Honghe Hani Terraced Landscape Pattern-process And Mechanism Of Ecological Services

In the context of rapid degradation of global ecosystem services,it is of great significance to reveal the cascading relationship between pattern,process and service function in the supply side to optimize ecosystem services and achieve sustainable landscape development.Here,taking Yuanyang Country,the world cultural landscape heritage site of Hani terrace in Honghe as the research object.Through the decision tree model,minimum cost model-landscape connectivity index,InVEST model,the Bayesian network.etc.The four parts of Hani terrace during 1990-2020 were analyzed,including the evolution characteristice and driving mechanism of landscape pattern,the evolution characteristics of key process among humanities-hydrology-biology,the evaluation and variation characteristics of key ecosystem service function,and the cascade relationship and effect of landscape pattern-process-key ecosystem service function.The main conclusions are as follows:(1)Forestland,dry land and paddy fields were the dominant landscapes in Hani terrace,accounting for 45.8%,33.0% and 18.1%,respectively.In terms of landscape pattern change characteristics,the area of forestland conversion began to increase after 1995 and maintained a relatively high level.The area of dryland decreased significantly from 1990 to 2005,and mainly shifted to forestland.Paddy fields decreased continuously,which was the most severe from 1990 to 2000,relatively flat from 2005 to 2015.The main driving factor of paddy field was temperature(contribution rate78.9%).The main controlling factor of dryland was road distance(contribution rate was 81.1%).The main controlling factor of forestland change was economy and distance from administrative center(contribution rate was 96%).(2)The human process showed an "M"-shaped trend from 1990 to 2020,and peaked in 1995 and 2005.In terms of hydrological process,the hydrological connectivity of Hani terrace showed an overall downward trend(down by 28%)in the past 30 years.The hydrological connectivity was higher in 1990 and 2005,and lower in the rest of the period.In the past 30 years,the hydrological connectivity of the central,eastern and western regions was relatively stable with little change.In terms of biological processes,biological connectedness generally showed an increasing trend and showed a "W"-shaped trend in the past 30 years.In 1995 and 2015,there were two periods of significant decrease,and the other periods were all increased.In space,the center of gravity of biological connectivity in the Hani terrace in the past 30 years has a tendency to shift westward.(3)Grain output,forest by-products and livestock production of Hani terrace all on the increasing trend in the past 30 years.In terms of spatial pattern,it had the characteristics of the spatial pattern of East > Central > West At the same time;The landscape water yield showed forestland > dry land > construction > bare land >grassland > water area > paddy field,which has the spatial characteristics of more in the south and less in the north.From 1900 to 2020,the soil conservation in Hani terrace area was fluctuating,mainly driven by climate change and policy.Forestland contributed 79.18% of carbon storage in the region,followed by paddy land with 11.41%and dry land with 8.87%.In the past 30 years,carbon storage in most areas of the Hani terrace area has increased spatially,with a significant decline mainly in Nansha town.(4)In terms of the cascade relationship of landscape pattern-process-service function,the change of landscape pattern of Hani terrace resulted in the stable probability of human and hydrological processes(50.3% and 58.5%),and the high probability of increase in biological processes(51.7%).Under the combined effect of pattern and process,the probability of carbon storage service function remained stable(51.6%).The probability of water production and soil conservation service function increased(71.2% and 56.2%),and the probability of food supply service function decreased(90.3 %).It can be found that the landscape pattern changes in the past 30 years of Hani terrace were more conducive to the development of natural processes and service function,that is,the human-land relationship in the Hani terrace area is more harmonious and ecologically more civilized.