施肥和补播对甘南退化高寒草甸植物群落特征的影响OA

To identify suitable forage reseeding combinations and organic fertilizer application rates for lightly degraded alpine meadows,a two-factor randomized block experiment was conducted in Luqu County,Gansu Prov-ince.Three reseeding combinations:T1(Elymus nutans+Festuca sinensis),T2(Elymus sibiricus+Festuca sinen-sis),and T3(Elymus nutans+Elymus sibiricus+Festuca sinensis)as well as four organic fertilizer application rates:F0(0 kg/hm2),F1(1 500 kg/hm2),F2(2 250 kg/hm2),and F3(3 000 kg/hm2)to investigate their effects on aboveground biomass,plant community diversity,and stability in lightly degraded alpine meadows.The results showed that both reseeding combinations and fertilization highly significantly affected aboveground biomass in 2023 and 2024(P<0.01).Within T3,aboveground biomass under F3 was 14.87％and 18.47％higher than that under F0 in 2023 and 2024,respectively.The reseeding×fertilization interaction was not significant in 2023,whereas it was highly significant in 2024(P<0.01).In terms of plant community diversity,reseeding significantly affected the Simpson and Shannon-Wiener indices in 2023(P<0.05),while neither fertilization nor the reseeding×fertilization interaction had significant effects.In 2024,reseeding had highly significant effects on species richness and the Shannon-Wiener index(P<0.01),and the reseeding×fertilization interaction significantly affected the Simpson and Shannon-Wiener indices(P<0.05),whereas the main effect of fertilization remained non-significant.Community stability analysis showed that the Euclidean distances between T3-F1 and the stability point were 12.60 and 11.26 in 2023 and 2024,respectively,the smallest values among all treatments,indicating that T3-F1 exhibited the high-est community stability.Grey relational analysis ranked T3-F3 highest in the comprehensive evaluation,with a weighted relational grade of 0.971 4,followed by T3-F2(0.861 1).