed in three different marine ecosystems of Adriatic Sea: the Krka Estuary and Telaščica Bay in the Central Adriatic, and in southern Adriatic offshore. From 2010 to 2015, these two Chaetoceros species were recorded in heterogeneous environmental conditions and in a very low abundances. Both species are regarded as very rare in world oceans, and consequently knowledge of their distribution and ecology is rather poor. Primarily described from tropical waters and showing Indo-Pacific distribution, C. bacteriastroides and C. pseudosymmetricus findings in Adriatic represent the northernmost records in world's oceans and seas. For C. pseudosymmetricus this is also the first occurrence in European seas. Areal expansion and introduction of new phytoplankton species in the Adriatic Sea might be related to different circulation regimes in the Ionian Sea and the concurrent rise in sea temperature in the Mediterranean in the last decade. Recent investigations have shown that entering currents, of either Atlantic/Western Mediterranean or Eastern Mediterranean origin, modify the composition of the plankton community in the Adriatic by bringing different newcomers.
Plastic debris has become a global problem due to its widespread distribution and accumulation in the marine environment. Indigenous bacteria in the marine environment are able to quickly contaminate plastic surface and assemble to form successional plastisphere-specific bacterial. The formation of microbial biofilms on the plastic surface can indirectly initiate the degradation of plastic polymers. The environmental conditions of the tropical region make the growth of microbial biofilms become faster. However, the study on the biodiversity of microorganisms in marine plastic debris is limited to the northern hemisphere, which includes subtropical and temperate regions. This review provides current studies of biodiversity and community structure of plastisphere in tropical environments, including bacteria and microalgae, and their potential to degrade the plastic polymer. A systematic literature search has been conducted using Scopus with different combinations of keywords. In addition, Google Scholar databases were also used to find more studies on some specific topics, including plastic degrading organisms. The climate-associated areas have been grouped according to the latitude of the study site into tropical, subtropical, and temperate latitudes. The microorganisms analyzed in this review are only bacteria, actinobacteria, and microalgae.
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