In order to gain a more comprehensive understanding of institutional change, researchers need to go beyond a snapshot view of significant events but consider events in their temporal setting. Pierson （2004） advocate...In order to gain a more comprehensive understanding of institutional change, researchers need to go beyond a snapshot view of significant events but consider events in their temporal setting. Pierson （2004） advocated that the events that lead to institutional change should be placed in a moving temporal context, as this will not only add to our comprehension of the dynamics of change, but also enrich the existing research and enhance the theories we employ to give meaning to these events. Pierson （2004） laid the foundation for the research that was later developed by Thelen （2009） that considered incremental endogenous shifts in institutional thinking that can often result in fundamental transformations. The central issues of Pierson＇s （2004） thesis lay in his interpretation of history and its relationship with path dependence. He claimed that once an institution has chosen a particular path to follow, it can become locked into that pathway and so the options of choice are restricted. This then presumed that an institutions first choice of action is crucial to whether they become locked into a successful course of action or not. The result of the first choice being successful or not would be dependent on the presence of increasing returns. The explication Pierson proffers of increasing returns is different to an economic one in that it is based on positive feedback processes and politics in time. The implications of Pierson＇s work and those that followed have a very serious place in our understanding of institutional change.展开更多
The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has im...The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.展开更多
文摘In order to gain a more comprehensive understanding of institutional change, researchers need to go beyond a snapshot view of significant events but consider events in their temporal setting. Pierson （2004） advocated that the events that lead to institutional change should be placed in a moving temporal context, as this will not only add to our comprehension of the dynamics of change, but also enrich the existing research and enhance the theories we employ to give meaning to these events. Pierson （2004） laid the foundation for the research that was later developed by Thelen （2009） that considered incremental endogenous shifts in institutional thinking that can often result in fundamental transformations. The central issues of Pierson＇s （2004） thesis lay in his interpretation of history and its relationship with path dependence. He claimed that once an institution has chosen a particular path to follow, it can become locked into that pathway and so the options of choice are restricted. This then presumed that an institutions first choice of action is crucial to whether they become locked into a successful course of action or not. The result of the first choice being successful or not would be dependent on the presence of increasing returns. The explication Pierson proffers of increasing returns is different to an economic one in that it is based on positive feedback processes and politics in time. The implications of Pierson＇s work and those that followed have a very serious place in our understanding of institutional change.
基金National Natural Science Foundation of China(4117111640961038)
文摘The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.
