中亚温带沙漠苔藓C、N、P、K化学计量特征与土壤养分和环境的关系

Moss C,N,P and K stoichiometry and their relationships are related to soil nutrients and environment in a temperate desert of central Asia

前期研究发现,荒漠区苔藓的化学计量特性受苔藓斑块大小、灌木和微环境的影响。研究苔藓在不同空间分布区的化学计量特性,对理解苔藓的生长和适应策略具有重要意义。本研究选取古尔班通古特沙漠生物结皮中的优势苔藓(齿肋赤藓,Syntrichia caninervis)和苔藓斑块下的土壤,测定了不同沙丘和采样区苔藓植物和土壤的化学计量特征与计量比。研究结果表明,除苔藓C含量,苔藓化学计量特征和土壤有效养分在沙漠不同区域显著不同。苔藓植物地上与地下部分N、P、K元素的异速生长指数分别为0.251、0.389、0.442。苔藓地上部分和地下部分的N、P异速生长指数分别为0.71和0.84。苔藓的化学计量特征在地上和地下部分分布不均。此外,苔藓N、P、K元素受年均降水量、经度和土壤养分的影响。苔藓植物的养分含量受空间分布、年均温度、年均降水量和土壤养分的影响,而苔藓的生长受N限制。本研究提供了不同空间尺度下苔藓的C、N、P、K的化学计量特征,并探讨了它们与环境变量的关系,有助于了解沙漠中N、P、K的营养模式和利用策略,以及它们对全球气候变化的潜在响应。

Previous studies showed that moss stoichiometric characteristics were influenced by moss patch size,shrubs and the environment in the desert.The study of moss stoichiometry in different spatial distribution areas is crucial for an understanding of growth and adaptation strategy of the mosses.In this study,the dominant moss(Syntrichia caninervis)of biological soil crusts and soil under the moss patches in the Gurbantunggut Desert were selected to determine their stoichiometry in different dunes and sites.Moss stoichiometry and soil available nutrients were significantly influenced by different distribution areas except for moss C.The Naboveground vs.Nbelowground'Paboveground vs.Pbelowground and Kaboveground vs.Kbelowground scaling exponents of moss were 0.251,0.389 and 0.442,respectively.The N vs.P scaling exponents were 0.71,0.84 in above-and below-ground parts of moss.Moss stoichiometry was disproportionately distributed in the above-ground and below-ground parts.Moreover,moss N,P and K elements were influenced by mean annual precipitation(MAP),longitude and soil nutrients.The nutrients of moss were affected by spatial distribution,mean annual temperature(MAT),MAP and soil nutrients.The growth of moss was limited by N element in the temperate desert.This study provides the stoichiometric characteristics of C,N,P and K of moss at different spatial scales and explores their relationships with environmental variables,which can help understand nutrient patterns and utilization strategy of N,P and K,and their potential responses to global climate changes in desert.