Limits...
Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China.

Zhang J, Wang T, Ge J - PLoS ONE (2015)

Bottom Line: In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide.The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI.Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology & College of Life Sciences, Beijing Normal University, Beijing, PR China; Earth and Environmental Sciences Department, Lehigh University, Bethlehem, Pennsylvania, United States of America.

ABSTRACT
In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China's afforestation program.

No MeSH data available.


Related in: MedlinePlus

Time series of runoff volume (a) and sediment yield (b) measured at seven hydrological stations along the main stream of Yangtze River.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4482633&req=5

pone.0131352.g009: Time series of runoff volume (a) and sediment yield (b) measured at seven hydrological stations along the main stream of Yangtze River.

Mentions: We evaluated the runoff volume and sediment yield in the gauging stations to determine if an obvious decrease occurred in response to the recent changes in vegetation. The average runoff volume of the seven stations shows a decreasing but not significant trend (R2 = 0.32, p > 0.50) (Fig 9A). Records of runoff volume from all stations in 2006 were low due to the shortage of precipitation that year. The average sediment yield at the seven hydrologic monitoring stations show a significant decrease (R2 = 0.72, p < 0.01) while no precipitation trends were observed for this period (Fig 9B). From 2000 to 2004, the decreasing trend of sediment yield was significant and persistent. However, the sediment yield increased sharply at all stations in 2005, which may be the result of high precipitation from the strong El Niño year. The sediment yield of all stations in 2006 was relatively low due to the correspondingly less precipitation. From 2007 to 2011, all seven stations showed a decreasing trend in sediment yield, albeit less significant than that from 2000 to 2004.


Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China.

Zhang J, Wang T, Ge J - PLoS ONE (2015)

Time series of runoff volume (a) and sediment yield (b) measured at seven hydrological stations along the main stream of Yangtze River.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482633&req=5

pone.0131352.g009: Time series of runoff volume (a) and sediment yield (b) measured at seven hydrological stations along the main stream of Yangtze River.
Mentions: We evaluated the runoff volume and sediment yield in the gauging stations to determine if an obvious decrease occurred in response to the recent changes in vegetation. The average runoff volume of the seven stations shows a decreasing but not significant trend (R2 = 0.32, p > 0.50) (Fig 9A). Records of runoff volume from all stations in 2006 were low due to the shortage of precipitation that year. The average sediment yield at the seven hydrologic monitoring stations show a significant decrease (R2 = 0.72, p < 0.01) while no precipitation trends were observed for this period (Fig 9B). From 2000 to 2004, the decreasing trend of sediment yield was significant and persistent. However, the sediment yield increased sharply at all stations in 2005, which may be the result of high precipitation from the strong El Niño year. The sediment yield of all stations in 2006 was relatively low due to the correspondingly less precipitation. From 2007 to 2011, all seven stations showed a decreasing trend in sediment yield, albeit less significant than that from 2000 to 2004.

Bottom Line: In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide.The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI.Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology & College of Life Sciences, Beijing Normal University, Beijing, PR China; Earth and Environmental Sciences Department, Lehigh University, Bethlehem, Pennsylvania, United States of America.

ABSTRACT
In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China's afforestation program.

No MeSH data available.


Related in: MedlinePlus