The effect of spatial pattern on the nutrient reduction is investigated based on the spatial simulation model developed for the study area of the Liaohe Delta, China. Four scenarios are designed to test the effect of ...The effect of spatial pattern on the nutrient reduction is investigated based on the spatial simulation model developed for the study area of the Liaohe Delta, China. Four scenarios are designed to test the effect of different landscape components on the nutrient reduction in the reed marsh: Canal density, reed area size, reed area shrinking pattern, and pumping station position. Based on a spatial model designed for the study area, the nutrient reduction in each case of these scenarios is simulated. The results indicate that each factor brings less than 10% change in the total nutrient reduction rate. More canals will not help much to improve nutrient reduction. Smaller areas are more efficient than larger ones. The shrinkage pattern is better than others in keeping a higher nutrient reduction rate. It is also more efficient to keep the pumping station near the border of the area to be irrigated. These conclusions provide theoretical supports to strategy makers for local land use planning, and contribute to the understanding of the relationship between landscape patterns and functions.展开更多
Spatial and temporal characteristics of Zostera marina (eelgrass) in the Barnegat Bay-Little Egg Harbor Estuary are compared before (2004-2011) and after (2012-2013) major fertilizer legislation (Fertilizer Law A2290)...Spatial and temporal characteristics of Zostera marina (eelgrass) in the Barnegat Bay-Little Egg Harbor Estuary are compared before (2004-2011) and after (2012-2013) major fertilizer legislation (Fertilizer Law A2290) was enacted in New Jersey (USA) to reduce nutrient inputs from fertilizers to water bodies in the state. A significant decrease of Z. marina biomass and areal cover occurred in this eutrophic estuary between 2004 and 2011 concomitantly with increasing nitrogen and phosphorus loading from the watershed. The rate of decline in aboveground and belowground biomass was significantly sharper during 2004-2006 than during 2008-2010. In 2010, Z. marina biomass dropped to a very low level (mean aboveground biomass = 7.7 g dry wt m<sup>DŽ</sup>;mean belowground biomass = 27.0 g dry wt m<sup>DŽ</sup>), persisting through the last sampling period (October-November) in 2013. Biomass and areal cover of Z. marina decreased even further after Fertilizer Law A2290 was enacted in January 2012, with the lowest values recorded from August to November each year. These low values are the result of ongoing eutrophication of the system. More seagrass monitoring and research are necessary in future years to determine if the fertilizer law will have a positive effect on Z. marina condition in the estuary over the long term.展开更多
基金National Natural Science Foundation of China, NSFC 49631040, 40001002 Wageningen Agricultural University, the Netherlands Co-s
文摘The effect of spatial pattern on the nutrient reduction is investigated based on the spatial simulation model developed for the study area of the Liaohe Delta, China. Four scenarios are designed to test the effect of different landscape components on the nutrient reduction in the reed marsh: Canal density, reed area size, reed area shrinking pattern, and pumping station position. Based on a spatial model designed for the study area, the nutrient reduction in each case of these scenarios is simulated. The results indicate that each factor brings less than 10% change in the total nutrient reduction rate. More canals will not help much to improve nutrient reduction. Smaller areas are more efficient than larger ones. The shrinkage pattern is better than others in keeping a higher nutrient reduction rate. It is also more efficient to keep the pumping station near the border of the area to be irrigated. These conclusions provide theoretical supports to strategy makers for local land use planning, and contribute to the understanding of the relationship between landscape patterns and functions.
文摘Spatial and temporal characteristics of Zostera marina (eelgrass) in the Barnegat Bay-Little Egg Harbor Estuary are compared before (2004-2011) and after (2012-2013) major fertilizer legislation (Fertilizer Law A2290) was enacted in New Jersey (USA) to reduce nutrient inputs from fertilizers to water bodies in the state. A significant decrease of Z. marina biomass and areal cover occurred in this eutrophic estuary between 2004 and 2011 concomitantly with increasing nitrogen and phosphorus loading from the watershed. The rate of decline in aboveground and belowground biomass was significantly sharper during 2004-2006 than during 2008-2010. In 2010, Z. marina biomass dropped to a very low level (mean aboveground biomass = 7.7 g dry wt m<sup>DŽ</sup>;mean belowground biomass = 27.0 g dry wt m<sup>DŽ</sup>), persisting through the last sampling period (October-November) in 2013. Biomass and areal cover of Z. marina decreased even further after Fertilizer Law A2290 was enacted in January 2012, with the lowest values recorded from August to November each year. These low values are the result of ongoing eutrophication of the system. More seagrass monitoring and research are necessary in future years to determine if the fertilizer law will have a positive effect on Z. marina condition in the estuary over the long term.
