Dynamics of evapotranspiration partitioning for apple trees of different ages in a semiarid region of northwest China

Evapotranspiration in semiarid regions generally represents the greatest loss of water from an ecosystem and is sensitive to changes in the cover of vegetation. In this work, we compared the effects of apple tree of different ages by partitioning evapotranspiration into canopy interception (calculated), tree transpiration (thermal-dissipation probes) and soil evaporation (micro-lysimeter) in a semiarid region of northwest China from May to September in 2012, 2013 and 2014. Tree age had a clear influence on evapotranspiration partitioning. Daily transpiration and evapotranspiration were always higher for the 17- than the 7-year-old trees. Monthly canopy interception and transpiration of the 17-year-old trees were always higher, and monthly soil evaporation was always lower than the 7-year-old trees. Evapotranspiration was 339.1, 341.4 and 312.4 mm and 361.1, 367.2 and 336.3 mm for the 7- and 17-year-old trees in 2012, 2013 and 2014, respectively. Annual soil evaporation accounted for a large proportion of the evapotranspiration for the 7-year-old apple trees, ranging from 51.7 to 53.6%, and transpiration accounted for a large proportion of the evapotranspiration for the 17-year-old apple trees, ranging from 47.8 to 49.1%. Reference evapotranspiration was low during our experimental periods, and the relationship between actual evapotranspiration and reference evapotranspiration differed between the 7- and 17-year-old trees. Tree age was mostly responsible for the differences in evapotranspiration and its partitioning due to the morphologies of the trees. Tree age should therefore be taken into account when assessing the influence of evapotranspiration by apple trees on regional water budgets under our or similar climatic conditions. (C) 2017 Elsevier B.V. All rights reserved

Ecological Footprint Analysis Applied to a Coal-Consumption County in China

Sustainable development is a critical issue in developing countries, especially for some regions whose economy depends greatly on non-renewable resources. The ecological footprint is a measured area-based indicator to analyze the sustainable use of natural resources. It has been widely used to evaluate whether the natural ecosystem's carrying capacity in a region could support its development. In this study, the method was utilized to determine the per capita ecological footprint, biocapacity and related indices for Shenmu County. Results showed that the ecological deficit was 20.075 ha/capita (cap) in 2009, indicating that Shenmu County was practicing unsustainable development, both socially and economically, and was over-exploiting its natural resources and the environment. The ecological deficit worsened between 2004, when it was "overloading" (1.978 ha/cap), and 2009, when it was "seriously overloading" (20.075 ha/cap); this was linked to increases in the ecological footprint. The main reason for the ecological deficits was the large energy consumption of industrial production. Most coal consumption was used to produce coke, and coke output thus had that greatest impact on deficits as indicated by stepwise multiple linear regression. In order to decrease ecological deficits, attention should focus on the development of alternative energy sources or technology. Improving and changing land use and energy-consumption patterns to create a resource-saving approach would result in steady increases in resource conservation leading to sustainable consumption that will improve the future ecological environment of Shenmu County.Sustainable development is a critical issue in developing countries, especially for some regions whose economy depends greatly on non-renewable resources. The ecological footprint is a measured area-based indicator to analyze the sustainable use of natural resources. It has been widely used to evaluate whether the natural ecosystem's carrying capacity in a region could support its development. In this study, the method was utilized to determine the per capita ecological footprint, biocapacity and related indices for Shenmu County. Results showed that the ecological deficit was 20.075 ha/capita (cap) in 2009, indicating that Shenmu County was practicing unsustainable development, both socially and economically, and was over-exploiting its natural resources and the environment. The ecological deficit worsened between 2004, when it was "overloading" (1.978 ha/cap), and 2009, when it was "seriously overloading" (20.075 ha/cap); this was linked to increases in the ecological footprint. The main reason for the ecological deficits was the large energy consumption of industrial production. Most coal consumption was used to produce coke, and coke output thus had that greatest impact on deficits as indicated by stepwise multiple linear regression. In order to decrease ecological deficits, attention should focus on the development of alternative energy sources or technology. Improving and changing land use and energy-consumption patterns to create a resource-saving approach would result in steady increases in resource conservation leading to sustainable consumption that will improve the future ecological environment of Shenmu County