Application Of The PSR Model On The Assessment Of Non-resident Island Ecosystem After Development

The ocean is an integral part of our country's territory,with incalculable natural resources.With the continuous development of China's economy and the orderly promotion of the exploitation and utilization of resources,the imbalances between the limited supply of land space and resources and the continuing demand for human development activities have increased year by year.People slowly move their eyes from land to sea,it is more and more aware of the importance of the ocean that occupies more than 70% of the earth's surface area in the natural environment and the importance of the marine economy in the society and economy.The activities of developing and utilizing the ocean are increasing year by year.The island is an important geographic unit in the ocean,and belongs to a part of the ocean.Island can be divided into island and non-resident island in accordance with the permanent residents.There are fewer islands in this area,and more than 90% of the islands are non-resident island.The average area of the island is relatively narrow.The geographical location is far away from the mainland,and the structure of the island is relatively simple.The limited area makes it have fewer plant resources and animal resources,lower biological diversity,low overall environmental carrying capacity,simple ecological structure,and weak anti-interference.After being disturbed by human development activities,the ecosystem is extremely vulnerable to damage.The island ecosystem is different from the common terrestrial ecosystem and the marine ecosystem,at the same time,it is affected by the interaction between the island land and the surrounding sea area,and forms the island ecosystem with the characteristics of two types of ecosystems,both marine and land.The sea and land particularity of the island ecosystem makes its ecosystem very fragile.The development and utilization of China on the island since the end of last century,the development of the way is rough and predatory,do notpay attention to the ecological protection of the island,the lack of relevant ecological research.At present,there were few researches on island ecosystem evaluation in China.Most of them were concentrated on larger islands with residents.They were still at the exploratory stage in the selection of ecological evaluation indicators,and no standard and effective evaluation system had been formed.The evaluation method of island ecosystem is not mature enough and needs further improvement and research.In this paper,we used the "pressure-state-response"(PSR)model to analyze the ecosystem of the non-resident islands according to the pressure characteristics of the development activities of the uninhabited islands by selecting specific evaluation indexes.A set of evaluation index system for non-resident islands was constructed.Taking Tiaowei island as an example,we analyzed the ecological status of 2015 and 2016 years' Tiaowei island and explored the ecological impact of developing island by applying the evaluation and evaluation index system.It was mainly divided into the following aspects:(1)Theoretical research in the related fields both at home and abroad.Firstly,we studied the theories of island characteristics and island development activities at home and abroad,and understand the main types of non-resident islands and their development activities,and their impact on the island ecosystem.Secondly,refer to the related literatures on island ecological assessment,we understanded the main points and methods of island ecosystem assessment,and grasp the research status in related fields at home and abroad.(2)The classification of uninhabited island development activities was divided into four categories according to the different purposes of human development activities on non-resident islands: to travel to the island tourism development activities,industrial development of the island activities,with the aim of developing fishery resources for fishery development activities to the island and other types of island development.(3)The non-resident islands ecosystem was subdivided into ithree parts: the island land ecological character subsystem,the intertidal ecosystem subsystem and the adjacent sea area ecological subsystem.According to the principles of index selection and the main purpose of island development activities,combined with the actual situation of uninhabited islands,we choosed appropriate evaluation indicators to build PSR evaluation model of uninhabited islands.(4)Taking the Tiaowei island as an example,the ecological evaluation of the island was carried out using the constructed PSR evaluation system for the uninhabited island.The survey data of 2015 and 2016 years were selected to analyze the ecological conditions of the islands for two years.The results showed that:compared with the 2015,the score of the ecological system status of the Tiaowei Island changed from 0.65 to 0.58 in2016,and the score grade changed from good to general.It shows that the human activities such as nuclear power development had a certain damage to the ecology of the Tiaowei Island,and the biological growth and development of the island and the surrounding sea area had been greatly affected.The index of abiotic environmental status changed from0.98 to 0.94,which belongs to normal fluctuation.The grading scale was excellent,the oil and heavy metal ions in seawater and sediment were extremely low,and the eutrophication of seawater was relatively slight.It showed that the abiotic environment in the sea area around the tailing island was not polluted.The score of the landscape pattern index changed from 0.66 to 0.43,and the grading grade had a bad change.It shows that the overall landscape pattern of tailing island had been destroyed.The degree of habitat fragmentation was high,and the overall naturalness was low.On the whole,the comprehensive index of island ecosystem in Tiaowei Island changed from 0.79 to 0.71,from the "excellent" level to the middle level of "good" level,and dropped by nearly half.It showed that Tiaowei island is affected by human development activities.Although it has maintained a good state for a while,the landscape pattern had been destroyed,and the biodiversity of the island had been affected.The level of the whole ecosystem is decreasing year by year.