ANALYSIS OF CHANGES IN SHELTERBELT LANDSCAPE IN NORTHEAST CHINA
Applied Ecology and Environmental Research
Understanding the shelterbelt development in northeast China over the past 30 years will provide a scientific decision support for its management in future. In this paper, Landsat images were selected to extract shelterbelt information covering three points in time (1990, 2000 and 2010). Shelterbelt density and landscape indexes (ratio of belt to patch, connectivity, and dominance) were introduced to analyze changes in landscape. Farmland landscape indexes (ratio of farmland to zone and
... to zone and fragmentation) were used to analyze the effect of farmland on shelterbelt distribution and change. The result showed that: (1) shelterbelt density had considerable spatial variation. These changes were strong correlated with land-use type. Farmland fragmentation was a main index which significantly affected the connectivity and evenness of shelterbelt, especially on connectivity; (2) shelterbelt density increased about 10% over the 30 years. This modest increase included two contrasting trends, an increase by 13.2% from 1990 to 2000 followed by a 2.8% reduction by 2010. Even the quantity reduced over 2000-2010, the qualities including connectivity and evenness were getting better overall. The temporal changes of shelterbelt density had little relationship with farmland changes. This research can provide valuable information for decision makers to guide and develop future policies. APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 17(5):11655-11668. by shelterbelt lengths divided into total lengths in each zone. Such changes of the density were closely related to the 3N project. The first phase of this project was from 1978 to 1985. One of the main objectives in this phase was to plant more trees. The second phase from 1986 to 1996 aimed at strengthening gains made during the first phase (Moodre and Russell, 2003). For this reason, the shelterbelt density increased between 1990 and 2000. After 2000, many shelterbelts developed into over-mature forests and, because of destruction by humans, plant disease and insect pests, many shelterbelts were lost and the construction of the agro-forestry system entered updating phase. In this phase, many shelterbelts were updated, and sometimes they were too young to be recognized by remote sensing. Therefore, the density decreased between 2000 and 2010. APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 17(5):11655-11668.