Dynamic Response Of Invertebrate Community To The Plant Economics Spectrum During Coarse Woody Debris Decomposition In Forests Of Eastern Zhejiang Province

Coarse woody debris(CWD)as an important structural and functional component of forest ecosystem,plays a key role in maintaining nutrient cycling and biodiversity.It was found that plant economics spectrum that mediated by bark and xylem functional trait have a significant "after-life effect",which determines the CWD decomposition rate variation among different species,and has a profound impact on the community structure and dynamic processes of invertebrates.In addition,the different feeding preferences of bark and xylem displayed by invertebrates can also affect this process.However,there is a lack of in-depth studies on how bark and xylem economics spectrum regulate the spatial-temporal dynamics of invertebrate diversity during CWD decomposition.Besides it is not clear whether the relative importance of bark and xylem economics spectrum to spatial-temporal variation of soil invertebrate diversity remain consistent with the CWD decomposition process.Based on these,we carried out a long-term decomposition control experiment in Tiantong and Putuo mountain,Zhejiang Province.We chose 24 common tree species CWD(diameter?20 cm)with two life forms of conifers and broadleaf and different growth strategies as the research object.By measuring bark and xylem functional traits,bark and xylem economics spectrum was constructed,respectively.The invertebrate taxonomic group was investigated and individuals' number and was counted,while the body length,body width was measured,and the feeding guild of invertebrates and defined among different tree species across three and half year during the CWD decomposition process.Based on above investigated and measured data,we calculated taxonomic and functional diversity of invertebrates,analyzed the relationships of bark and xylem economics spectrum and invertebrate ? diversity at different decomposition periods.The replacement pattern of invertebrate diversity between tree species and between years(? diversity)was also revealed.The main results are as follows:1.A total of 92738 invertebrates from 107 taxa,9 classes,30 orders,3 phyla were collected.Among them,Blattodea,Hymenoptera,Collembola and Acarina were the dominant orders of invertebrates throughout CWD decomposition periods.Compared with bark economics spectrum,xylem economics spectrum plays a key role in regulating invertebrate abundance and ? diversity variation during CWD decomposition.In Putuo site,xylem economics spectrum was positive related to the total number of invertebrates,the decomposers abundance and taxonomic richness at the decomposition period of one and a half years,while xylem economics spectrum was negative related to them at the decomposition period of three and a half years.In Tiantong site,while there are positive relationships between xylem economics spectrum and the total number of invertebrates,the decomposers abundance and taxonomic richness at both decomposition periods of one and a half years,and three and a half years.However,for conifer species,xylem economics spectrum did not significantly affect total individuals of invertebrates,the decomposers abundance and taxonomic richness.Besides,bark and xylem economics spectrum had little effect on functional composition and diversity of invertebrates.2.The temporal functional ? diversity of invertebrates was significantly higher than that of taxonomy during CWD decomposition,in which the temporal functional ?diversity was dominated by nestedness components,while the temporal taxonomic ?diversity was dominated by turnover components.Taxonomic and functional temporal? diversity were not always coupled.At the same time,xylem economics spectrum was also the key factor affecting invertebrates' temporal ? diversity.In general,the more acquisitive the species is,the lower temporal ? diversity and the slower turnover component it has,while the temporal functional ? diversity was not regulated by bark and xylem economics spectrum.3.The functional ? diversity of invertebrates was significantly higher than that of taxonomy in the three decomposition periods.Turnover components dominated taxonomic ? diversity while nestedness components dominated functional ? diversity.In general,economics spectrum significantly affected functional but not taxonomic ?diversity,and bark economics patterns also had strong effects.In conclusion,this study introduced the new concept of "after-life effect" of plant economic spectrum and systematically revealed the importance of bark and xylem economics spectrum in regulating invertebrate community structure and dynamics at early decomposition stage of common forest coarse dead wood species in eastern Zhejiang province.Our study showed that the number,functional composition and temporal dynamics of invertebrates involved in the decomposition of coarse woody debris were significantly dependent on the differences of physical and chemical substrates among different tree species.These results suggest that bark and xylem economics spectrum are the main drivers of the spatial-temporal variation of invertebrate diversity during coarse woody debris decomposition process,and the spatial-temporal changes of food resource niche driven by the quality difference of coarse woody debris is the main mechanism of invertebrate diversity.Therefore,this study deepens our understanding of the relationship between plant-invertebrate interactions of coarse woody debris and provides experimental evidence for revealing the biological mechanisms of material cycling in subtropical forest ecosystems.