■塔吉克斯坦是一个典型的山区国家,覆盖着不同的山地草原,这些草原是重要的牧场资源。最近,由于气候变化和人类活动,草地退化已变得普遍,施肥已被用于提高草地产量。然而,化肥投入可以显著改变物种多样性,但这还不清楚生产力和物种多样性如何对塔吉克斯坦山区草甸的养分富集做出反应。
■因此,进行了为期5年(2018-2022年)的连续原位矿物肥料实验,以检查三种氮(N)水平(0、30和90kgNha-1year-1)的影响,两种磷(P)水平(0和30kgPha-1year-1),以及它们对Ziddi山地草甸草地地上生物量(AGB)和物种多样性的组合,Varzob区域,塔吉克斯坦。五个物种多样性指标-Margalef的物种丰富度(Dma),香农-维纳指数(H),辛普森指数(C),Pielou的公平性指数(Epi),和Evar物种均匀度指数(Evar)-用于测量物种多样性。
■结果表明,添加不同的N和P量及其各种组合大大增加了总和优势种AGB,2022年N90P30(90kgNha-1year-1结合30kgPha-1year-1)治疗的增幅最高;在实验期间,Prangospabularia(优势种)的重要性值先降后升,但是它的主导地位在几年中没有变化或波动。此外,N,P,它们的不同组合对物种多样性没有显著影响(Dma,H,C,Epi,和Evar)。所有物种多样性指数都在不同年份波动,但与矿物肥料的添加没有相互作用。总AGB与物种多样性呈负相关,低浓度氮肥(N30;P30)增强了这种负趋势。然而,在高氮肥条件下(N90P30),这一趋势下降。总的来说,Varzob地区天然山地草地的养分添加提高了AGB,这意味着当地动物有更多的饲料。矿物肥料对物种多样性没有显著影响,但将来可能会增强P.pulbularia的优势,这将有助于维持植物群落的稳定并提高牧草的质量,因为P.pullaria是一种优良而重要的冬季饲料。我们的研究表明,科学的养分管理可以有效地促进草地生产。保存植物品种,再生退化的草地,这将抵消塔吉克斯坦西北部山区草甸的荒漠化进程。
UNASSIGNED: Tajikistan is a typical mountainous country covered by different mountain grasslands that are important pasture resources. Recently, grassland degradation has become widespread due to climate change and human activities and fertilization has been used to improve grassland production. However, fertilizer inputs can substantially alter species diversity, but it is uncl\\ear how productivity and species diversity respond to nutrient enrichment in the mountain meadows of Tajikistan.
UNASSIGNED: Therefore, a 5-year (2018-2022) continuous in-situ mineral fertilizer experiment was conducted to examine the effects of three nitrogen (N) levels (0, 30, and 90 kg N ha-1 year-1), two phosphorus (P) levels (0 and 30 kg P ha-1 year-1), and their combinations on above-ground biomass (AGB) and species diversity in a mountain meadow grassland in Ziddi, Varzob region, Tajikistan. Five species diversity metrics-Margalef\'s species richness (Dma), the Shannon-Wiener index (H), the Simpson index (C), Pielou\'s equitability index (Epi), and the Evar Species Evenness index (Evar)-were used to measure species diversity.
UNASSIGNED: The results indicated that the addition of different N and P amounts and their various combinations considerably increased both total and dominant species AGB, with the highest increase occurring in the N90P30 (90 kg N ha-1 year-1 combined with 30 kg P ha-1 year-1) treatment in 2022; during the experiment, the importance value of Prangos pabularia (dominant species) first decreased and then increased, but its dominant status did not change or fluctuate among the years. Furthermore, N, P, and their different combinations had no significant effect on species diversity (Dma, H, C, Epi, and Evar). All the species diversity indexes fluctuated among years, but there was no interaction with mineral fertilizer addition. Total AGB had a negative relationship with species diversity and low concentration N fertilizer addition (N30; P30) strengthened this negative trend. However, this trend decreased under the high N fertilizer condition (N90P30). Overall, nutrient addition to the natural mountain grassland of the Varzob region improved AGB, which meant that there was more forage for local animals. Mineral fertilizers had no significant effect on species diversity, but may enhance P. pabularia dominance in the future, which will help maintain the stability of the plant community and improve the quality of the forage because P. pabularia is an excellent and important winter fodder. Our study suggests that scientific nutrient management could effectively promote grassland production, conserve plant variety, and regenerate degraded grassland, which will counteract the desertification process in northwest Tajikistan mountain meadows.