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Vijayan D, Girindran R, Sam AS, Sathyan AR, Kaechele H. The large-scale expansion of rubber plantations in southern India: major impacts and the changing nature of drivers. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:356. [PMID: 38467961 PMCID: PMC10927887 DOI: 10.1007/s10661-024-12517-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 03/05/2024] [Indexed: 03/13/2024]
Abstract
This study investigates the major environmental and socio-economic impacts of an increase in the area of rubber plantations and the changing patterns of drivers of land use changes. Using a combination of geospatial techniques and socio-economic methods, we mainly analyzed the rate of increase in area under rubber plantations, the major impacts of land use changes, and the changing drivers of land use changes. Our results show that the area under rubber plantations has increased significantly within the study area, with the area under rubber plantations increasing from 30 to 74% of the total area within five decades. Impact assessment of land use changes based on household surveys showed significant improvement in the socio-economic conditions of the farmers, however, at the expense of severe environmental degradation. Our results also indicate that while areas under rubber plantations continue to increase, the drivers of land use changes have changed over time. Furthermore, it has been observed that in the past, many interventions prioritized social and economic development and placed less emphasis on the ecological stability of the region. Perceptions of farmers revealed that the effects of ecological fragility already affected the economic robustness of the whole area. Therefore, we conclude that government interventions to support additional rubber cultivation should also focus on ecosystem stabilization in order to minimize the risk of an ecological catastrophe that would significantly affect the economic prosperity of the region.
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Affiliation(s)
- Dhanya Vijayan
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374, Müncheberg, Germany.
| | - Renoy Girindran
- School of Geography, University of Nottingham, Nottingham, NG7 2, UK
| | - Anu Susan Sam
- Kerala Agricultural University, Regional Agricultural Research Station, Kumarakom, Kerala, 686563, India
| | | | - Harald Kaechele
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374, Müncheberg, Germany
- Eberswalde University for Sustainable Development, Schicklerstrasse 5, 16225, Eberswalde, Germany
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Waite PA, Leuschner C, Delzon S, Triadiati T, Saad A, Schuldt B. Plasticity of wood and leaf traits related to hydraulic efficiency and safety is linked to evaporative demand and not soil moisture in rubber (Hevea brasiliensis). TREE PHYSIOLOGY 2023; 43:2131-2149. [PMID: 37707940 DOI: 10.1093/treephys/tpad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/15/2023]
Abstract
The predicted increase of drought intensity in South-East Asia has raised concern about the sustainability of rubber (Hevea brasiliensis Müll. Arg.) cultivation. In order to quantify the degree of phenotypic plasticity in this important tree crop species, we analysed a set of wood and leaf traits related to the hydraulic safety and efficiency in PB260 clones from eight small-holder plantations in Jambi province, Indonesia, representing a gradient in local microclimatic and edaphic conditions. Across plots, branch embolism resistance (P50) ranged from -2.14 to -2.58 MPa. The P50 and P88 values declined, and the hydraulic safety margin increased, with an increase in the mean annual vapour pressure deficit (VPD). Among leaf traits, only the changes in specific leaf area were related to the differences in evaporative demand. These variations of hydraulic trait values were not related to soil moisture levels. We did not find a trade-off between hydraulic safety and efficiency, but vessel density (VD) emerged as a major trait associated with both safety and efficiency. The VD, and not vessel diameter, was closely related to P50 and P88 as well as to specific hydraulic conductivity, the lumen-to-sapwood area ratio and the vessel grouping index. In conclusion, our results demonstrate some degree of phenotypic plasticity in wood traits related to hydraulic safety in this tropical tree species, but this is only in response to the local changes in evaporative demand and not soil moisture. Given that VPD may increasingly limit plant growth in a warmer world, our results provide evidence of hydraulic trait changes in response to a rising evaporative demand.
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Affiliation(s)
- Pierre-André Waite
- Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Straße 7, Tharandt 01737, Germany
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
| | - Christoph Leuschner
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
| | - Sylvain Delzon
- Department of Biodiversity, Genes, and Communities (BIOGECO), Institut National de Recherche pour Agriculture, Alimentation et Environnement (INRAE), Université Bordeaux, Bat. 2 Allée Geoffroy St-Hilaire, Pessac 33615, France
| | - Triadiati Triadiati
- Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor IPB University, Darmaga Campus, Bogor 16680, Indonesia
| | - Asmadi Saad
- Department of Soil Science, University of Jambi, Jalan Raya Jambi Muara Bulian KM 15 Mandalo Indah, Jambi, Sumatra 36361, Indonesia
| | - Bernhard Schuldt
- Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Straße 7, Tharandt 01737, Germany
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
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Wei L, Qiu Z, Zhou G, Zuecco G, Liu Y, Wen Y. Soil water hydraulic redistribution in a subtropical monsoon evergreen forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155437. [PMID: 35476947 DOI: 10.1016/j.scitotenv.2022.155437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/07/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Hydraulic redistribution (HR), which is the passive movement of water through plant roots from wet to dry soil due to the water gradient, is important for plant physiology and ecohydrological processes. However, our poor knowledge on HR in the humid monsoon climate zone hampers the understanding of the interactions between vegetation and soil water during frequent droughts in evergreen forests. Thus, 5 years (2011-2015) of data, including meteorological parameters and soil moisture content at depths of 10, 30, 50, and 100 cm in soil profiles, were compared at one evergreen broad-leaved forest and at one clear-cutting forest site in south China. Analyses of soil moisture dynamics show that HR was frequently triggered within the depth of 30 cm at the evergreen broad-leaved forest, while (if any) was less visible at the clear-cutting forest site. The daily averaged magnitude of redistributed soil water reached the maximum of 0.81 mm/d. The HR mainly occurred during the monsoon dry season (i.e., from October to March of the following year), possibly indicating a different cause, i.e., asynchronous variations in rainfall and plant water use shape the seasonal patterns of soil water HR, compared to other humid zones. During the study period when HR occurred, the average daily HR in the soil profiles replenished approximately 34-50% of the water consumption in the 0-30 cm soil layer. The simulation results of a distributed hydrology-soil-vegetation model incorporating a HR scheme indicate that evapotranspiration enhanced during drought periods when HR occurred. In the future climate change context, comprehensive investigations on the water fluxes in the atmosphere-vegetation-soil continuum are needed to fully understand the effects of HR on the physiological responses of plants and on the water cycle.
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Affiliation(s)
- Lezhang Wei
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Linköping University - Guangzhou University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou 510006, China
| | - Zhijun Qiu
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China.
| | - Guangyi Zhou
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China
| | - Giulia Zuecco
- Department of Land, Environment, Agriculture and Forestry, University of Padova, via dell'Università 16, 35020 Legnaro, PD, Italy
| | - Yu Liu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Linköping University - Guangzhou University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou 510006, China
| | - Ya Wen
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
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Sterling A, Rodríguez N, Clavijo-Arias EA, Claros-Loaiza YP, Salazar JCS. Dynamics of water-use efficiency and status in promising Hevea brasiliensis genotypes: implications for clonal selection. J RUBBER RES 2021. [DOI: 10.1007/s42464-021-00120-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zou X, Zhu X, Zhu P, Singh AK, Zakari S, Yang B, Chen C, Liu W. Soil quality assessment of different Hevea brasiliensis plantations in tropical China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 285:112147. [PMID: 33607560 DOI: 10.1016/j.jenvman.2021.112147] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/18/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Land degradation is a global problem caused by improper agricultural practices. In tropical China, the rubber (Hevea brasiliensis) plantations are predominantly practiced on forest-cleared lands, considering their sustainable land management potential compared to annual cropping. However, all rubber plantations may not have similar land management capacity. Soil quality index (SQI) can reveal the overall soil status with a single score, which is an efficient tool to evaluate the soil quality of each category of rubber plantations. We investigated 23 soil physical and chemical parameters of three categories of rubber plantations and a primary rainforest, and derived SQI based on these parameters. Soil samples were collected from a rubber monoculture (RM), a rubber-Camellia sinensis agroforestry (RT), a rubber-Dracaena cochinchinensis agroforestry (RD), and a primary rainforest (RF). The results showed that the SQI value of the RM decreased by 15.50% compared to the RF, with a significant degree of soil nutrient loss (18.90%). This indicates that monocultural rubber cultivation is causing land degradation to some extent. However, the SQI was significantly enhanced by rubber-based agroforestry practices (25.30% by RT and 33.10% by RD) compared to the RM, suggesting that polyculture practices are suitable to recover the soil quality in degraded agricultural lands. Moreover, the chemical parameters contributed more to the SQI than did the physical parameters, indicating that nutrient management is important in soil quality recovery. Overall, our results suggest that agroforestry should be preferred over monoculture in the rubber plantations for sustainable land management in tropical China.
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Affiliation(s)
- Xin Zou
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xiai Zhu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China.
| | - Peng Zhu
- College of Forestry, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Ashutosh Kumar Singh
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China.
| | - Sissou Zakari
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Laboratory of Hydraulics and Environmental Modeling (HydroModE-Lab), Faculté d'Agronomie, Université de Parakou, 03 BP 351, Parakou, Benin.
| | - Bin Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China.
| | - Chunfeng Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China.
| | - Wenjie Liu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China.
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6
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Expanding Rubber Plantations in Southern China: Evidence for Hydrological Impacts. WATER 2019. [DOI: 10.3390/w11040651] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
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.
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7
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Large Variation in Carbon Isotope Composition of Bulk Leaf Material of Rubber Trees from a Germplasm Collection: An Opportunity for Improving Water Use Efficiency in Breeding Programs. J RUBBER RES 2017. [DOI: 10.1007/bf03449142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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Wu J, Liu W, Chen C. Can intercropping with the world's three major beverage plants help improve the water use of rubber trees? J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12730] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junen Wu
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Menglun Yunnan 666303 China
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - Wenjie Liu
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Menglun Yunnan 666303 China
| | - Chunfeng Chen
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Menglun Yunnan 666303 China
- University of Chinese Academy of Sciences; Beijing 100049 China
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9
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Maeght JL, Gonkhamdee S, Clément C, Isarangkool Na Ayutthaya S, Stokes A, Pierret A. Seasonal Patterns of Fine Root Production and Turnover in a Mature Rubber Tree (Hevea brasiliensis Müll. Arg.) Stand- Differentiation with Soil Depth and Implications for Soil Carbon Stocks. FRONTIERS IN PLANT SCIENCE 2015; 6:1022. [PMID: 26640467 PMCID: PMC4661276 DOI: 10.3389/fpls.2015.01022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/05/2015] [Indexed: 05/17/2023]
Abstract
Fine root dynamics is a main driver of soil carbon stocks, particularly in tropical forests, yet major uncertainties still surround estimates of fine root production and turnover. This lack of knowledge is largely due to the fact that studying root dynamics in situ, particularly deep in the soil, remains highly challenging. We explored the interactions between fine root dynamics, soil depth, and rainfall in mature rubber trees (Hevea brasiliensis Müll. Arg.) exposed to sub-optimal edaphic and climatic conditions. A root observation access well was installed in northern Thailand to monitor root dynamics along a 4.5 m deep soil profile. Image-based measurements of root elongation and lifespan of individual roots were carried out at monthly intervals over 3 years. Soil depth was found to have a significant effect on root turnover. Surprisingly, root turnover increased with soil depth and root half-life was 16, 6-8, and only 4 months at 0.5, 1.0, 2.5, and 3.0 m deep, respectively (with the exception of roots at 4.5 m which had a half-life similar to that found between depths of 1.0 and 2.5 m). Within the first two meters of the soil profile, the highest rates of root emergence occurred about 3 months after the onset of the rainy season, while deeper in the soil, root emergence was not linked to the rainfall pattern. Root emergence was limited during leaf flushing (between March and May), particularly within the first two meters of the profile. Between soil depths of 0.5 and 2.0 m, root mortality appeared independent of variations in root emergence, but below 2.0 m, peaks in root emergence and death were synchronized. Shallow parts of the root system were more responsive to rainfall than their deeper counterparts. Increased root emergence in deep soil toward the onset of the dry season could correspond to a drought acclimation mechanism, with the relative importance of deep water capture increasing once rainfall ceased. The considerable soil depth regularly explored by fine roots, even though significantly less than in surface layers in terms of root length density and biomass, will impact strongly the evaluation of soil carbon stocks.
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Affiliation(s)
- Jean-Luc Maeght
- Institut de Recherche pour le Développement, UMR 242/iEES – Paris (IRD-UPMC-CNRS-UPEC-UDD-INRA)Bondy, France
- INRA, UMR-AMAPMontpellier, France
| | | | | | | | | | - Alain Pierret
- Institut de Recherche Pour le Développement, UMR IEES-Paris – Department of Agricultural Land Management (DALaM)Vientiane, Laos
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10
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Sopharat J, Gay F, Thaler P, Sdoodee S, Isarangkool Na Ayutthaya S, Tanavud C, Hammecker C, Do FC. A simple framework to analyze water constraints on seasonal transpiration in rubber tree (Hevea brasiliensis) plantations. FRONTIERS IN PLANT SCIENCE 2015; 5:753. [PMID: 25610443 PMCID: PMC4285198 DOI: 10.3389/fpls.2014.00753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/08/2014] [Indexed: 06/04/2023]
Abstract
Climate change and fast extension in climatically suboptimal areas threaten the sustainability of rubber tree cultivation. A simple framework based on reduction factors of potential transpiration was tested to evaluate the water constraints on seasonal transpiration in tropical sub-humid climates, according pedoclimatic conditions. We selected a representative, mature stand in a drought-prone area. Tree transpiration, evaporative demand and soil water availability were measured every day over 15 months. The results showed that basic relationships with evaporative demand, leaf area index and soil water availability were globally supported. However, the implementation of a regulation of transpiration at high evaporative demand whatever soil water availability was necessary to avoid large overestimates of transpiration. The details of regulation were confirmed by the analysis of canopy conductance response to vapor pressure deficit. The final objective of providing hierarchy between the main regulation factors of seasonal and annual transpiration was achieved. In the tested environmental conditions, the impact of atmospheric drought appeared larger importance than soil drought contrary to expectations. Our results support the interest in simple models to provide a first diagnosis of water constraints on transpiration with limited data, and to help decision making toward more sustainable rubber plantations.
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Affiliation(s)
- Jessada Sopharat
- Department of Plant Science, Faculty of Natural Resources, Prince of Songkla UniversitySongkhla, Thailand
| | - Frederic Gay
- UMR Eco&Sols, French Agricultural Research Centre for International Development (CIRAD)Montpellier, France
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
| | - Philippe Thaler
- UMR Eco&Sols, French Agricultural Research Centre for International Development (CIRAD)Montpellier, France
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
| | - Sayan Sdoodee
- Department of Plant Science, Faculty of Natural Resources, Prince of Songkla UniversitySongkhla, Thailand
| | | | - Charlchai Tanavud
- Department of Earth Science, Faculty of Natural Resources, Prince of Songkla UniversitySongkhla, Thailand
| | - Claude Hammecker
- UMR Eco&Sols, Institut de Recherche pour le DéveloppementMontpellier, France
| | - Frederic C. Do
- UMR Eco&Sols, Institut de Recherche pour le DéveloppementMontpellier, France
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11
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Wang LF. Physiological and molecular responses to drought stress in rubber tree (Hevea brasiliensis Muell. Arg.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 83:243-9. [PMID: 25194774 DOI: 10.1016/j.plaphy.2014.08.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 08/14/2014] [Indexed: 05/25/2023]
Abstract
Plant drought stress response and tolerance are complex biological processes. In order to reveal the drought tolerance mechanism in rubber tree, physiological responses and expressions of genes involved in energy biosynthesis and reactive oxygen species (ROS) scavenging were systematically analyzed following drought stress treatment. Results showed that relative water content (RWC) in leaves was continuously decreased with the severity of drought stress. Wilting leaves were observed at 7 day without water (dww). Total chlorophyll content was increased at 1 dww, but decreased from 3 dww. However, the contents of malondialdehyde (MDA) and proline were significantly increased under drought stress. Peroxidase (POD) and superoxide dismutase (SOD) activities were markedly enhanced at 1 and 3 dww, respectively. Meanwhile, the soluble sugar content was constant under drought stress. These indicated that photosynthetic activity and membrane lipid integrity were quickly attenuated by drought stress in rubber tree, and osmoregulation participated in drought tolerance mechanism in rubber tree. Expressions of energy biosynthesis and ROS scavenging systems related genes, including HbCuZnSOD, HbMnSOD, HbAPX, HbCAT, HbCOA, HbATP, and HbACAT demonstrated that these genes were significantly up-regulated by drought stress, and reached a maximum at 3 dww, then followed by a decrease from 5 dww. These results suggested that drought stress adaption in rubber tree was governed by energy biosynthesis, antioxidative enzymes, and osmoregulation.
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Affiliation(s)
- Li-feng Wang
- Danzhou Investigation & Experiment Station of Tropical Crops, Ministry of Agriculture, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, China.
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12
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Kobayashi N, Kumagai T, Miyazawa Y, Matsumoto K, Tateishi M, Lim TK, Mudd RG, Ziegler AD, Giambelluca TW, Yin S. Transpiration characteristics of a rubber plantation in central Cambodia. TREE PHYSIOLOGY 2014; 34:285-301. [PMID: 24646689 DOI: 10.1093/treephys/tpu009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The rapid and widespread expansion of rubber plantations in Southeast Asia necessitates a greater understanding of tree physiology and the impacts of water consumption on local hydrology. Sap flow measurements were used to study the intra- and inter-annual variations in transpiration rate (Et) in a rubber stand in the low-elevation plain of central Cambodia. Mean stand sap flux density (JS) indicates that rubber trees actively transpire in the rainy season, but become inactive in the dry season. A sharp, brief drop in JS occurred simultaneously with leaf shedding in the middle of the dry season in January. Although the annual maxima of JS were approximately the same in the two study years, the maximum daily stand Et of ∼2.0 mm day(-1) in 2010 increased to ∼2.4 mm day(-1) in 2011. Canopy-level stomatal response was well explained by changes in solar radiation, vapor pressure deficit, soil moisture availability, leaf area, and stem diameter. Rubber trees had a relatively small potential to transpire at the beginning of the study period, compared with average diffuse-porous species. After 2 years of growth in stem diameter, transpiration potential was comparable to other species. The sensitivity of canopy conductance (gc) to atmospheric drought indicates isohydric behavior of rubber trees. Modeling also predicted a relatively small sensitivity of gc to the soil moisture deficit and a rapid decrease in gc under extreme drought conditions. However, annual observations suggest the possibility of a change in leaf characteristics with tree maturity and/or initiation of latex tapping. The estimated annual stand Et was 469 mm year(-1) in 2010, increasing to 658 mm year(-1) in 2011. Diagnostic analysis using the derived gc model showed that inter-annual change in stand Et in the rapidly growing young rubber stand was determined mainly by tree growth rate, not by differences in air and soil variables in the surrounding environment. Future research should focus on the potentially broad applicability of the relationship between Et and tree size as well as environmental factors at stands different in terms of clonal type and age.
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Affiliation(s)
- Nakako Kobayashi
- Hydrospheric Atmospheric Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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13
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Chairungsee N, Gay F, Thaler P, Kasemsap P, Thanisawanyangkura S, Chantuma A, Jourdan C. Impact of tapping and soil water status on fine root dynamics in a rubber tree plantation in Thailand. FRONTIERS IN PLANT SCIENCE 2013; 4:538. [PMID: 24400016 PMCID: PMC3872315 DOI: 10.3389/fpls.2013.00538] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/11/2013] [Indexed: 05/13/2023]
Abstract
Fine roots (FR) play a major role in the water and nutrient uptake of plants and contribute significantly to the carbon and nutrient cycles of ecosystems through their annual production and turnover. FR growth dynamics were studied to understand the endogenous and exogenous factors driving these processes in a 14-year-old plantation of rubber trees located in eastern Thailand. FR dynamics were observed using field rhizotrons from October 2007 to October 2009. This period covered two complete dry seasons (November to March) and two complete rainy seasons (April to October), allowing us to study the effect of rainfall seasonality on FR dynamics. Rainfall and its distribution during the two successive years showed strong differences with 1500 and 950 mm in 2008 and 2009, respectively. FR production (FRP) completely stopped during the dry seasons and resumed quickly after the first rains. During the rainy seasons, FRP and the daily root elongation rate (RER) were highly variable and exhibited strong annual variations with a total FRP of 139.8 and 40.4 mm(-) (2) and an average RER of 0.16 and 0.12 cm day(-) (1) in 2008 and 2009, respectively. The significant positive correlations found between FRP, RER, the appearance of new roots, and rainfall at monthly intervals revealed the impact of rainfall seasonality on FR dynamics. However, the rainfall patterns failed to explain the weekly variations of FR dynamics observed particularly during the rainy seasons. At this time step, FRP, RER, and the appearance of new FR were negatively correlated to the average soil matric potential measured at a depth of between 30 and 60 cm. In addition, our study revealed a significant negative correlation between FR dynamics and the monthly production of dry rubber. Consequently, latex harvesting might disturb carbon dynamics in the whole tree, far beyond the trunk where the tapping was performed. These results exhibit the impact of climatic conditions and tapping system in the carbon budget of rubber plantations.
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Affiliation(s)
| | - Frederic Gay
- CIRAD, UMR Eco&SolsMontpellier, France
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
| | - Philippe Thaler
- CIRAD, UMR Eco&SolsMontpellier, France
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
| | - Poonpipope Kasemsap
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
- Faculty of Agriculture, Kasetsart UniversityBangkok, Thailand
| | - Sornprach Thanisawanyangkura
- Hevea Research Platform in Partnership, DORAS Centre, Kasetsart UniversityBangkok, Thailand
- Faculty of Science, Kasetsart UniversityBangkok, Thailand
| | - Arak Chantuma
- Chachoengsao Rubber Research Center, Department of AgricultureChachoengsao, Thailand
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Kumagai T, Mudd RG, Miyazawa Y, Liu W, Giambelluca TW, Kobayashi N, Lim TK, Jomura M, Matsumoto K, Huang M, Chen Q, Ziegler A, Yin S. Simulation of canopy CO2/H2O fluxes for a rubber (Hevea brasiliensis) plantation in central Cambodia: The effect of the regular spacing of planted trees. Ecol Modell 2013. [DOI: 10.1016/j.ecolmodel.2013.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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