Changes in soil pool capacity for lead in response to conversion of rainforest to rubber plantations in Hainan Island, China

2020 ◽  
Vol 31 (18) ◽  
pp. 3055-3070
Author(s):  
Yujie Zhou ◽  
Yong Qiu ◽  
Zhipeng Wu ◽  
Yujiao Xu ◽  
Jianhong Li ◽  
...  
Keyword(s):  
Hainan Island ◽  
Rubber Plantations ◽  
Soil Pool

scholarly journals Network complexity of rubber plantations is lower than tropical forests for soil bacteria but not fungi

2021 ◽  
Author(s):  
Guoyu Lan ◽  
Chuan Yang ◽  
Zhixiang Wu
Keyword(s):  
Network Structure ◽  
Tropical Rainforest ◽  
Soil Microbial Communities ◽  
Hainan Island ◽  
Past Research ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Microbial Composition ◽  
Rubber Plantations ◽  
Soil Microbial

Abstract. Soil microbial communities play a crucial role in ecosystem functioning. Past research has examined the effects of forest conversion on soil microbial composition and diversity, but it remains unknown how networks within these communities respond to forest conversion such as when tropical rainforest are replaced with rubber plantations. In this study, we used Illumina sequencing and metagenome shotgun sequencing to analyze bacterial and fungal community network structure in a large number of soil samples from tropical rainforest and rubber plantation sites in Hainan Island, China. Our results showed only a few shared network edges were observed in both bacterial and fungal communities, which indicates that forest conversion altered soil microbial network structure. We found a greater degree of network structure and a larger number of network edges among bacterial networks in samples from tropical rainforest compared to samples from rubber plantations. The difference was especially pronounced during the rainy season and indicates that rainforest bacterial networks were more complex than rubber plantation bacterial networks. However, rubber plantations soil fungal networks showed more higher links and higher network degree, suggesting that forest conversion does not reduce fungal network complexity. We found that some groups of Acidobacteria were keystone taxa in our tropical rainforest soils, while Actinobacteria were keystone taxa in rubber plantation soils. In addition, seasonal change had a strong effect on network degree, the complexity of soil bacterial and fungal network structure. In conclusion, forest conversion changed soil pH and other soil properties, such as available potassium (AK) and total nitrogen (TN), which resulted in changes in bacterial and fungal network composition and structure.

Decomposition and release of nutrients from leaf litter in rubber plantations

2016 ◽  
Vol 44 (1) ◽  
Author(s):  
Geetha Jose and Mercykutty Joseph
Keyword(s):  
Leaf Litter ◽  
Cover Crops ◽  
Cover Crop ◽  
Biological Activities ◽  
Rubber Plantations ◽  
Legume Cover Crops ◽  
Fungal Populations ◽  
Soil Pool ◽  
Natural Leaf ◽  
Different Sources

<p>Establishment of cover crop has been a standard scientific agronomic intervention in rubber (<em>Hevea brasiliensis</em>) plantations. Natural leaf fall in rubber plantations is an unaccounted phenomenon which also improves the physicochemical properties and biological activities of soil. A comparison of the decomposition of leaf litter from different sources in soil and the release of  utrients from them has been attempted in this study through a field experiment. Studies indicated that the degradation and release of nutrients to the soil pool was mainly decided by the leaf chemistry and degradability of the litter. Rubber litter had its own edge over other leguminous cover crop litter, in providing a sustained release of potassium, calcium and magnesium owing to its slow and steady mineralization rate compared to cover crops. Higher content of nutrients was recorded in degraded litter in comparison to fresh sources. Legume cover crops are capable of enhancing the bacterial and fungal populations in soil compared to nonleguminous crops in rubber plantations.</p>

scholarly journals Effects of tropical rainforest conversion to rubber plantation on soil quality in Hainan Island, China

2021 ◽  
Author(s):  
Rui Sun ◽  
Guoyu Lan ◽  
Chuan Yang ◽  
Zhixiang Wu ◽  
Banqian Chen ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Properties ◽  
Soil Quality ◽  
Tropical Rainforest ◽  
Hainan Island ◽  
Tropical Rainforests ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Cellulose Decomposition ◽  
Rubber Plantations

Abstract. Land-use changes can alter soil properties and thus affect soil quality. Our understanding of how forest conversion (from tropical rainforest to rubber plantations) affects soil properties and soil quality is limited. An ideal testing ground for analyzing such land-use change and its impacts is Hainan Island, the largest tropical island in China. Based on 21 soil physicochemical and biological properties, a soil quality index (SQI) employed principal component analysis to assess soil quality changes from the conversion of tropical rainforests to rubber plantations. The results showed that (i) soil available potassium, available phosphorus, microbial biomass carbon, cellulose decomposition, acid phosphatase, and urease were vital soil properties for soil quality assessment on Hainan Island. (ii) The SQI of rubber plantations decreased by 26.48 % compared to tropical rainforests, while four investigated soil properties (soil pH, total phosphorus, cellulose decomposition, and actinomyces) increased. (iii) The SQI of both the tropical rainforests and rubber plantations showed significant spatial differences, which, under tropical rainforests, was more sensitive to seasonal changes than those under rubber plantations. (iv) Structural equation modeling suggested that forest conversion directly impacted soil quality and, indirectly impacted soil qualities' spatial variation by their interaction with soil types and geographical positions. Overall, though the conversion of tropical rainforest to rubber plantation did not decrease all soil properties, the tropical rainforest with its high soil quality should be protected.

Species richness and guild composition in rubber plantations compared to secondary forest on Hainan Island, China

2013 ◽  
Vol 87 (5) ◽  
pp. 1117-1128 ◽  
Author(s):  
Shining Li ◽  
Fasheng Zou ◽  
Qiang Zhang ◽  
Frederick H. Sheldon
Keyword(s):  
Species Richness ◽  
Secondary Forest ◽  
Hainan Island ◽  
Rubber Plantations ◽  
Guild Composition

scholarly journals Identifying Establishment Year and Pre-Conversion Land Cover of Rubber Plantations on Hainan Island, China Using Landsat Data during 1987–2015

2018 ◽  
Vol 10 (8) ◽  
pp. 1240 ◽  
Author(s):  
Bangqian Chen ◽  
Xiangming Xiao ◽  
Zhixiang Wu ◽  
Tin Yun ◽  
Weili Kou ◽  
...  
Keyword(s):  
Land Cover ◽  
Best Management Practices ◽  
Management Practices ◽  
Rubber Tree ◽  
Hainan Island ◽  
Stand Age ◽  
Rubber Plantation ◽  
Land Cover Types ◽  
Rubber Plantations ◽  
Evergreen Forests

Knowing the stand age of rubber tree (Hevea brasiliensis) plantations is vitally important for best management practices, estimations of rubber latex yields, and carbon cycle studies (e.g., biomass, carbon pools, and fluxes). However, the stand age (as estimated from the establishment year of rubber plantation) is not available across large regions. In this study, we analyzed Landsat time series images from 1987–2015 and developed algorithms to identify (1) the establishment year of rubber plantations; and (2) the pre-conversion land cover types, such as old rubber plantations, evergreen forests, and cropland. Exposed soil during plantation establishment and linear increases in canopy closure during non-production periods (rubber seedling to mature plantation) were used to identify the establishment year of rubber plantations. Based on the rubber plantation map for 2015 (overall accuracy = 97%), and 1981 Landsat images since 1987, we mapped the establishment year of rubber plantations on Hainan Island (R2 = 0.85/0.99, and RMSE = 2.34/0.54 years at pixel/plantation scale). The results show that: (1) significant conversion of croplands and old rubber plantations to new rubber plantations has occurred substantially in the northwest and northern regions of Hainan Island since 2000, while old rubber plantations were mainly distributed in the southeastern inland strip; (2) the pattern of rubber plantation expansion since 1987 consisted of fragmented plantations from smallholders, and there was no tendency to expand towards a higher altitude and steep slope regions; (3) the largest land source for new rubber plantations since 1988 was old rubber plantations (1.26 × 105 ha), followed by cropland (0.95 × 105 ha), and evergreen forests (0.68 × 105 ha). The resultant algorithms and maps of establishment year and pre-conversion land cover types are likely to be useful in plantation management, and ecological assessments of rubber plantation expansion in China.

scholarly journals Evaluation of HRCLDAS and ERA5 Datasets for Near-Surface Wind over Hainan Island and South China Sea

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 766
Author(s):  
Yi Jiang ◽  
Shuai Han ◽  
Chunxiang Shi ◽  
Tao Gao ◽  
Honghui Zhen ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Surface Wind ◽  
Hainan Island ◽  
The South China Sea ◽  
Wind Data ◽  
The South ◽  
Near Surface ◽  
China Sea

Near-surface wind data are particularly important for Hainan Island and the South China Sea, and there is a wide range of wind data sources. A detailed understanding of the reliability of these datasets can help us to carry out related research. In this study, the hourly near-surface wind data from the High-Resolution China Meteorological Administration (CMA) Land Data Assimilation System (HRCLDAS) and the fifth-generation ECMWF atmospheric reanalysis data (ERA5) were evaluated by comparison with the ground automatic meteorological observation data for Hainan Island and the South China Sea. The results are as follows: (1) the HRCLDAS and ERA5 near-surface wind data trend was basically the same as the observation data trend, but there was a smaller bias, smaller root-mean-square errors, and higher correlation coefficients between the near-surface wind data from HRCLDAS and the observations; (2) the quality of HRCLDAS and ERA5 near-surface wind data was better over the islands of the South China Sea than over Hainan Island land. However, over the coastal areas of Hainan Island and island stations near Sansha, the quality of the HRCLDAS near-surface wind data was better than that of ERA5; (3) the quality of HRCLDAS near-surface wind data was better than that of ERA5 over different types of landforms. The deviation of ERA5 and HRCLDAS wind speed was the largest along the coast, and the quality of the ERA5 wind direction data was poorest over the mountains, whereas that of HRCLDAS was poorest over hilly areas; (4) the accuracy of HRCLDAS at all wind levels was higher than that of ERA5. ERA5 significantly overestimated low-grade winds and underestimated high-grade winds. The accuracy of HRCLDAS wind ratings over the islands of the South China Sea was significantly higher than that over Hainan Island land, especially for the higher wind ratings; and (5) in the typhoon process, the simulation of wind by HRCLDAS was closer to the observations, and its simulation of higher wind speeds was more accurate than the ERA5 simulations.

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