This study explores the role of a traditional tillage method,i.e.,compensatory hoeing,for sustainable agro-ecosystem management in the hilly areas of the Chongqing municipality,south-western China.To validate the effe...This study explores the role of a traditional tillage method,i.e.,compensatory hoeing,for sustainable agro-ecosystem management in the hilly areas of the Chongqing municipality,south-western China.To validate the effects of compensatory tillage on the terraced slopes,the tillage method of noncompensatory hoeing was conducted on a linear slope.To acquire information about 137 Cs inventories and soil texture,soil samples were collected by a core sampler with a 6.8-cm diameter at 5.0-m intervals along the toposequence and the linear slope in the dry season(March) of 2007.Meanwhile,a tillage erosion model was used for evaluating the spatial pattern of tillage erosion.The 137 Cs data showed that on the terraced slope,soil was lost from the upper slope,and soil deposition occurred at the toe slope positions on each terrace.As a result,abrupt changes in the 137 Cs inventories of soil were found over short distances between two sides of terrace boundaries.Results obtained from the tillage erosion model and the 137 Cs data indicate that soil redistribution mainly results from tillage erosion in the terraced landscape.Consecutive non-compensatory tillage caused soil redistribution on the linear slope,resulting in thin soil profile disappearing at the top and soil accumulating at the bottom positions of the linear slope.This result further validates that compensatory tillage could avoid the complete erosion of the thin soil layer at the summit position.Therefore,this traditional tillage.method,i.e.,compensatory tillage,has maintained the soil quality at the summit of the slope in the past decades.展开更多
Paramo is a term used to describe tropical alpine vegetation between the continuous timberline and the snow line in tbe Northern Andes. Paramo environments provide important species habitat and ecosystem services. Cha...Paramo is a term used to describe tropical alpine vegetation between the continuous timberline and the snow line in tbe Northern Andes. Paramo environments provide important species habitat and ecosystem services. Changes in spatial extent of the paramo ecosystem at Pambamarca in the Central Cordillera of the northern Ecuadorian Andes were analysed using multi-temporal Landsat TM/ETM＋ satellite data. The region suffered a loss of 1826.6 ha or 20% of the total area at a rate of 100 ha/annum during 1988-2007 period. It is found that permanent paramo cover decreased from 8350 ha in 1988 to 5864 ha in 2007 at a fairly constant rate （R^2=0.94）. This loss is attributed to expansion of commercial agriculture and floriculture in the valleys coupled with increased population pressure. Land at higher elevations has been cleared for small scale agriculture. Loss of the paramo ecosystem will exert a number of negative impacts on ecosystem services and livelihoods of the local population at Pambamarca.展开更多
基金provided by the Special Support Foundation of the Institute of Mountain Hazards and Environment (IMHE)the 100 Talents Programme of IMHE,Chinese Academy of Sciences (No. SDSQB-2011-01)
文摘This study explores the role of a traditional tillage method,i.e.,compensatory hoeing,for sustainable agro-ecosystem management in the hilly areas of the Chongqing municipality,south-western China.To validate the effects of compensatory tillage on the terraced slopes,the tillage method of noncompensatory hoeing was conducted on a linear slope.To acquire information about 137 Cs inventories and soil texture,soil samples were collected by a core sampler with a 6.8-cm diameter at 5.0-m intervals along the toposequence and the linear slope in the dry season(March) of 2007.Meanwhile,a tillage erosion model was used for evaluating the spatial pattern of tillage erosion.The 137 Cs data showed that on the terraced slope,soil was lost from the upper slope,and soil deposition occurred at the toe slope positions on each terrace.As a result,abrupt changes in the 137 Cs inventories of soil were found over short distances between two sides of terrace boundaries.Results obtained from the tillage erosion model and the 137 Cs data indicate that soil redistribution mainly results from tillage erosion in the terraced landscape.Consecutive non-compensatory tillage caused soil redistribution on the linear slope,resulting in thin soil profile disappearing at the top and soil accumulating at the bottom positions of the linear slope.This result further validates that compensatory tillage could avoid the complete erosion of the thin soil layer at the summit position.Therefore,this traditional tillage.method,i.e.,compensatory tillage,has maintained the soil quality at the summit of the slope in the past decades.
文摘Paramo is a term used to describe tropical alpine vegetation between the continuous timberline and the snow line in tbe Northern Andes. Paramo environments provide important species habitat and ecosystem services. Changes in spatial extent of the paramo ecosystem at Pambamarca in the Central Cordillera of the northern Ecuadorian Andes were analysed using multi-temporal Landsat TM/ETM＋ satellite data. The region suffered a loss of 1826.6 ha or 20% of the total area at a rate of 100 ha/annum during 1988-2007 period. It is found that permanent paramo cover decreased from 8350 ha in 1988 to 5864 ha in 2007 at a fairly constant rate （R^2=0.94）. This loss is attributed to expansion of commercial agriculture and floriculture in the valleys coupled with increased population pressure. Land at higher elevations has been cleared for small scale agriculture. Loss of the paramo ecosystem will exert a number of negative impacts on ecosystem services and livelihoods of the local population at Pambamarca.
