Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into...Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into photosynthesis. It is very sensible for factors affecting on vegetation variability such as climate, soils, plant characteristics and human activities. So, it can be used as an indicator of actual and potential trend of vegetation. In this study we used the actual NPP which was derived from MODIS to assess the response of NPP to climate variables in Gadarif State, from 2000 to 2010. The correlations between NPP and climate variables (temperature and precipitation) are calculated using Pearson’s Correlation Coefficient and ordinary least squares regression. The main results show the following 1) the correlation Coefficient between NPP and mean annual temperature is Somewhat negative for Feshaga, Rahd, Gadarif and Galabat areas and weakly negative in Faw area;2) the correlation Coefficient between NPP and annual total precipitation is weakly negative in Faw, Rahd and Galabat areas and somewhat negative in Galabat and Rahd areas. This study demonstrated that the correlation analysis between NPP and climate variables (precipitation and temperature) gives reliably result of NPP responses to climate variables that is clearly in a very large scale of study area.展开更多
Landscape connectivity is a parameter of landscape function, which measures the processes by which the sub populations of organisms are interconnected into a functional demographic unit. It is a landscape phenomenon w...Landscape connectivity is a parameter of landscape function, which measures the processes by which the sub populations of organisms are interconnected into a functional demographic unit. It is a landscape phenomenon which describes the relationships between landscape subunits. Landscape connectivity can be measured by measuring the degree to which the landscape pattern facilitates or impedes movement of animals among resource patches, particularly for conserved animal species. In this paper, the landscape connectivity for Giant Panda in Wolong Nature Reserve was evaluated by using landscape ecological model on the base of choosing three natural affecting factors on Giant Panda and using geographic information system. The results demonstrate that only about 90 36 km 2 (c.a.4 47%) of total area 2023 31 km 2 is most suitable for Giant Panda survival, the suitable area is about 226 42 km 2 (11 19%), the moderately suitable area is 286 09 km 2 (14 13%), as much as 1236 51 km 2 is completely unsuitable for Giant Panda living. The result will be helpful for making a decision on improving eco environment and protecting Giant Panda in Wolong Nature Reserve.展开更多
文摘Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into photosynthesis. It is very sensible for factors affecting on vegetation variability such as climate, soils, plant characteristics and human activities. So, it can be used as an indicator of actual and potential trend of vegetation. In this study we used the actual NPP which was derived from MODIS to assess the response of NPP to climate variables in Gadarif State, from 2000 to 2010. The correlations between NPP and climate variables (temperature and precipitation) are calculated using Pearson’s Correlation Coefficient and ordinary least squares regression. The main results show the following 1) the correlation Coefficient between NPP and mean annual temperature is Somewhat negative for Feshaga, Rahd, Gadarif and Galabat areas and weakly negative in Faw area;2) the correlation Coefficient between NPP and annual total precipitation is weakly negative in Faw, Rahd and Galabat areas and somewhat negative in Galabat and Rahd areas. This study demonstrated that the correlation analysis between NPP and climate variables (precipitation and temperature) gives reliably result of NPP responses to climate variables that is clearly in a very large scale of study area.
文摘Landscape connectivity is a parameter of landscape function, which measures the processes by which the sub populations of organisms are interconnected into a functional demographic unit. It is a landscape phenomenon which describes the relationships between landscape subunits. Landscape connectivity can be measured by measuring the degree to which the landscape pattern facilitates or impedes movement of animals among resource patches, particularly for conserved animal species. In this paper, the landscape connectivity for Giant Panda in Wolong Nature Reserve was evaluated by using landscape ecological model on the base of choosing three natural affecting factors on Giant Panda and using geographic information system. The results demonstrate that only about 90 36 km 2 (c.a.4 47%) of total area 2023 31 km 2 is most suitable for Giant Panda survival, the suitable area is about 226 42 km 2 (11 19%), the moderately suitable area is 286 09 km 2 (14 13%), as much as 1236 51 km 2 is completely unsuitable for Giant Panda living. The result will be helpful for making a decision on improving eco environment and protecting Giant Panda in Wolong Nature Reserve.
