关键词: 榆树疏林, 人类活动, 土壤环境, 植物多样性

Abstract: To fully and rationally exploit local living marine resources while have a sustainable,efficient and healthy development of shellfish culture in the Dadeng Island sea area of Xiamen,this paper determined and analyzed the related model parameters of this area,including chlorophyll a,primary productivity,phytoplankton organic carbon content,wild filter feeder yields in subtidal and intertidal zones and suspension culture area,cultured shellfish filtration rate and organic carbon content,shellfish's total weight to fresh meat ratio,and adopted the Nutrient Dynamic Model and Coastal Waters' Energy Flow Analysis Model to estimate the ecological capacity of shellfish in this area,from which,the wild filter feeder yields were deducted for estimating shellfish carrying capacity.The model established by Fang Jianguang was also used to estimate the shellfish carrying capacity.Statistics analysis was used to estimate the suitable culture area of shellfish and other species,aiming at limiting local shellfish culture and optimizing the culture of various species mollusks.According to the estimation of the three models,the shellfish carrying capacity in this area should be 35 248～39 990 tons,with an average of 37 488 tons,and 140 008×10⁴～158 850×10⁴ individuals,averaging 148 903×10⁴.The theoretically suitable culture area was 2 145 hm²,1 900 hm² for Ostreidae,81 hm² for razor clam (Sinonovacula constricta),20 hm² for blood clam (Tegillarca granosa),and 144 hm² for musculus (Musculus senhousei).In 2000,the actual culture area of shellfish and other species in the waters around Dadeng surpassed the estimated suitable culture area.It is proposed that some measures should be taken to reduce the verexploited area.

Key words: Elm sparse woods, Human activity, Soil environment, Plant species diversity