摘要
通过6年的控制实验,研究刈割(留茬1cm、3cm、不刈割)和施肥(12.75g·m^(-2)尿素+3.06g·m^(-2)磷酸二铵、不施肥)对高寒草甸土壤和植物中N、P化学计量学特征的影响,探讨植物养分限制类型,为天然草原的管理利用、保护和恢复研究提供资料。结果显示:(1)刈割、施肥后土壤全N、全P含量及其N∶P比值无显著变化,但速效P含量显著增加;因速效养分被植物吸收,施肥与不施肥群落的土壤速效N、P含量无显著差异。(2)刈割和施肥引起群落叶层N、P含量增加,施肥导致叶层N∶P比降低。(3)刈割、施肥对豆科植物N、P含量及其N∶P比无显著影响,单独刈割增加了禾草的P含量和莎草的N含量,并降低了禾草的N∶P比值;单独施肥处理增加了禾草的P含量和莎草的N、P含量;豆科植物的N含量最高,莎草的P含量最低,禾草的N∶P比最低。(4)群落叶层、禾草及莎草的N含量与P含量呈显著正相关关系,N∶P比与N含量无显著相关性,而与P含量呈显著负相关关系;豆科植物的N、P含量呈显著负相关关系,N∶P比与N含量呈正相关关系,而与P含量呈显著负相关关系;说明群落和植物功能群营养状况主要受P限制。(5)群落地上生物量的相对生长率与群落叶层的N、P含量呈显著正相关关系,而与N∶P比呈显著负相关关系,符合生长速率假说,说明生长速率假说不仅适用于物种水平,在群落水平也成立。
We conducted a6-year field manipulative experiment in Kobresia humilis meadow of Qinghai-Tibet Plateau to study the effects of clipping(stubbled1cm,3cm and unclipped)and fertilizing(12.75g·m-2urea+3.06g·m-2diammonium phosphate,unfertilized)on the N,P eco-stoichiometric characters of soil and plants in alpine meadow.We look forward to exploring the type of plant nutrient limitation,and providing information for the management,protection and restoration of the natural grassland.The results showed that:(1)clipping and fertilizing had no significant effects on total N,P contents and N∶P ratio in soil.No significant change was found in soil available N content,while the soil available P content was raised significantly after clipping.Neither the total N,P content nor the available N,P content in soil changed significantly under fertilizing treatment as a result of those available nutrients added into the soil was quickly absorbed by plants rather than stored in soil nutrient pool.(2)Both clipping and fertilizing increased the N,P content of leaf layer in community,and fertilizing decreased the N∶P ratio.(3)Experimental treatments did not changed the N,P content and N∶P ratio of legumes,but clipping increased the P content of grasses and the N content of sedges,decreased the N∶P ratio of grasses independently.Fertilizing increased the P content of grasses and the N,P content of sedges independently.Thus legumes had the highest levels of N content,while lowest P content was found in sedges as well as N∶P ratio in grasses.(4)Whether the leaf layer of community,grasses or sedges,N content was positively related to P content,N∶P ratio had no significant correlation with N content and was negatively related to P contents.For legumes,there was a negative correlation between N and P content,and N∶P ratio positively related to N content and negatively related to P contents.This suggested that the nutritional status of community and plant species were more restricted by P content.(5)The relative growth rate of c
作者
张璐璐
李艳
王孝安
朱志红
李英年
ZHANG Lulu;LI Yan;WANG Xiaoan;ZHU Zhihong;LI Yingnian(College of Life Sciences, Shaanxi Normal University, Xi an 710062, China;Northwest Institute of Plateau Biology, Chinese Academy of Science, Xining 810008, China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2017年第11期2256-2264,共9页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31570425)
陕西师范大学研究生培养创新基金(2012CXS050)
关键词
生态化学计量特征
刈割
施肥
生长速率假说
高寒草甸
ecological stoichiometric characters
clipping
fertilizing
growth rate hypothesis
alpine meadow
