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 Stretching the Habitat Envelope: Insectivorous Bat Guilds Can Use Rubber Plantations, but Need Understorey Vegetation and Forest Buffers

2021 ◽  
Vol 2 ◽  
Author(s):  
Kadambari Deshpande ◽  
Nachiket Kelkar ◽  
Jagdish Krishnaswamy ◽  
Mahesh Sankaran
Keyword(s):  
Land Cover ◽  
Management Practices ◽  
Forest Cover ◽  
Foraging Strategies ◽  
Insectivorous Bats ◽  
Understorey Vegetation ◽  
Land Cover Types ◽  
Rubber Plantations ◽  
Bat Activity ◽  
Western Ghats Of India

Effects of land-cover change on insectivorous bat activity can be negative, neutral or positive, depending on foraging strategies of bats. In tropical agroforestry systems with high bat diversity, these effects can be complex to assess. We investigated foraging habitat use by three insectivorous bat guilds in forests and rubber plantations in the southern Western Ghats of India. Specifically, we monitored acoustic activity of bats in relation to (1) land-cover types and vegetation structure, and (2) plantation management practices. We hypothesized that activity of open-space aerial (OSA) and edge-space aerial (ESA) bat guilds would not differ; but narrow-space, flutter-detecting (NSFD) bat guild activity would be higher, in structurally heterogeneous forest habitats than monoculture rubber plantations. We found that bat activity of all guilds was highest in areas with high forest cover and lowest in rubber plantations. Higher bat activity was associated with understorey vegetation in forests and plantations, which was expected for NSFD bats, but was a surprise finding for OSA and ESA bats. Within land-cover types, open areas and edge-habitats had higher OSA and ESA activity respectively, while NSFD bats completely avoided open habitats. In terms of management practices, intensively managed rubber plantations with regular removal of understorey vegetation had the lowest bat activity for all guilds. Intensive management can undermine potential ecosystem services of insectivorous bats (e.g., insect pest-control in rubber plantations and surrounding agro-ecosystems), and magnify threats to bats from human disturbances. Low-intensity management and maintenance of forest buffers around plantations can enable persistence of insectivorous bats in tropical forest-plantation landscapes.

scholarly journals Spatiotemporal variation of bacterial water quality and the relationship with pasture land cover

2017 ◽  
Vol 15 (6) ◽  
pp. 839-848 ◽  
Author(s):  
Erin E. Scott ◽  
Mansoor D. K. Leh ◽  
Brian E. Haggard
Keyword(s):  
Water Quality ◽  
Land Cover ◽  
Best Management Practices ◽  
Management Practices ◽  
The United States ◽  
Illinois River ◽  
Health Concern ◽  
E Coli ◽  
Pasture Land ◽  
The Relationship

Abstract Pathogens are a major cause of water quality impairment and public health concern world-wide. In the United States, each state is tasked with developing water quality standards (WQS) to protect the designated use(s) of waterbodies. Several streams in the Illinois River Watershed in northwest Arkansas are currently listed as impaired due to elevated levels of pathogens. Our objective was to evaluate Escherichia coli (E. coli) numbers at 29 stream sites, compare these numbers to the applicable WQS, and investigate the relationship between E. coli numbers and land cover variables. E. coli numbers in samples collected at most sites were within allowable limits, although there were several instances of violations of the WQS. Violations were variable from year to year at some sites, and elevated levels of E. coli were spatially localized during baseflow. Violations also were positively related to pasture land cover in the drainage area, and particularly within the riparian buffer area. This relationship was non-linear, or threshold based, where there was a significant increase in the mean E. coli exceedances when riparian pasture land cover was greater than approximately 50%. These results can be used to identify specific stream reaches where E. coli numbers might be elevated and the implementation of best management practices can be geographically targeted.

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.

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.

scholarly journals Developing Multi-Source Indices to Discriminate between Native Tropical Forests, Oil Palm and Rubber Plantations in Indonesia

2021 ◽  
Vol 14 (1) ◽  
pp. 3
Author(s):  
Inggit Lolita Sari ◽  
Christopher J. Weston ◽  
Glenn J. Newnham ◽  
Liubov Volkova
Keyword(s):  
Land Cover ◽  
Oil Palm ◽  
Forest Monitoring ◽  
Rubber Plantation ◽  
Native Forest ◽  
Landsat 8 ◽  
Ground Truth Data ◽  
Rubber Plantations ◽  
Radar Images ◽  
Land Cover Maps

Over the last 18 years, Indonesia has experienced significant deforestation due to the expansion of oil palm and rubber plantations. Accurate land cover maps are essential for policymakers to track and manage land change to support sustainable forest management and investment decisions. An automatic digital processing (ADP) method is currently used to develop land cover change maps for Indonesia, based on optical imaging (Landsat). Such maps produce only forest and non-forest classes, and often oil palm and rubber plantations are misclassified as native forests. To improve accuracy of these land cover maps, this study developed oil palm and rubber plantation discrimination indices using the integration of Landsat-8 and synthetic aperture radar Sentinel-1 images. Sentinel-1 VH and VV difference (>7.5 dB) and VH backscatter intensity were used to discriminate oil palm plantations. A combination of Landsat-8 NDVI, NDMI with Sentinel-1 VV and VH were used to discriminate rubber plantations. The improved map produced four land cover classes: native forest, oil palm plantation, rubber plantation, and non-forest. High-resolution SPOT 6/7 imagery and ground truth data were used for validation of the new classified maps. The map had an overall accuracy of 92%; producer’s accuracy for all classes was higher than 90%, except for rubber (65%), and user’s accuracy was over 80% for all classes. These results demonstrate that indices developed from a combination of optical and radar images can improve our ability to discriminate between native forest and oil palm and rubber plantations in the tropics. The new mapping method will help to support Indonesia’s national forest monitoring system and inform monitoring of plantation expansion.

scholarly journals High-Precision Stand Age Data Facilitate the Estimation of Rubber Plantation Biomass: A Case Study of Hainan Island, China

2020 ◽  
Vol 12 (23) ◽  
pp. 3853
Author(s):  
Bangqian Chen ◽  
Tin Yun ◽  
Jun Ma ◽  
Weili Kou ◽  
Hailiang Li ◽  
...  
Keyword(s):  
Regression Model ◽  
Forest Biomass ◽  
Hainan Island ◽  
Stand Age ◽  
Biomass Estimation ◽  
Tropical Region ◽  
Rubber Plantation ◽  
Large Area ◽  
Biomass Density ◽  
Scatter Plots

Rubber (Hevea brasiliensis Muell.) plantations constitute one of the most important agro-ecosystems in the tropical region of China and Southeast Asia, playing an important role in the carbon budget there. Accurately obtaining their biomass over a large area is challenging because of difficulties in acquiring the Diameter at Breast Height (DBH) through remote sensing and the problem of biomass saturation. The stand age, which is closely related to the forest biomass, was proposed for biomass estimation in this study. A stand age map at an annual scale for Hainan Island, which is the second largest natural rubber production base in China, was generated using all Landsat and Sentinel-2 (LS2) data (1987–2017). Scatter plots and the correlation coefficient method were used to explore the relationship (e.g., biomass saturation) between rubber biomass and different LS2-based variables. Subsequently, a regression model fitted with the stand age (R2 = 0.96) and a Random Forest (RF) model parameterizing with LS2-based variables and/or the stand age were respectively employed to estimate rubber biomass for Hainan Island. The results show that rubber biomass was saturated around 65 Mg/ha with all LS2-based variables. The regression model estimated biomass accurately (R2 = 0.79 and Root Mean Square Error (RMSE) = 14.00 Mg/ha) and eliminated the saturation problem significantly. In addition to LS2-based variables, adding a stand age parameter to the RF models was found to significantly improve the prediction accuracy (R2 = 0.82–0.96 and RMSE = 4.08–10.59 Mg/ha, modeling using samples of different biomass sizes). However, all RF models overestimated the biomass of young plantations and underestimated the biomass of old plantations. A hybrid model integrating the optimal results of RF and regression models reduced estimation bias and generated the best performance (R2 = 0.83 and RMSE = 12.48 Mg/ha). The total rubber biomass of Hainan Island in 2017 was about 5.40 × 107 Mg. The northward and westward expansions after 2000 had great impact on the biomass distribution, leading to a higher biomass density for the inland coastal strip from south to northeast and a lower biomass density in the northern and western regions.

scholarly journals RZ-TRADEOFF: A New Model to Estimate Riparian Water and Air Quality Functions

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 769 ◽  
Author(s):  
Hassanzadeh ◽  
Vidon ◽  
Gold ◽  
Pradhanang ◽  
Lowder
Keyword(s):  
Land Use ◽  
Air Quality ◽  
Land Cover ◽  
Water Table ◽  
Best Management Practices ◽  
Management Practices ◽  
Overland Flow ◽  
Subsurface Flow ◽  
Riparian Zones ◽  
The Impact

Riparian zones are often used as best management practices due to their ability to remove nitrate (NO3−) from subsurface flow. Research suggests that beyond local biogeochemical controls, the impact of riparian zones on nitrogen removal and other functions, such as phosphorus dynamics and greenhouse gas emissions, largely depends on land-use/land-cover, hydrogeomorphology, and weather. In this study, we therefore present RZ-TRADEOFF, a novel and easily applicable model that connects multiple riparian functions and characteristics (NO3− and phosphate (PO43−), concentration and removal in subsurface flow, total phosphorus (TP) removal in overland flow, nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions, water table) to landscape hydrogeomorphic characteristics, weather, and land-cover/land-use. RZ-TRADEOFF was developed with data from past studies and digital databases, and validated with data collected from the literature. Three functions (water table, PO43− and CO2) were observed to be significantly influenced by climate/weather, while the others were primarily influenced by hydrogeomorphology and land use. The percent bias and normalized root mean square error respectively were −3.35% and 0.28 for water table, 16.00% and 0.34 for NO3− concentration, −7.83% and 20.82 for NO3− removal, 6.64% and 0.35 for PO43− concentration, 2.55% and 0.17 for TP removal, 40.33% and 0.23 for N2O, 72.68% and 0.18 for CH4, and −34.98% and 0.91 for CO2. From a management standpoint, RZ-TRADEOFF significantly advances our ability to predict multiple water and air quality riparian functions using easily accessible data over large areas of the landscape due to its scalability.

scholarly journals Effect of high-frequency tapping system on latex yield, tapping panel dryness, and biochemistry of young hillside tapping rubber

2020 ◽  
Vol 48 (4) ◽  
pp. 2359-2367
Author(s):  
Raweerat RUKKHUN ◽  
Kesinee IAMSAARD ◽  
Sayan SDOODEE ◽  
Nipon MAWAN ◽  
Nuttapon KHONGDEE
Keyword(s):  
High Frequency ◽  
Rubber Tree ◽  
Dry Weight ◽  
Inorganic Phosphorus ◽  
Rubber Plantation ◽  
Rubber Plantations ◽  
Yield Production ◽  
Highly Correlated ◽  
Tapping Panel Dryness ◽  
Latex Yield

The objective of this study was to examine the effect of high-frequency tapping system (1/3S 3d/4) on latex yield, biochemistry and its impact on the Tapping Panel Dryness (TPD) of young RRIM600 hillside tapping rubber. The experiment was conducted at three different hillside rubber plantations (NM 1 - 3) at Na-Mom district, Song Khla province, Thailand. Eight-year-old rubber RRIM 600 clones was used in the experiment starting from 2008 until 2009. The rubber trees were investigated for latex yield production, bark consumption, and TPD. In addition, latex diagnosis (sucrose, inorganic phosphorus (Pi), and thiol levels) was measured. The results demonstrated that high-frequency tapping system positively affected the rubber latex yield formation. However, site-specific condition of rubber plantation altered latex yield production. NM 3 provided the highest latex yield (fresh and dry weight) as compared to other plantations. Tapping frequency was highly correlated to latex yield (fresh and dry weights) in all investigated rubber plantations (R2 > 0.75). Using high-frequency tapping system increased bark consumption and stimulated TPD. Moreover, results of latex diagnosis (sucrose, Pi, and thiol levels) showed relatively unhealthy rubber tree as impacted by high-frequency tapping system. Therefore, the farmer should consider it for better decision-making for tapping system application.

scholarly journals EMISI GAS RUMAH KACA DI PERKEBUNAN KARET

2016 ◽  
Vol 35 (2) ◽  
pp. 157
Author(s):  
Priyo Adi Nugroho
Keyword(s):  
Organic Matter ◽  
Best Management Practices ◽  
Carbon Emission ◽  
Management Practices ◽  
Agricultural Sector ◽  
Soil Tillage ◽  
Rubber Plantation ◽  
Time Of Application ◽  
Research Consortium ◽  
Carbon Dioxide Co2

Carbon dioxide (CO2) and nitrous oxide (N2O) and methane (CH4) are three of the major greenhouse gas (GHG). Agricultural sector accounts for 10-14% of global athropogenic GHGs. The research of GHGs in rubber plantation has been started in several rubber producer countries including Indonesia however the progress is not as fast as in other agricultural commodities. Carbon stock and carbon balance in rubber plantation is the trending research topic. Biometric and eddy coveriance are the two methods that are used for investigating carbon emission. The results of some study using those two methods indicate that the similar result i.e. the amount carbon that is released by rubber plantation ecosystem is tended to be smaller than carbon absorption. The amount of CO2 that absorbed by rubber plantation is approximately 29-40 tons CO2 ha/year. Commonly the previous studies are mostly conducted in establish area, which mean the study is not designed with some treatments such as fertilizer and organic matter dosage, time of application, soil tillage. The deeply study of carbon emission, related to field management to carry out the best management practices and environmental friendly is still needed. The similar study concerning other gas like N2O in rubber plantation is also important to be conducted. It is due to the application of nitrogen fertilizer and organic matter in rubber plantation is high enough. There are some opportunities to conduct research consortium with other research institutions and universities in order to solve the high cost in GHGs research.

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