Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink fo...Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and re-lated natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases con-centrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire. In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmos-pheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH4 oxidation in various forest soils of different areas.展开更多
Tree species respond to climate change at multiple scales,such as species physiological response at fine scale and species distribution (quantified by percent area) at broader spatial scale.At a given spatial scale,sp...Tree species respond to climate change at multiple scales,such as species physiological response at fine scale and species distribution (quantified by percent area) at broader spatial scale.At a given spatial scale,species physiological response and distribution can be correlated positively or negatively.The consistency of such correlation relationships at different spatial scales determines whether species responses derived from local scales can be extrapo-lated to broader spatial scales.In this study,we used a coupled modeling approach that coupled a plot-level ecosystem process model (LINKAGES) with a spatially explicit landscape model (LANDIS).We investigated species physio-logical responses and distribution responses to climate warming at the local,zonal and landscape scales respectively,and examined how species physiological response and distribution correlated at each corresponding scale and whether the correlations were consistent among these scales.The results indicate that for zonal and warming-sensitive species,the correlations between species physiological response and distribution are consistent at these spatial scales,and therefore the research results of vegetation response to climate warming at the local scale can be extrapolated to the zonal and landscape scales.By contrast,for zonal and warming-insensitive species the correlations among different spatial scales are consistent at some spatial scales but at other scales.The results also suggest that the results of azonal species at the local scale near their distribution boundaries can not be extrapolated simply to broader scales due to stronger responses to climate warming in those boundary regions.展开更多
Since 1790, Antarctic living resources were becoming subjects of competition among the exploiters to be first in obtaining the maximum profit from them. This led to subsequent extinction of valuable species from fur s...Since 1790, Antarctic living resources were becoming subjects of competition among the exploiters to be first in obtaining the maximum profit from them. This led to subsequent extinction of valuable species from fur seals and next penguins, large through small whales, industrial demersal fish, further to pelagic species and now toothfish, crabs and krill. Catch proportions of their numerous and biomass decrease. The biomass of South Georgia Icefish estimated for 40 years in spide of decreasing trend has one of the largest components-the oscillations with periods of 3 years or 4 years. Their models explain large biomass fluctuations in the years 1975 to 1981 with amplitudes ±15 × 10^3 tonnes around average 20 ×10^3 tonnes and further decline up to 2005 season with oscillation ±4 ×10^3 tonnes around average 5 × 10^3 tonnes. For future season, 2016 model predicts a little increase of the biomass oscillation at level of 8 × 10^3 tonnes with reduced amplitude 2 × 10^3 tonnes. Slowly increase density of adult fish was also reported for target similar and close related mackerel icefish. Additional references for biomass levels help reduce the risk of further depletion biomass of Pseudochaenichthys georgianus which already declined to 75%. As global warming promote phytoplankton growth, replacing krill fishery by algae farms can save unique Antarctic heritages.展开更多
Phenological background information for alpine species is limited from extremely high altitudes. Flowering and fruiting phenology was monitored for 24 plant species at 5,180 m a.s.1, near the base camp area on the nor...Phenological background information for alpine species is limited from extremely high altitudes. Flowering and fruiting phenology was monitored for 24 plant species at 5,180 m a.s.1, near the base camp area on the north slope of Mt. Qomolangma （Mt. Everest） in Tibet, western China. The dates of first flowering, peak flowering, end of flowering, first fruiting, peak fruiting and flowering period were recorded. There was a wide variation in onset of flowering, long flowering duration, a relative synchrony between the onset of flowering and fruiting, and one species was exclusively vegetative. These results suggest that the species have evolved various phenological strategies as adaptations to the short growing season with limited resources and pollinators in this harsh alpine environment at extremely high elevations. With a background of global warming, local plant species will represent an advancing trend in onset of flowering.展开更多
The majority of livestock in the rural areas of Africa are indigenous types that are not well defined as breeds as perceived by the developed world. The animals in this important sector have remained largely uncharact...The majority of livestock in the rural areas of Africa are indigenous types that are not well defined as breeds as perceived by the developed world. The animals in this important sector have remained largely uncharacterised and face the risk of genetic dilution due to indiscriminate crossbreeding, breed replacement and neglect. This article uses two examples to describe a system that has been implemented in South Africa that allows indigenous livestock from rural keepers to enter the seed stock industry as recognized breeds. The first example is the indigenous Nguni breed of cattle that has been successfully developed into a seed stock breed, with a society celebrating its 25th anniversary in November 2011. The second example involves the challenges of developing a seed stock industry for some of the unimproved indigenous goat breeds of South Africa. Climate change is expected to have a more extreme effect on southern hemisphere continents than on other continents. Such negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. With the likelihood of global warming, these adapted genotypes can play a very important role in sustainable livestock production.展开更多
The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature （Tmin） has risen more than twice as fast as the daily maximum temperature （Tmax） during the 20th c...The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature （Tmin） has risen more than twice as fast as the daily maximum temperature （Tmax） during the 20th century. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to in- vestigate how the crops respond to the Train rise. In particular, no experiment research has reported on how crops respond to the higher night temperature, which was the main trend in the climate warming. Taking winter wheat as the test crop, we investi- gated how the winter wheat growth and yields responded to the higher night temperature. In the field experiments, infrared heaters were used to increase higher night temperature （HNT） by about 2.5℃ in contrast to the normal night temperature （CK） in two whole growth durations of winter wheat in 2008-2009 and 2009-2010 in North China. The results indicated that, com- pared to the CK treatment, winter wheat yield did not decline in HNT treatment, which increased temperatures by 2.0-2.5℃ in both Wanner year （WY） and Colder year （CY）. Furthermore, winter wheat yield in CY increased significantly in HNT treatment. HNT treatment in CY could significantly promote tillering and increase the effective panicles, which increased grain yield significantly （by more than 30% compared with CK）. HNT treatment in CY contributed to an increase in the effective panicles and Kernels significantly, although making a significant reduction in 1000-grain weight, but did not lead to the yield decline. Under the HNT treatment, the whole growth duration of the winter wheat was shortened and the phenological dates were earlier except for the beginning of overwintering; the beginnings of the overwintering phase were postponed substantially and the ends of the overwintering phase were ahead of date compared to CK, which shortened the duration of overwintering considerably. We draw on our own studies to show examples of higher night temperature impact on winter wheat in a relative- ly cold year and relatively warm year in North China. Our results refer to winter wheat in North China, not all main winter wheat producing regions, in Huang-Huai and Southwest of China. Some uncertainties of our predictions derive from fast pro- gress in crop breeding, the variability of climate, and the role of adaptive actions in the future. As expected, the adaptation measures should be considered to cope with the impacts of global warming on crops, and further research and assessments should be conducted.展开更多
Warming increases competition among plant species in alpine communities by ameliorating harsh environmental conditions,such as low temperatures. Grazing, as the main human activity, may mitigate the effect of warming,...Warming increases competition among plant species in alpine communities by ameliorating harsh environmental conditions,such as low temperatures. Grazing, as the main human activity, may mitigate the effect of warming, as previously reported.However, it is critical to refine the effects of warming on biotic interactions among species, for example, by taking the competitive ability of species into consideration. Based on a 10-year warming and grazing experiment in a Tibetan alpine meadow, we evaluated interspecific biotic interactions of dominant and subordinate species, using the approach of interspecific spatial associations. Warming significantly increased competition between subordinate and dominant species as well as among subordinate species, but not among dominant species. Moreover, facilitation of dominant-subordinate species also increased under warming. Simulated rotational grazing had similar effects to warming, with increasing interspecific competition. Our results show that, when studying the effects of warming on biotic interactions among species, it is necessary to characterize different species pairs relative to their competitive ability, and that simulated rotational grazing does not mitigate the effects of warming in the long term. Our results also provide evidence that the spatial pattern of species is a critical mechanism in species coexistence.展开更多
基金National Natural Science Foundation of China (No. 40171092).
文摘Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and re-lated natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases con-centrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire. In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmos-pheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH4 oxidation in various forest soils of different areas.
基金Under the auspices of International Partnership Program of Chinese Academy of Sciences (No.KZCX2-YW-T06)Key Direction in Knowledge Innovation Programs of Chinese Academy of Sciences (No.KZCX2-YW-444)Major State Basic Research Development Program of China (No.2009CB421101)
文摘Tree species respond to climate change at multiple scales,such as species physiological response at fine scale and species distribution (quantified by percent area) at broader spatial scale.At a given spatial scale,species physiological response and distribution can be correlated positively or negatively.The consistency of such correlation relationships at different spatial scales determines whether species responses derived from local scales can be extrapo-lated to broader spatial scales.In this study,we used a coupled modeling approach that coupled a plot-level ecosystem process model (LINKAGES) with a spatially explicit landscape model (LANDIS).We investigated species physio-logical responses and distribution responses to climate warming at the local,zonal and landscape scales respectively,and examined how species physiological response and distribution correlated at each corresponding scale and whether the correlations were consistent among these scales.The results indicate that for zonal and warming-sensitive species,the correlations between species physiological response and distribution are consistent at these spatial scales,and therefore the research results of vegetation response to climate warming at the local scale can be extrapolated to the zonal and landscape scales.By contrast,for zonal and warming-insensitive species the correlations among different spatial scales are consistent at some spatial scales but at other scales.The results also suggest that the results of azonal species at the local scale near their distribution boundaries can not be extrapolated simply to broader scales due to stronger responses to climate warming in those boundary regions.
文摘Since 1790, Antarctic living resources were becoming subjects of competition among the exploiters to be first in obtaining the maximum profit from them. This led to subsequent extinction of valuable species from fur seals and next penguins, large through small whales, industrial demersal fish, further to pelagic species and now toothfish, crabs and krill. Catch proportions of their numerous and biomass decrease. The biomass of South Georgia Icefish estimated for 40 years in spide of decreasing trend has one of the largest components-the oscillations with periods of 3 years or 4 years. Their models explain large biomass fluctuations in the years 1975 to 1981 with amplitudes ±15 × 10^3 tonnes around average 20 ×10^3 tonnes and further decline up to 2005 season with oscillation ±4 ×10^3 tonnes around average 5 × 10^3 tonnes. For future season, 2016 model predicts a little increase of the biomass oscillation at level of 8 × 10^3 tonnes with reduced amplitude 2 × 10^3 tonnes. Slowly increase density of adult fish was also reported for target similar and close related mackerel icefish. Additional references for biomass levels help reduce the risk of further depletion biomass of Pseudochaenichthys georgianus which already declined to 75%. As global warming promote phytoplankton growth, replacing krill fishery by algae farms can save unique Antarctic heritages.
基金supported jointly by 111 Project (Grant No. B08037)Project 6 of the National Basic Research Program of China (Grant No. 2005CB422006)a Natural Sciences and Engineering Research Council (Canada) discovery grant to RT
文摘Phenological background information for alpine species is limited from extremely high altitudes. Flowering and fruiting phenology was monitored for 24 plant species at 5,180 m a.s.1, near the base camp area on the north slope of Mt. Qomolangma （Mt. Everest） in Tibet, western China. The dates of first flowering, peak flowering, end of flowering, first fruiting, peak fruiting and flowering period were recorded. There was a wide variation in onset of flowering, long flowering duration, a relative synchrony between the onset of flowering and fruiting, and one species was exclusively vegetative. These results suggest that the species have evolved various phenological strategies as adaptations to the short growing season with limited resources and pollinators in this harsh alpine environment at extremely high elevations. With a background of global warming, local plant species will represent an advancing trend in onset of flowering.
文摘The majority of livestock in the rural areas of Africa are indigenous types that are not well defined as breeds as perceived by the developed world. The animals in this important sector have remained largely uncharacterised and face the risk of genetic dilution due to indiscriminate crossbreeding, breed replacement and neglect. This article uses two examples to describe a system that has been implemented in South Africa that allows indigenous livestock from rural keepers to enter the seed stock industry as recognized breeds. The first example is the indigenous Nguni breed of cattle that has been successfully developed into a seed stock breed, with a society celebrating its 25th anniversary in November 2011. The second example involves the challenges of developing a seed stock industry for some of the unimproved indigenous goat breeds of South Africa. Climate change is expected to have a more extreme effect on southern hemisphere continents than on other continents. Such negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. With the likelihood of global warming, these adapted genotypes can play a very important role in sustainable livestock production.
基金supported by National Research Institutes of Basic Research and Operating Expenses of China (Grant No. 2008Y005)National Basic Research Program of China (Grant No. 2010CB951300)
文摘The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature （Tmin） has risen more than twice as fast as the daily maximum temperature （Tmax） during the 20th century. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to in- vestigate how the crops respond to the Train rise. In particular, no experiment research has reported on how crops respond to the higher night temperature, which was the main trend in the climate warming. Taking winter wheat as the test crop, we investi- gated how the winter wheat growth and yields responded to the higher night temperature. In the field experiments, infrared heaters were used to increase higher night temperature （HNT） by about 2.5℃ in contrast to the normal night temperature （CK） in two whole growth durations of winter wheat in 2008-2009 and 2009-2010 in North China. The results indicated that, com- pared to the CK treatment, winter wheat yield did not decline in HNT treatment, which increased temperatures by 2.0-2.5℃ in both Wanner year （WY） and Colder year （CY）. Furthermore, winter wheat yield in CY increased significantly in HNT treatment. HNT treatment in CY could significantly promote tillering and increase the effective panicles, which increased grain yield significantly （by more than 30% compared with CK）. HNT treatment in CY contributed to an increase in the effective panicles and Kernels significantly, although making a significant reduction in 1000-grain weight, but did not lead to the yield decline. Under the HNT treatment, the whole growth duration of the winter wheat was shortened and the phenological dates were earlier except for the beginning of overwintering; the beginnings of the overwintering phase were postponed substantially and the ends of the overwintering phase were ahead of date compared to CK, which shortened the duration of overwintering considerably. We draw on our own studies to show examples of higher night temperature impact on winter wheat in a relative- ly cold year and relatively warm year in North China. Our results refer to winter wheat in North China, not all main winter wheat producing regions, in Huang-Huai and Southwest of China. Some uncertainties of our predictions derive from fast pro- gress in crop breeding, the variability of climate, and the role of adaptive actions in the future. As expected, the adaptation measures should be considered to cope with the impacts of global warming on crops, and further research and assessments should be conducted.
基金supported by the National Natural Science Foundation of China(41230750,31402121)the National Basic Research Program of China(2013CB956000)+1 种基金the National Key Research and Development Program of China(2016YFC0501802)the China Postdoctoral Science Foundation(2013M541050)
文摘Warming increases competition among plant species in alpine communities by ameliorating harsh environmental conditions,such as low temperatures. Grazing, as the main human activity, may mitigate the effect of warming, as previously reported.However, it is critical to refine the effects of warming on biotic interactions among species, for example, by taking the competitive ability of species into consideration. Based on a 10-year warming and grazing experiment in a Tibetan alpine meadow, we evaluated interspecific biotic interactions of dominant and subordinate species, using the approach of interspecific spatial associations. Warming significantly increased competition between subordinate and dominant species as well as among subordinate species, but not among dominant species. Moreover, facilitation of dominant-subordinate species also increased under warming. Simulated rotational grazing had similar effects to warming, with increasing interspecific competition. Our results show that, when studying the effects of warming on biotic interactions among species, it is necessary to characterize different species pairs relative to their competitive ability, and that simulated rotational grazing does not mitigate the effects of warming in the long term. Our results also provide evidence that the spatial pattern of species is a critical mechanism in species coexistence.
