垫状点地梅对生长季土壤净氮矿化和酶活性的影响  

Effect of a Cushion Plant,Androsace tapete,on Soil Net Nitrogen Mineralization and Enzyme Activities during the Growing Season

作　　者：邢硕 何永涛[1,3] 牛犇 徐兴良[1] 宋茜[1,4] 王英凡 XING Shuo;HE Yongtao;NIU Ben;XU Xingliang;SONG Qian;WANG Yingfan(Lhasa Plateau Ecosystem Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100190,China;College of Geographical Sciences,Liaoning Normal University,Dalian,Liaoning 116029,China)

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室拉萨高原生态试验站,北京100101 [2]中国科学院大学,北京100049 [3]中国科学院大学资源与环境学院,北京100190 [4]辽宁师范大学,辽宁大连116029

出　　处：《Journal of Resources and Ecology》2024年第2期422-430,共9页资源与生态学报（英文版）

基　　金：The National Natural Science Foundation of China(31770477)。

摘　　要：垫状植物是高寒生态系统中一类独特的物种,具有厚实的多年生垫状体,可以改善局部微环境,从而对生长于其内部的其他物种起到保育作用,被称为高寒生态系统的工程师,其中对土壤养分有效性的改变是其保育作用的重要途径,但关于这一过程的研究目前还很少。本研究选择青藏高原广泛分布的垫状点地梅(Androsace tapete),在西藏当雄念青唐古拉山脉南坡4500 m和4800 m两个海拔设置样地,通过动态测定垫状点地梅覆盖下土壤和无垫状点地梅生长的对照草地土壤在生长季中的无机氮含量、净氮矿化速率以及土壤酶活性,对比分析垫状点地梅对土壤氮素有效性的影响。结果表明:(1)土壤中硝态氮和铵态氮含量在4500 m样地无显著差异,但在4800 m样地,垫状点地梅覆盖下土壤的硝态氮与无机氮含量在生长季中期有显著增加,其中硝态氮比对照草地增加了56%,无机氮则增加了74.5%;(2)垫状点地梅还改变了土壤中氮的矿化趋势和速率。在4500 m样地,垫状点地梅覆盖下土壤净氮矿化在生长季中期为负值(氮固定),速率为-0.11μg g^(-1)d^(-1),而对照草地土壤则为正值(氮矿化),速率为0.61μg g^(-1)d^(-1),二者差异显著;在生长季初期和末期二者均为正值,但差异未达到显著水平;在4800 m样地,垫状点地梅覆盖下的土壤在生长季初期的净氮矿化为正值,速率为0.07μg g^(-1)d^(-1),而对照草地土壤则为负值,速率为-1.17μg g^(-1)d^(-1),差异达到了显著水平;生长季中期二者均为负值,但垫状点地梅覆盖下土壤净氮矿化速率(-1.95μg g^(-1)d^(-1))显著低于对照草地土壤(-0.02μg g^(-1)d^(-1));在生长季末期二者也均为负值,且差异不显著。(3)垫状点地梅覆盖下土壤中的硝酸还原酶与亚硝酸还原酶活性显著提高。与对照草地土壤相比,4500 m样地垫状点地梅覆盖下土壤中的硝酸还原酶活性提高了9.1%,亚硝酸还原酶活性提高了1Cushion plants are one kind of unique specie in alpine ecosystems.They have a compact perennial cushion structure and play a role in facilitating the survival of other associated species by improving the local micro-environment.They are called“engineers”in the alpine ecosystem and their enhancement of soil nutrient availability is one of the ways of their engineering effect.In this study,Androsace tapete,a species of cushion plant widely distributed on the Qinghai-Tibet Plateau,was selected to investigate the dynamics of this process during the growing season at elevations of 4500 m and 4800 m on the southern slope of the Nyenchenthanglha mountains in Damxung.The effects of A.tapete on soil nutrient availability were analyzed by comparing the inorganic nitrogen content,net nitrogen mineralization rate and soil enzyme activities during the growing season in the soil under A.tapete and ambient grassland(CK).The results showed three important aspects of this system.(1)Soil nitrate nitrogen and ammonium nitrogen did not show significant differences at 4500 m,but the contents of nitrate nitrogen and inorganic nitrogen under the A.tapete soil significantly increased in the middle of the growing season at 4800 m,with nitrate nitrogen increasing by 56%and inorganic nitrogen increasing by 74.5%.(2)The trend and rate of soil nitrogen mineralization were both changed under A.tapete.In the 4500 m sample site,soil net nitrogen mineralization under A.tapete was negative(nitrogen immobilization)in the middle of the growing season,and the rate was-0.11μg g^(-1)d^(-1),while that of CK was positive(nitrogen mineralization)and the rate was 0.61μg g^(-1)d^(-1);and the difference between them was significant.However,both were positive in the early and late growing season,and the difference did not reach a significant level.In the 4800 m sample site,the soil net nitrogen mineralization under A.tapete was positive in the early part of the growing season,and the rate was 0.07μg g^(-1)d^(-1),while the mineralization for CK was neg

关 键 词：垫状植物 垫状点地梅 无机氮 净氮矿化 青藏高原 

分 类 号：S153.6[农业科学—土壤学] S154.2[农业科学—农业基础科学]