Your search found 23 records
1 Doran, J.C.; Turnbull, J.W. (Eds.) 1997. Australian trees and shrubs: Species for land rehabilitation and farm planting in the tropics. Canberra, Australia: ACIAR. viii, 384p.: col.; ill., maps (chiefly col.) ; 26 cm.
(Location: IWMI-SEA Call no: 634.90913 G850 DOR Record No: BKK-119)
2 Chbouki, N.; Stockton, C. W.; Myers, D. 1995. Spatio-temporal patterns of drought in Morocco. International Journal of Climatology, 15:187-205.
(Location: IWMI-HQ Call no: P 7571 Record No: H039100)
3 Zomer, Robert J.; Bossio, Deborah A.; Trabucco, Antonio; Yuanjie, Li; Gupta, Diwan C.; Singh, Virendra P. 2007. Trees and water: smallholder agroforestry on irrigated lands in Northern India. Colombo, Sri Lanka: International Water Management Institute (IWMI). 41p. (IWMI Research Report 122) [doi: https://doi.org/10.3910/2009.122]
Trees ; Populus deltoids ; Agroforestry ; Afforestation ; Reforestation ; Models ; Water use ; Water balance ; Evapotranspiration ; Precipitation ; Remote sensing ; Irrigation requirements / India
(Location: IWMI HQ Call no: IWMI 631.7.2 G635 ZOM Record No: H041069)
(1.07 MB)
Trees are increasingly grown on-farm to supply wood and biomass needs within developing countries. Over the last several decades, within the irrigated rice-wheat growing lands of northern India, fast-growing poplar trees have been planted on tens of thousands of small farms. Recent debate regarding afforestation has raised the issue that water use is often increased when trees are planted. This ongoing debate focuses primarily on afforestation or reforestation of upland and rain-fed agricultural areas, and off-site impacts such as reduced streamflow. Adoption of poplar agroforestry in northern India, in contrast, is occurring in areas where land and water are already intensively used and managed for agricultural production. This study based on farmer survey data, used remote sensing and spatial hydrological modeling to investigate the importance and role of the poplar trees within the agricultural landscape, and to estimate their water use. Overall, results illustrate a potential for addressing the increasing global demand for wood products with trees grown on-farm within irrigated agroforestry systems.
4 Melvani, K.; Chandrasekera, K.; Mudannayake, R. 2006. The role of trees in the bioremediation of drinking water: a research experiment in Nawakkaduwa, Kalpitiya. In Water, Engineering and Development Centre (WEDC). Sustainable development of water resources, water supply and environmental sanitation: 32nd WEDC International Conference, Bandaranaike Memorial International Conference Hall, Colombo, Sri Lanka, 13th - 17th November 2006. Preprints. Leicestershire, UK: Water, Engineering and Development Centre (WEDC) pp.608-616.
Trees ; Bioremediation ; Pollution control ; Drinking water ; Water quality ; Public health / Sri Lanka / Kalpitiya / Nawakkaduwa
(Location: IWMI HQ Call no: 333.91 G000 WAT Record No: H041053)
5 Trabucco, Antonio; Zomer, R. J.; Bossio, Deborah A.; van Straaten, Oliver; Verchot, L. V. 2008. Climate change mitigation through afforestation/reforestation: a global analysis of hydrologic impacts with four case studies. Agriculture, Ecosystems and Environment, 126: 81-97.
Climate change ; Afforestation ; Reforestation ; Hydrology ; Water balance ; Models ; Evapotranspiration ; Trees ; Forests
(Location: IWMI HQ Call no: IWMI 333.75152 G000 TRA Record No: H041200)
The implicit hydrologic dimensions of international efforts to mitigate climate change, specifically potential impacts of the Clean Development Mechanism- Afforestation/Reforestation (CDM-AR) provisions of the Kyoto Protocol (KP) on global, regional and local water cycles, are examined. The global impact of the redistribution of water use driven by agriculture and land use change, of which CDM-AR can be a contributing factor, is a major component of ongoing global change and climate change processes. If converted to forest, large areas deemed suitable for CDM-AR would exhibit increases in actual evapotranspiration (AET) and/or decreases in runoff. Almost 20% (144 Mha) of all suitable land showed little or no impact on runoff and another 28% (210 Mha) showed only moderate impact. About 27% (200 Mha) was in the highest impact class, exhibiting an 80–100% decrease in runoff, and prevalent in drier areas (based on Aridity Index (AI)), the semi-arid tropics, and in conversion from grasslands and subsistence agriculture. Significant impacts on local hydrologic cycles were evident, however large impacts were not predicted at regional or global scale due primarily to the current limit on carbon offset projects under the Kyoto Protocol. Predicted decreases in runoff ranged from 54% in drier areas to less than 15% in more humid areas, based on four case studies located across a range of biophysical conditions and project scenarios in Ecuador and Bolivia. Factors other than climate, e.g. upstream/downstream position, were shown to be important in evaluating off-site impacts. This study demonstrates that it will become increasingly important to consider implications on local to regional water resources, and how the hydrologic dimension of CDM-AR impacts on issues of sustainability, local communities, and food security.
6 Zomer, R. J.; Trabucco, Antonio; Bossio, Deborah A.; Verchot, L. V. 2008. Climate change mitigation: a spatial analysis of global land suitability for clean development mechanism afforestation and reforestation. Agriculture, Ecosystems and Environment, 126: 67-80.
Climate change ; Land degradation ; Afforestation ; Reforestation ; Land use ; Models ; Trees ; Forests ; Carbon
(Location: IWMI HQ Call no: IWMI 333.75152 G000 ZOM Record No: H041201)
Within the Kyoto Protocol, the clean development mechanism (CDM) is an instrument intended to reduce greenhouse gas emissions, while assisting developing countries in achieving sustainable development, with the multiple goals of poverty reduction, environmental benefits and cost-effective emission reductions. The CDM allows for a small percentage of emission reduction credits to come from afforestation and reforestation (CDM-AR) projects. We conducted a global analysis of land suitability for CDM-AR carbon ‘sink’ projects and identified large amounts of land (749 Mha) as biophysically suitable and meeting the CDM-AR eligibility criteria. Forty-six percent of all the suitable areas globally were found in South America and 27% in Sub-Saharan Africa. In Asia, despite the larger land mass, relatively less land was available. In South America and Sub-Saharan Africa the majority of the suitable land was shrubland/grassland or savanna. In Asia the majority of the land was low-intensity agriculture. The sociologic and ecological analyses showed that large amounts of suitable land exhibited relatively low population densities. Many of the most marginal areas were eliminated due to high aridity, which resulted in a generally Gaussian distribution of land productivity classes. If the cap on CDM-AR were raised to compensate for a substantially greater offset of carbon emission through sink projects, this study suggests that it will be increasingly important to consider implications on local to regional food security and local community livelihoods.
7 Worbes, M.; Botman, E.; Khamzina, A.; Tupitsa, A.; Martius, C.; Lamers, J. P. A. 2006. Scope and constraints for tree planting in the irrigated landscapes of the Aral Sea Basin: case studies in Khorezm Region, Uzbekistan. Bonn, Germany: Center for Development Research. 49p. (ZEF Discussion Papers on Development Policy 112)
Lakes ; Agroforestry ; Trees ; Windbreak trees ; Forests ; Legal aspects ; Irrigated land ; Farmers attitudes ; Legal aspects / Central Asia / Uzbekistan / Aral Sea Basin / Khorezm
(Location: IWMI HQ Call no: e-copy only Record No: H041351)
http://www.zef.de/fileadmin/webfiles/downloads/zef_dp/zefdp_112.pdf
https://vlibrary.iwmi.org/pdf/H041351.pdf
https://vlibrary.iwmi.org/pdf/H041351.pdf
8 Qadir, Manzoor; Noble, Andrew; Qureshi, Asad Sarwar; Gupta, R. K.; Yuldashev, T.; Karimov, Akmal. 2009. Salt-induced land and water degradation in the Aral Sea basin: a challenge to sustainable agriculture in Central Asia. Natural Resources Forum, 33:134-149.
Water resources ; River basins ; Groundwater ; Soil salinity ; Soil degradation ; Soil improvement ; Soil reclamation ; Fertilizer application ; Waterlogging ; Water quality ; Saline water ; Irrigation water ; Subsurface drainage ; Trees ; Evapotranspiration ; Pumps ; Land degradation ; Farming systems ; Rice / Central Asia / Kyrgyzstan / Tajikistan / Kazakhstan / Turkmenistan / Uzbekistan / Aral Sea / Amu-Darya Basin / Syr-Darya Basin
(Location: IWMI HQ Call no: e-copy only Record No: H042212)
(0.49 MB)
Expansion of irrigated agriculture in the Aral Sea Basin in the second half of the twentieth century led to the conversion of vast tracks of virgin land into productive agricultural systems resulting in significant increases in employment opportunities and income generation. The positive effects of the development of irrigated agriculture were replete with serious environmental implications. Excessive use of irrigation water coupled with inadequate drainage systems has caused largescale land degradation and water quality deterioration in downstream parts of the basin, which is fed by two main rivers, the Amu-Darya and Syr-Darya. Recent estimates suggest that more than 50% of irrigated soils are salt-affected and/or waterlogged in Central Asia. Considering the availability of natural and human resources in the Aral Sea Basin as well as the recent research addressing soil and water management, there is cause for cautious optimism. Research-based interventions that have shown significant promise in addressing this impasse include: (1) rehabilitation of abandoned salt-affected lands through halophytic plant species; (2) introduction of 35-day-old early maturing rice varieties to withstand ambient soil and irrigation water salinity; (3) productivity enhancement of high-magnesium soils and water resources through calcium-based soil amendments; (4) use of certain tree species as biological pumps to lower elevated groundwater levels in waterlogged areas; (5) optimal use of fertilizers, particularly those supplying nitrogen, to mitigate the adverse effects of soil and irrigation water salinity; (6) mulching of furrows under saline conditions to reduce evaporation and salinity buildup in the root zone; and (7) establishment of multipurpose tree and shrub species for biomass and renewable energy production. Because of water withdrawals for agriculture from two main transboundary rivers in the Aral Sea Basin, there would be a need for policy level interventions conducive for enhancing interstate cooperation to transform salt-affected soil and saline water resources from an environmental and productivity constraint into an economic asset.
9 Lemenih, Mulugeta. 2011. Role of forests and trees outside forests in livelihoods and climate change adaptation. In Kelbesa, E.; Girmna, A. (Eds.). Multiple uses of forests in Ethiopia vs associated challenge - maximizing benefits while curbing limitations: commemoration of 3rd National Mother Earth Day and 2011 International Year of Forests - Forum for Environment, Addis Ababa, Ethiopia, 29 April 2011. Addis Ababa, Ethiopia: Climate Change Forum. pp.95-110.
Forests ; Trees ; Climate change ; Adaptation ; Poverty ; Households ; Economic aspects ; Income ; Food security ; Vegetation ; Case studies ; Arid zones / Ethiopia / Tigray / Dendi Woreda / Adaba-Dodolla / Menagesha Suba / West Hararghe / Somali Region
(Location: IWMI HQ Call no: e-copy only Record No: H044572)
(0.53 MB)
10 Mekuria, Wolde; Sengtaheuanghoung, O.; Hoanh, Chu Thai; Noble, A. 2012. Economic contribution and the potential use of wood charcoal for soil restoration: a case study of village-based charcoal production in Central Laos. International Journal of Sustainable Development and World Ecology, 19(5):415-425. [doi: https://doi.org/10.1080/13504509.2012.686070]
Wood ; Trees ; Charcoal ; Fuelwood ; Case studies ; Production possibilities ; Chemicophysical properties ; Economic aspects ; Profitability ; Biomass ; Energy consumption ; Soil improvement ; Water availability ; Forestry ; Developing countries ; Rural areas ; Income / Laos
(Location: IWMI HQ Call no: e-copy only Record No: H044884)
(0.65 MB)
Wood charcoal production provides affordable energy in many developing countries and has substantially contributed to the economy through the provision of rural incomes. In several countries, charcoal production leads to overexploitation of forests due to inefficiencies in processing. This study was undertaken in central Laos to (1) examine and document traditional charcoal production systems; (2) investigate the production capacity, recovery efficiencies and economic gains of existing traditional charcoal production methods; (3) characterize the chemical properties of wood charcoal and investigate the potential for soil restoration and (4) investigate local charcoal producers’ perception on forest degradation and their species preferences. Through a socio-economic survey, a cost-based method for economic valuation was undertaken on a range of charcoal production methods currently being used. Laboratory chemical analyses were performed on wood charcoal samples. Results indicated that the traditional mud charcoal mound was used by the majority (82%) of charcoal producers. Total charcoal production per production cycle varied between 400 (produced from 2.7 m3 of wood) and 1600 kg (produced from 18 m3 of wood), with a mean of 938 kg (±120) for traditional mud charcoal mounds. The volume of the traditional mud charcoal mounds correlated positively and significantly with total charcoal production (R2 = 0.45, p = 0.03), whereas correlated negatively and significantly with the recovery efficiency (R2 = 0.58, p = 0.01). On average, the local producers receive a total net benefit of 457,272 Lao kip (USD 57.2) in 17 days. We also identified a rice husk mound method of charcoal production, which may not encourage further deforestation while producing rice husk biochar that can be used for soil restoration. Furthermore, we found that there are significant differences (p < 0.05) between the sampled wood charcoals in chemical properties, indicating that the potential of using wood charcoal for the restoration of degraded soils varies from charcoal to charcoal.
11 Peesapaty, N; Sharma, Bharat; Samad, Madar. 2005. Effectiveness of Andhra Pradesh [India] water land and trees act 2002 on groundwater extraction. In Mathur, G. N.; Chawla, A. S. (Eds.). Water for sustainable development - towards innovative solutions: proceedings of the XII World Water Congress, New Delhi, India, 22-25 November 2005. Vol. 3. New Delhi, India: Central Board of Irrigation and Power; Montpellier, France: International Water Resources Association (IWRA). pp.3:11-3:22.
Water resources ; Land resources ; Trees ; Legislation ; Groundwater management ; Groundwater extraction ; Groundwater irrigation ; Agricultural development / India / Andhra Pradesh
(Location: IWMI HQ Call no: 333.91 G000 MAT Record No: H045960)
(0.90 MB)
12 Mekuria, Wolde; Hadgu, K. M.; Desta, L. T. 2014. The role of trees in regulating soil erosion. In de Leeuw, J.; Njenga, M.; Wagner, B.; Iiyama, M. (Eds.). Treesilience: an assessment of the resilience provided by trees in the drylands of Eastern Africa. Nairobi, Kenya: World Agroforestry Centre (ICRAF) pp.94-97.
Trees ; Soil erosion ; Soil conservation ; Soil fertility ; Soil water ; Land management ; Sediment ; Arid zones
(Location: IWMI HQ Call no: e-copy only Record No: H046287)
http://www.worldagroforestry.org/downloads/publications/PDFs/B17611.PDF
https://vlibrary.iwmi.org/pdf/H046287.pdf
https://vlibrary.iwmi.org/pdf/H046287.pdf
(0.33 MB) (4.69 MB)
13 Qadir, M.; Noble, Andrew D.; Karajeh, F.; George, B. 2015. Potential business opportunities from saline water and salt-affected land resources. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). 29p. (Resource Recovery and Reuse Series 05) [doi: https://doi.org/10.5337/2015.206]
Land resources ; Land degradation ; Saline water ; Sodic soils ; Soil salinity ; Desalination ; Crop production ; Ecosystems ; Aquaculture ; Water resources ; Water productivity ; Drainage water ; Water reuse ; Recycling ; Freshwater ; Soil properties ; Magnesium ; Phosphogypsum ; Energy generation ; Solar energy ; Horticulture ; Greenhouses ; Irrigation ; Deltas ; Trees ; Case studies / Egypt
(Location: IWMI HQ Call no: IWMI Record No: H046996)
(1 MB)
14 Nair, P. K. R.; Garrity, D. (Eds.) 2012. Agroforestry - the future of global land use. Dordrecht, Netherlands: Springer. 549p. (Advances in Agroforestry 9) [doi: https://doi.org/10.1007/978-94-007-4676-3]
Agroforestry systems ; Land use ; Land management ; Landscape ; Climate change ; Adaptation ; Habitats ; Ecosystem services ; Biodiversity conservation ; Rural development ; Trees ; Domestication ; Carbon sequestration ; Carbon credits ; Agriculture ; Farming systems ; Research and Development ; Energy conservation ; Energy generation ; Renewable energy ; Bioenergy ; Industrialization ; Soil properties ; Rangelands ; Gender ; Smallholders ; Food security ; Germplasm ; Rehabilitation ; Greenhouse gases ; Emission ; Sustainability ; Organic agriculture ; Organic fertilizers ; Faidherbia albida ; Natural resources management ; Forest conservation ; Tillage ; Residues ; Nutrient cycling ; Grazing ; Cropping systems ; Shifting cultivation ; Rubber plants ; Wetlands ; Living standards ; Cashews ; Smallholders ; Fruit growing ; Poverty ; Rural communities ; Environmental policy ; Environmental services ; Silvopastoral systems ; Economic aspects ; Alley cropping ; Reclamation ; Indigenous knowledge ; Urbanization ; Agrobiodiversity ; Fertilizers ; Resource conservation ; Legal aspects ; Corporate culture ; Theobroma cacao ; Coffea ; Forage ; Soil fertility ; Case studies / Asia / Europe / Africa / Indonesia / China / USA / Canada / Japan / Latin America / Kenya / Philippines / Niger / Amazon / Sumatra / Xishuangbanna
(Location: IWMI HQ Call no: e-copy SF Record No: H047924)
15 Amarnath, Giriraj; Babar, S.; Murthy, M. S. R. 2017. Evaluating MODIS-vegetation continuous field products to assess tree cover change and forest fragmentation in India: a multi-scale satellite remote sensing approach. The Egyptian Journal of Remote Sensing and Space Sciences, 20:157-168. [doi: https://doi.org/10.1016/j.ejrs.2017.05.004]
Remote sensing ; Models ; Vegetation ; Satellite imagery ; Forest fragmentation ; Forest ecosystems ; Trees ; Canopy ; Time series analysis ; Deforestation ; Landscape ; Climate change / India
(Location: IWMI HQ Call no: e-copy only Record No: H048220)
http://www.sciencedirect.com/science/article/pii/S1110982317302132/pdfft?md5=272802c5ea945f049718e7f6501c83bf&pid=1-s2.0-S1110982317302132-main.pdf
https://vlibrary.iwmi.org/pdf/H048220.pdf
https://vlibrary.iwmi.org/pdf/H048220.pdf
(3.34 MB)
Monitoring the changes in forest-cover and understanding the dynamics of the forest is becoming increasingly important for the sustainable management of forest ecosystems. This paper uses temporal MODIS Vegetation Continuous Field (MODIS-VCF) to monitor the tree cover change in the Indian region over a period of 6 years (2000–2005). Pixel-based linear regression model is developed to identify rate of deforestation and fragmentation at landscape level. The regression parameters viz., slope, offset and variance are used to identify threshold between forest and non-forest classes. The classification algorithm resulted into change area, no change area, positive change and negative changes. MODIS-VCF raw product of 2005 was validated using the field data and showed a coefficient of determination (R2 = 0.85) between percent tree cover and individual plot wise canopy cover information. The results were overlaid with UNEP protected area boundary. On a long-term basis, the forest cover change was monitored using medium spatial resolution (Landsat and IRS) satellite data to identify the rate of deforestation and fragmentation at landscape level. The developed approach is efficient and effective for regional monitoring of forest cover change. It could be automated for regular usage and monitoring.
16 Byg, A.; Novo, P.; Dinato, M.; Moges, A.; Tefera, T.; Balana, Bedru; Woldeamanuel, T.; Black, H. 2017. Trees, soils, and warthogs - distribution of services and disservices from reforestation areas in southern Ethiopia. Forest Policy and Economics, 84:112-119. (Special issue: Forest, Food, and Livelihoods). [doi: https://doi.org/10.1016/j.forpol.2017.06.002]
Ecosystem services ; Reforestation ; Projects ; Trees ; Soil fertility ; Erosion ; Nature conservation ; Environmental protection ; Strategies ; Local communities ; Attitudes ; Living standards ; Wild animals ; Warthogs / Ethiopia / Halaba / Laygnaw Arsho / Assore / Andegna Choroko
(Location: IWMI HQ Call no: e-copy only Record No: H048337)
http://www.sciencedirect.com/science/article/pii/S1389934117302952/pdfft?md5=d5a4e1fd1e420f6d856f06bafde2b015&pid=1-s2.0-S1389934117302952-main.pdf
https://vlibrary.iwmi.org/pdf/H048337.pdf
https://vlibrary.iwmi.org/pdf/H048337.pdf
(0.31 MB) (316 KB)
Conservation projects have often been criticised for creating global benefits while causing negative impacts on local livelihoods. Ecosystem services approaches have been seen as one way to change this by focussing explicitly on maintaining ecosystems for human well-being of stakeholders at various scales. However, ecosystem services approaches have often ignored trade-offs between groups of people and issues of power and do not automatically lead to better outcomes in terms of human well-being. Here we report on a study on the impacts of reforestation projects with an explicit focus on human well-being in three communities in southern Ethiopia. We investigated the distribution of services and disservices from reforestation using qualitative methods. Results showed that the services and disservices from reforestation were distributed unequally across space and wealth groups resulting in widespread dissatisfaction with existing reforestation projects despite the explicit focus on human benefits. To improve outcomes of reforestation it is necessary to acknowledge and manage disservices adaptively, include issues of power and make trade-offs transparent.
17 Miles, K.-L.; Suhardiman, Diana; Dwyer, M. B. 2018. State spaces of resistance: industrial tree plantations and the struggle for land in Laos. Antipode, 50(5): 1290-1310. [doi: https://doi.org/10.1111/anti.12391]
Trees ; Plantations ; Land grabbing ; Land use ; Land ownership ; Resource management ; Governance ; Investment ; Rural areas ; Political aspects ; Agriculture ; Case studies / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H048621)
Land grabbing has transformed rural environments across the global South, generating resistance or political reactions “from below”. In authoritarian countries like Laos, where resource investments are coercively developed and insulated from political dissent, resistance appears absent at first glance. Yet, it is occurring under the radar, largely outside transnational activist networks. In this article, we examine how resistance can protect access to rural lands in contexts where it is heavily repressed. Resistance here occurs with, rather than against the state by foregrounding the contradictions of land use and ownership within state spaces, such as competing goals of large-scale industrial plantations versus smallholder agriculture and national forest conservation. Such contradictions are engaged by using historical, place-based political connections to exploit the scalar frictions of a fragmented state and occupying plantation clearance sites to highlight contested lands in situ. Nonetheless, such strategies remain spatially and socially uneven amongst the Lao peasantry.
18 Karg, H.; Drechsel, Pay. (Eds.) 2018. Atlas of West African urban food systems: examples from Ghana and Burkina Faso. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). 83p. [doi: https://doi.org/10.5337/2018.224]
Urban areas ; Urban agriculture ; Urban development ; Farming systems ; Livestock production ; Forestry ; Food marketing ; Food consumption ; Food composition ; Food safety ; Food policies ; Food supply ; Household consumption ; Stakeholders ; Diets ; Land use ; Vegetation ; Trees ; Backyard farming ; Crop production ; Cultivation ; Wastewater irrigation ; Wastewater treatment ; Water resources ; Nutrition / West Africa / Ghana / Burkina Faso / Tamale / Ouagadougou
(Location: IWMI HQ Call no: e-copy only Record No: H048998)
(10.0 MB)
This Atlas summarizes recent advances in interdisciplinary approaches and research to address the different components of West African urban food systems, including urban and peri-urban agriculture. It thereby draws on the results of several major collaborative research projects and stakeholder consultations conducted in West Africa over the past two decades, and in particular on the UrbanFoodPlus project in Ghana and Burkina Faso (www.urbanfoodplus.org). The publication targets with its innovative design a broad range of stakeholders.
19 Tfwala, C. M.; van Rensburg, L. D.; Bello, Z. A.; Zietsman, P. C. 2019. Transpiration dynamics and water sources for selected indigenous trees under varying soil water content. Agricultural and Forest Meteorology, 275:296-304. [doi: https://doi.org/10.1016/j.agrformet.2019.05.030]
Trees ; Transpiration ; Groundwater ; Water availability ; Soil water content ; Water use ; Water depletion ; Evapotranspiration ; Rain ; Chemicophysical properties ; Arid zones / South Africa / Kolomela Mine
(Location: IWMI HQ Call no: e-copy only Record No: H049326)
(2.17 MB)
The major route through which water from the earth’s surface re-enters the hydrologic cycle in forested ecosystems is via tree transpiration (T). It is therefore important to have detailed understanding of the quantity and source of water transpired by different tree species. The aims of this study were to i) assess the trends of T for selected tree species (camel thorn, sweet thorn, shepherd’s tree and buffalo thorn) across a range of soil water content conditions and ii) partition the total T of the selected tree species growing in arid environments dominated by open cast mining activities into soil water and groundwater. Tree T was measured using the compensation heat pulse velocity (CHPV) method, while soil water content was monitored using DFM capacitance probes. The soil water content within the upper 50 cm soil profile ranged from 11 mm during the dry season to 20 mm during the wet season. The deeper soil layer (50–120 cm) was generally wetter compared to the top layer with water content was up to >30 mm during the wet season. The measured tree T ranged from 0.2 mm day-1 on buffalo thorn during the dry season to 1.9 mm day-1 on sheperd’s tree in summer. It was also revealed that T of large (diameter at breast height =46 cm) camel thorn trees is not responsive to seasonal variations of soil water availability and remained constant at approximately 1.2 mm day-1. Diurnal patterns of T did not effect changes on the soil water depletions within the top 120 cm soil profile, which indicated that the trees sourced water beyond this zone. Signs of daytime redistribution were observed within the canopy areas of the investigated trees during very limited soil water conditions of the dry season. It was concluded that the water use of trees is inclined to the seasonal variations, which however is not the case in old trees. Close to 100% of the water transpired by trees in the study area is sourced below 1.2 m (vadose zone and water table). We recommended investigation of daytime redistribution among the indigenous tree species of the study area. We also recommended extension of tree water use studies to other species for comprehensive catchment tree water use calculations to inform water budgets.
20 Bachiller-Jareno, N.; Hutchins, M. G.; Bowes, M. J.; Charlton, M. B.; Orr, H.G. 2019. A novel application of remote sensing for modelling impacts of tree shading on water quality. Journal of Environmental Management, 230:33-42. [doi: https://doi.org/10.1016/j.jenvman.2018.09.037]
Water quality ; Remote sensing ; Riparian vegetation ; Trees ; Canopy ; Rivers ; Surface water ; Water temperature ; Geographical information systems ; Models / England / River Thames
(Location: IWMI HQ Call no: e-copy only Record No: H049295)
(2.02 MB)
Uncertainty in capturing the effects of riparian tree shade for assessment of algal growth rates and water temperature hinders the predictive capability of models applied for river basin management. Using photogrammetry-derived tree canopy data, we quantified hourly shade along the River Thames (UK) and used it to estimate the reduction in the amount of direct radiation reaching the water surface. In addition we tested the suitability of freely-available LIDAR data to map ground elevation. Following removal of buildings and objects other than trees from the LIDAR dataset, results revealed considerable differences between photogrammetry- and LIDAR-derived methods in variables including mean canopy height (10.5 m and 4.0 m respectively), percentage occupancy of riparian zones by trees (45% and 16% respectively) and mid-summer fractional penetration of direct radiation (65% and 76% respectively). The generated data on daily direct radiation for 2010 were used as input to a river network water quality model (QUESTOR). Impacts of tree shading were assessed in terms of upper quartile levels, revealing substantial differences in indicators such as biochemical oxygen demand (BOD) (1.58–2.19 mg L-1 respectively) and water temperature (20.1 and 21.2 °C respectively) between ‘shaded’ and ‘non-shaded’ radiation inputs. Whilst the differences in canopy height and extent derived by the two methods are appreciable they only make small differences to water quality in the Thames. However such differences may prove more critical in smaller rivers. We highlight the importance of accurate estimation of shading in water quality modelling and recommend use of high resolution remotely sensed spatial data to characterise riparian canopies. Our paper illustrates how it is now possible to make better reach scale estimates of shade and make aggregations of these for use at river basin scale. This will allow provision of more effective guidance for riparian management programmes than currently possible. This is important to support adaptation to future warming and maintenance of water quality standards
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