scholarly journals Expanding Rubber Plantations in Southern China: Evidence for Hydrological Impacts

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 651 ◽  
Author(s):  
Xing Ma ◽  
Guillaume Lacombe ◽  
Rhett Harrison ◽  
Jianchu Xu ◽  
Meine van Noordwijk
Keyword(s):  
Southern China ◽  
Rainfall Variability ◽  
Rubber Tree ◽  
Dry Season ◽  
Base Flow ◽  
Balance Model ◽  
Tree Plantations ◽  
Watershed Scale ◽  
Rubber Plantations ◽  
Local Water

While there is increasing evidence concerning the detrimental effects of expanding rubber plantations on biodiversity and local water balances, their implications on regional hydrology remain uncertain. We studied a mesoscale watershed (100 km2) in the Xishuangbanna prefecture, Yunnan Province, China. The influence of land-cover change on streamflow recorded since 1992 was isolated from that of rainfall variability using cross-simulation matrices produced with the monthly lumped conceptual water balance model GR2M. Our results indicate a statistically significant reduction in wet and dry season streamflow from 1992 to 2002, followed by an insignificant increase until 2006. Analysis of satellite images from 1992, 2002, 2007, and 2010 shows a gradual increase in the areal percentage of rubber tree plantations at the watershed scale. However, there were marked heterogeneities in land conversions (between forest, farmland, grassland, and rubber tree plantations), and in their distribution across elevations and slopes, among the studied periods. Possible effects of this heterogeneity on hydrological processes, controlled mainly by infiltration and evapotranspiration, are discussed in light of the hydrological changes observed over the study period. We suggest pathways to improve the eco-hydrological functionalities of rubber tree plantations, particularly those enhancing dry-season base flow, and recommend how to monitor them.

scholarly journals Seasonality of pathogenic fungi in mites of rubber tree plantations adjacent to fragments of Cerrado

2008 ◽  
Vol 68 (3) ◽  
pp. 535-538 ◽  
Author(s):  
PR. Demite ◽  
RJF. Feres
Keyword(s):  
Rainy Season ◽  
Rubber Tree ◽  
Pathogenic Fungi ◽  
Dry Season ◽  
Tree Plantations ◽  
Tree Plantation ◽  
Cerrado Vegetation ◽  
Hirsutella Thompsonii

Fungi are the most frequently observed pathogens of mite populations, helping to control them on different crops. Twenty-five samples of leaves were collected from rubber tree plantations adjacent to two fragments of Cerrado vegetation. Each rubber tree plantation had 25 plants selected for sampling and seven leaves from around each tree top were collected up to seven to eight meters above ground. Approximately 250 individuals of Calacarus heveae Feres, Phyllocoptruta seringueirae Feres, and Tenuipalpus heveae Baker, collected randomly, were mounted from each plantation. Hirsutella thompsoni Fisher was observed on all three mites and T. heveae was the most infected species. The highest infestation levels occurred from November to February (rainy season). In the dry season, infestation levels were below 5%. Hirsutella thompsonii has potential to be used as mycoacaricide during the rainy season.

scholarly journals Genomic Characteristics and Comparative Genomics Analysis of Two Chinese Corynespora cassiicola Strains Causing Corynespora Leaf Fall (CLF) Disease

2021 ◽  
Vol 7 (6) ◽  
pp. 485
Author(s):  
Boxun Li ◽  
Yang Yang ◽  
Jimiao Cai ◽  
Xianbao Liu ◽  
Tao Shi ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Single Molecule ◽  
Rubber Tree ◽  
Gene Families ◽  
Gene Clusters ◽  
The Philippines ◽  
Tree Plantations ◽  
Comparative Genomic ◽  
Corynespora Cassiicola ◽  
Leaf Fall

Rubber tree Corynespora leaf fall (CLF) disease, caused by the fungus Corynespora cassiicola, is one of the most damaging diseases in rubber tree plantations in Asia and Africa, and this disease also threatens rubber nurseries and young rubber plantations in China. C. cassiicola isolates display high genetic diversity, and virulence profiles vary significantly depending on cultivar. Although one phytotoxin (cassicolin) has been identified, it cannot fully explain the diversity in pathogenicity between C. cassiicola species, and some virulent C. cassiicola strains do not contain the cassiicolin gene. In the present study, we report high-quality gapless genome sequences, obtained using short-read sequencing and single-molecule long-read sequencing, of two Chinese C. cassiicola virulent strains. Comparative genomics of gene families in these two stains and a virulent CPP strain from the Philippines showed that all three strains experienced different selective pressures, and metabolism-related gene families vary between the strains. Secreted protein analysis indicated that the quantities of secreted cell wall-degrading enzymes were correlated with pathogenesis, and the most aggressive CCP strain (cassiicolin toxin type 1) encoded 27.34% and 39.74% more secreted carbohydrate-active enzymes (CAZymes) than Chinese strains YN49 and CC01, respectively, both of which can only infect rubber tree saplings. The results of antiSMASH analysis showed that all three strains encode ~60 secondary metabolite biosynthesis gene clusters (SM BGCs). Phylogenomic and domain structure analyses of core synthesis genes, together with synteny analysis of polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) gene clusters, revealed diversity in the distribution of SM BGCs between strains, as well as SM polymorphisms, which may play an important role in pathogenic progress. The results expand our understanding of the C. cassiicola genome. Further comparative genomic analysis indicates that secreted CAZymes and SMs may influence pathogenicity in rubber tree plantations. The findings facilitate future exploration of the molecular pathogenic mechanism of C. cassiicola.

scholarly journals Nutrient cycling in a RRIM 600 clone rubber plantation

2003 ◽  
Vol 60 (2) ◽  
pp. 353-357 ◽  
Author(s):  
Marcos Roberto Murbach ◽  
Antonio Enedi Boaretto ◽  
Takashi Muraoka ◽  
Euclides Caxambu Alexandrino de Souza
Keyword(s):  
Nutrient Cycling ◽  
Rubber Tree ◽  
Nutrient Content ◽  
Nutrient Loss ◽  
Tree Plantations ◽  
Rubber Plantation ◽  
Rubber Latex ◽  
Nutrient Retranslocation ◽  
One Year ◽  
K Fertilization

Few reports have been presented on nutrient cycling in rubber tree plantations (Hevea brasiliensis Muell. Arg.). This experiment was carried out to evaluate: the effect of K rates on the amount of nutrients transfered to the soil in a 13-year old Hevea brasilensis RRIM 600 clone plantation, nutrient retranslocation from the leaves before falling to the soil, and nutrient loss by dry rubber export. The experiment started in 1998 and potassium was applied at the rates of 0, 40, 80 and 160 kg ha-1 of K2O under the crowns of 40 rubber trees of each plot. Literfall collectors, five per plot, were randomly distributed within the plots under the trees. The accumulated literfall was collected monthly during one year. The coagulated rubber latex from each plot was weighed, and samples were analyzed for nutrient content. Increasing K fertilization rates also increased the K content in leaf literfall. Calcium and N were the most recycled leaf nutrients to the soil via litterfall. Potassium, followed by P were the nutrients with the highest retranslocation rates. Potassium was the most exported nutrient by the harvested rubber, and this amount was higher than that transfered to the soil by the leaf literfall.

scholarly journals Evaluation of Water-Storage and Water-Saving Potential for Paddy Fields in Gaoyou, China

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1176 ◽  
Author(s):  
Chuanjuan Wang ◽  
Shaoli Wang ◽  
Haorui Chen ◽  
Jiandong Wang ◽  
Yuan Tao ◽  
...  
Keyword(s):  
Southern China ◽  
Financial Burden ◽  
Water Shortage ◽  
Water Saving ◽  
Paddy Fields ◽  
Balance Model ◽  
Agricultural Water ◽  
Average Water ◽  
Agricultural Water Resources ◽  
Water Fee

In China, the stress on agricultural water resources is becoming increasingly severe. In response, a range of water-saving irrigation (WSI) policies and practices have been promoted to improve irrigation efficiency. In this study, a water-balance model in paddy fields was calibrated and validated using a 2-year field experimental dataset collected from an irrigated area in Gaoyou, China, in 2014–2015. The model was used to assess the effects of WSI practices and provides options for implementing water-price reforms. Results show that paddy fields effectively retain rainfall with utilization rates greater than 70% for both shallow wet irrigation (SWI) and shallow humidity-regulated irrigation (SHRI) scenarios. The estimated average water-saving rates from 1960 to 2015 using SWI and SHRI are 33.7% and 43%, respectively, which represent considerable reductions in water consumption. The benefits of WSI practices combined with water management policies are also evident. For example, conversion of irrigation water to industrial water yields a 3-year average water fee of 205.2 yuan/ha using SWI and 20.6 yuan/ha using SHRI, considerably reducing farmers’ financial burden for agricultural water supplies. In conclusion, we recommend the adoption of SWI and SHRI practices in southern China as a means of partially alleviating China’s water-shortage problem.

Carbon stock in rubber tree plantations in Western Ghana and Mato Grosso (Brazil)

2008 ◽  
Vol 255 (7) ◽  
pp. 2347-2361 ◽  
Author(s):  
J.B. Wauters ◽  
S. Coudert ◽  
E. Grallien ◽  
M. Jonard ◽  
Q. Ponette
Keyword(s):  
Carbon Stock ◽  
Rubber Tree ◽  
Tree Plantations ◽  
Mato Grosso

Watershed-scale distributions of heavy metals in the hyporheic zones of a heavily polluted Maozhou River watershed, southern China

Chemosphere ◽  
2020 ◽  
Vol 239 ◽  
pp. 124773 ◽  
Author(s):  
Kai Yu ◽  
Yanhua Duan ◽  
Peng Liao ◽  
Lin Xie ◽  
Qianqian Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Southern China ◽  
Watershed Scale ◽  
River Watershed ◽  
Hyporheic Zones

Rivers as groundwater-dependent ecosystems: a review of degrees of dependency, riverine processes and management implications

2006 ◽  
Vol 54 (2) ◽  
pp. 133 ◽  
Author(s):  
A. J. Boulton ◽  
P. J. Hancock
Keyword(s):  
Base Flow ◽  
Management Approach ◽  
River Channels ◽  
Management Implications ◽  
River Types ◽  
Groundwater Dependent Ecosystems ◽  
Management Plans ◽  
Explicit Recognition ◽  
Local Water ◽  
Chemical Conditions

Many rivers are classified as groundwater-dependent ecosystems (GDEs), owing to the contribution of groundwater to their base flow. However, there has been little explicit recognition of the way groundwater influences riverine biota or processes, how degrees of ecological dependency may vary, and the management implications of this dependency. The permeable beds and banks of these GDEs where surface water and groundwater exchange are termed ‘hyporheic zones’. They are often inhabited by invertebrates, with varying reliance on groundwater, although the ecological roles of these invertebrates are little known. Upwelling hyporheic water can promote surface primary productivity, influence sediment microbial activity, and affect organic matter decomposition. In many intermittent streams, variable groundwater inputs alter the duration of flow or water permanence, and the duration and timing of these largely govern the biota and rates of many ecosystem processes (e.g. leaf decomposition). Not only is the physical presence of water important, thermal and chemical conditions arising from groundwater inputs also have direct and indirect effects on riverine biota and rates or types of in-stream processes. Differing degrees of dependency of rivers on groundwater mediate all these influences, and may change over time and in response to human activities. Alteration of groundwater inputs through extraction from riparian wells or changes in local water table have an impact on these GDEs, and some current management plans aim to restrict groundwater extraction from near permeable river channels. However, these are often ‘blanket’ restrictions and the mechanisms of GDE dependency or timing of groundwater requirements are poorly understood, hampering refinement of this management approach. More effective management of these GDEs into the future can result only from a better understanding of the mechanisms of the dependency, how these vary among river types and what in-stream changes might be predicted from alteration of groundwater inputs.

scholarly journals Higher runoff and soil detachment in rubber tree plantations compared to annual cultivation is mitigated by ground cover in steep mountainous Thailand

CATENA ◽  
2020 ◽  
Vol 189 ◽  
pp. 104472 ◽  
Author(s):  
Margot Neyret ◽  
Henri Robain ◽  
Anneke de Rouw ◽  
Jean-Louis Janeau ◽  
Thibaut Durand ◽  
...  
Keyword(s):  
Rubber Tree ◽  
Ground Cover ◽  
Tree Plantations

scholarly journals Quantification of Temporal Variations in Base Flow Index Using Sporadic River Data: Application to the Bua Catchment, Malawi

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 901 ◽  
Author(s):  
Laura Kelly ◽  
Robert M. Kalin ◽  
Douglas Bertram ◽  
Modesta Kanjaye ◽  
Macpherson Nkhata ◽  
...  
Keyword(s):  
Water Resources ◽  
River Flow ◽  
Temporal Variations ◽  
Dry Season ◽  
Base Flow ◽  
Flow Index ◽  
Wet Season ◽  
Data Application ◽  
Base Flow Index ◽  
Long Term Trends

This study investigated how sporadic river datasets could be used to quantify temporal variations in the base flow index (BFI). The BFI represents the baseflow component of river flow which is often used as a proxy indicator for groundwater discharge to a river. The Bua catchment in Malawi was used as a case study, whereby the smoothed minima method was applied to river flow data from six gauges (ranging from 1953 to 2009) and the Mann-Kendall (MK) statistical test was used to identify trends in BFI. The results showed that baseflow plays an important role within the catchment. Average annual BFIs > 0.74 were found for gauges in the lower reaches of the catchment, in contrast to lower BFIs < 0.54 which were found for gauges in the higher reaches. Minimal difference between annual and wet season BFI was observed, however dry season BFI was >0.94 across all gauges indicating the importance of baseflow in maintaining any dry season flows. Long term trends were identified in the annual and wet season BFI, but no evidence of a trend was found in the dry season BFI. Sustainable management of the investigated catchment should, therefore, account for the temporal variations in baseflow, with special regard to water resources allocation within the region and consideration in future scheme appraisals aimed at developing water resources. Further, this demonstration of how to work with sporadic river data to investigate baseflow serves as an important example for other catchments faced with similar challenges.

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