配比施肥对带状采伐毛竹林林下植被多样性的影响

[Objective]Moso bamboo is an important tree species with integrated economic and ecological values,and strip harvesting is considered feasible as a relatively new efficient and mechanizable management model to accelerate stand recovery through nutrient input on the basis of natural recovery after harvesting.[Method]In 2019,pure stands of old-growth moso bamboo were selected,three fertilization ratios of N:P2O5:K2O=2:1:1,3.5:1:2,and 5:1:2.5(A1,A2,A3)and three fertilization application rates of 450,600,and 750 kg·hm-2(B1,B2,B3)from and a two-factor,three-level experiment was set up to investigate the response mechanism of understory vegetation diversity to nutrient input and to analyze the variability and correlation.[Result](1)In the year of harvesting,the vegetation diversity of understory vegetation increased with the proportion of N and K fertilization applied,and the Shannon index(H)and Gleason species richness index(D′)showed a significant increasing trend,showing bimodality compared with the control treatment,and the Simpson index(D)and Pielou evenness index(E)showed a significant single-peaked trend,and the differences of each index by different fertilization application were not significant.(2)The significant trend of H and D′ disappeared in 2021.D and E maintained a significant single-peak trend,peaking at the fertilization application ratio of A2.(3)In terms of temporal dynamics,the effect of treatments on understory vegetation diversity showed a pattern of"promotion followed by suppression",with H,D′ and D in 2021 showing a decreasing trend and E an increasing trend compared to 2019.(4)The biomass of understory vegetation was affected by fertilization treatments similarly to diversity and was closely correlated,with fertilization application significantly increasing the biomass of understory vegetation in the year after logging,with significant inhibition occurring in the first major year after logging and the lowest biomass under A2 fertilization application ratio.[Conclusion]Therefore,fertilization can promote the growth of understory vegetation and increase species diversity.And under the fertilization treatment with the ratio of N:P2O5:K2O=3.5:1:2,the nutrients were more fully utilized by the understory vegetation,which was conducive to improving the stability of the moso bamboo stand and achieving sustainable development.