天山中部天山云杉林土壤种子库海拔梯度分布格局

【目的】通过对天山北坡中部海拔1 450～2 750 m高度天山云杉林土壤种子库的采样与分析,深入了解天山云杉林土壤种子库的海拔梯度分布格局,以期为天山森林生态系统的保育恢复与可持续管理提供科学依据。【方法】采用野外土壤种子库采样与室内萌发相结合的方法,对土壤种子库物种组成及种子数量进行鉴定。【结果】从天山云杉林土壤种子库中共萌发鉴定出种子植物49种,隶属23科38属。随着海拔高度上升,天山云杉林土壤种子库的物种组成数量总体上呈现波动中下降的趋势,最大值出现在海拔2 000 m(1 950～2 050 m),达到30种;相邻海拔梯度之间共有物种数量呈现先增加后下降,最后趋于平稳;土壤种子库种子密度呈现单峰分布格局,密度最大值(1 813.8±154.0粒/m2)出现在海拔2 000 m(1 950～2 050 m);土壤种子库中天山云杉种子密度也呈现单峰分布格局,密度最大值(190.0±16.8粒/m2)出现在海拔1 800 m(1 750～1 850 m)。【结论】随着海拔高度上升,天山云杉林土壤种子库的物种组成数量总体上呈现波动中下降的趋势。天山云杉林土壤种子库种子密度和土壤种子库中天山云杉种子密度随着海拔高度上升均呈现单峰分布格局,但二者在海拔垂直空间分布上不具有同步性。

Distribution Patterns of Soil Seed Bank of Picea Schrenkiana Forests along the Altitudinal Gradient in the Central Section of Tianshan Mountains,Xinjiang

【Objective】 Through the sampling and analysis on Picea schrenkiana forests soil seed bank at an altitude from 1,450 m to 2,750 m on the central northern slope of Tianshan Mountains,the research aimed at in-depth understanding of the distribution pattern of the soil seed bank along the altitudinal gradient,thus it can provide scientific basis for forest ecosystem conservation,restoration and sustainable management in Tianshan Mountains.【Method】Combined with soil seed bank sampling and laboratory germination,in order to identify the species composition of soil seed bank and seed quantity.【Result】Through the germination of P.schrenkiana forests soil seed bank,we identified 49 species of seed plants,belonging to 23 families and 38 genera.With the altitude rising,the number of species composition of P.schrenkiana forests soil seed bank shows a declining trend in the fluctuation as a whole.At the altitude of 2,000 m(1,950-2,050 m) species reached the e maximum,that is 30 species.The common species first increased and then decreased and finally got stabilized between neighboring altitudinal gradients.The seed density of P.schrenkiana forests soil seed bank presented single peak distribution pattern,the maximum density(1 813.8 ± 154.0 seeds/m2) appearing at the altitude of 2,000 m(1,950-2,050 m).P.schrenkiana seed density in the soil seed bank also presented single peak distribution pattern,the maximum density(190.0 ± 16.8 seeds/m2) appearing at the altitude of 1,800 m(1,750-1,850 m).【Conclusion】With the altitude rising,the number of species composition of P.schrenkiana forests soil seed bank shows a declining trend in the fluctuation as a whole.Both of the seed density in P.schrenkiana forests soil seed bank and P.schrenkiana seed density in the soil seed bank presented single peak distribution pattern with the altitude rising.However,they do not share synchronization on the vertical distribution of the altitude.