Effects Of Landscape Pattern Dynamics On The Habitat Of Migratory Waterbirds

Henan Xinxiang Yellow River wetland national nature reserve is an important bird nature reserve in the central plains.Due to human activities and natural factors,the changes of structure and function of Xinxiang Yellow River wetland were obvious,the wetland landscape functions had been great changes,The ecological environment of wetland appeared the trend of deterioration had caused distinct ecological effects on water birds' habitats,migration and propagation.while also had an great inpact in the protection of birds reserve,and biodiversity maintenance.Supported by the technique of remote sensing and geographical information system,this research used TM images of Xinxiang Yellow River wetland in 1990,2000 and 2014 as the data sources to acquire the data of wetlands.Based on remote sensing and geographic information systemst echnology,we analyzed the current characteristies and main problems of the wetland ecosystem.Using the existing data on wintering waterfowls pecies and quantity variation,we choosed and quantified the factors impacting on wetland waterfowl habitat,established and evaluated the suitability model(HSI)in order to know the habits of representative watefowl in Xinxiang Yellow River wetland reserve.At the same time,based on the relevant results of the HSI model,using the biodiversity option of InVEST model to assess the habitat degradation,habitat quality and terrestrial ecological quality of the conservation area.Finally,in view of the evaluation results of the waterbirds habitats,this paper put forward to the effective management of related countermeasures and methods which advanced to the study area in the future.The main conclusions of this study could be briefed as follows:(1)Through analyzing three reserve periods of spatial and temporal variations of landscape pattern analysis,The area of natural wetland reduced year by year,while the area of artificial wetland increased greatly;the farmland was the biggest advantage of the research region types which was more than 50%of the total reserve;the proportion of lakes or canals was relatively small,which was less than 10%;the areas of the Yellow River,beaches and ditches declined obviously,while the area of pits increased significantly;During the study period,on the landscape type level,patch density(PD)in the study area increased,largest patch index(LPI)and the average patch area(AREA-MN)declined significantly,landscape types tended to be fragmented;On the landscape level,landscape diversity index(SHDI)and the diversity index(SHEI)decreased,the landscape pattern of the entire study area toward the equalization and simplification direction;The changes of wetland landscape pattern were the results of the combinations of the runoff volume of the yellow river,precipitation,temperature,natural and social factors.In future,we plan to continue studying on the effects of landscape changes on wetland ecosystem.We hope our studies can provide study basis and useful measures for protecting bird habitats and Yellow River wetland ecosystem.(2)The habitat factors of waterbirds in Xinxiang Yellow River wetland reserve characteristics were analyzed,and the results showed that:during the study period,the protected habitat disturbance intensity increased,and the interference degree of larger habitat area was gradually expanded,without interference,the habitat and mild types of habitat area significantly decreased significantly,the moderate interference and interference types of habitat area present the obviously increasing trend;Perennial water and seasonal water habitat area is gradually reduced,and the wet and dry area of landscape types increased significantly;On the vegetation coverage,appropriate and suitable habitat area was declined,the suitable and unsuitable habitat area was increased.The reserve habitat suitability of the research results showed that during 1990-2000,due to the lower reaches of the Yellow River,the protected area,such as the lakes,yellow river,which were suitable for waterbirds survival habitat area were reduced,the suitable habitats turn to the not suitable habitats for the waterbirds such as the forest land,construction land;During 1990-2000,fields such as micro suitable habitat increased slowly,the construction land presented the trend of fragmentation,the degree of landscape fragmentation of the reserve intensify;In 2000-2014,the suitable habitat area for waterbirds in Xinxiang Yellow River wetland reserve was reduced at the same time,the degree of fragmentation was also further intensified,waterbirds habitats environment suffered threatened.(3)The valuing results through InVEST showed that:During 1990-2014,the whole habitat degradation degree of Xinxiang Yellow River wetland reserve was low,but the yellow river,the beaches and other natural wetland types of habitat degradation degree was higher.During the study period,the study area habitat degradation degree higher overall declining habitat area,and gradually tended to be more uniform layout,degradation degree relatively less;Xinxiang Yellow River wetland reserve the overall habitat quality at lower levels,the region's overall degree of landscape fragmentation,fragile ecological environment.The lake,yellow river and other natural wetland landscapes kept high habitat quality,and the surrounding the natural wetland landscape types were habitat quality.In addition,the study area of habitat quality high also reduced year by year,during the study period,the overall habitat quality a downward trend in the study area;the stability of Xinxiang Yellow River wetland reserve was poorer,landscape type change more frequently,scarcity scored highest value increased,habitat scarcity is also further deepened.Reserve,in general,the overall scarcity level was still at a higher level,especially the Yellow River beaches,lakes,natural wetland,such as the score of habitat scarcity was higher and the changes were frequently,the degreel of habitat scarcity was higher.