Long-term impacts of Cervus nippon on plant community and soil organic carbon accumulation.

Abstract

Large animal activities directly affect forest ecosystems. To understand the impact of Cervus nippon activi-ties on the ecosystem function of the reserve, we investigated the interrelationships among plant community structure, soil physico-chemical properties, and soil organic carbon stocks (SCS) under the interference of C. nippon in a mixed conifer-broadleaved forest located in Qianqingtang of Zhejiang Qingliangfeng National Nature Reserve, Zhejiang Province. The results showed that the aboveground biomass of understory decreased with increasing duration (10, 15 and 20 years) of C. nippon captivity, with significantly higher biomass in the forbidden area than each captive area. Plant communities in the captive areas were simpler and more homogeneous than the forbidden area. SCS and organic carbon content in the C. nippon captive area were 10.6%-54.3% and 22.7%-64.5% lower, respectively, than those in the forbidden area. SCS decreased with increasing years of C. nippon disturbance. Additionally, aboveground biomass and its importance values were positively correlated with SCS. Plant factors demonstrated significant direct positive effects on soil nutrients (total potassium and available nitrogen) and SCS, with effect values of 0.818 and 1.076, respectively. The years of C. nippon captivity showed a significant indirect negative effect on SCS (-1.207), a highly significant direct positive effect on soil bulk density (0.926), and a markedly significant direct negative effect on plant factors (-1.069). In summary, the long-term disturbance of C. nippon within a limited range may reduce soil nutrients and SCS in the surface soil by destroying plant community and altering soil structure. Therefore, it was recommended to reconsider and expand the scope of protection for C. nippon to foster the harmonious development of both forests and wildlife.