干旱区生态环境知识资源中心(Arid): How encroaching shrubs and nutrients affect N-2-fixation in the Chihuahuan desert

Arid

DOI	10.1007/s11104-021-05072-y
	How encroaching shrubs and nutrients affect N-2-fixation in the Chihuahuan desert
	Baldarelli, Lauren M.; Collins, Scott L.; Ward, David
通讯作者	Baldarelli, LM (corresponding author), Kent State Univ, Dept Biol Sci, Kent, OH 44242 USA.
来源期刊	PLANT AND SOIL
ISSN	0032-079X
EISSN	1573-5036
出版年	2021
卷号	466 期号:1-2 页码:545-556
英文摘要	Background and aims Organisms that are capable of nitrogen (N) fixation, such as some species of cyanobacteria in biological soil crusts (biocrusts), can be ecologically important especially in low-nutrient dryland ecosystems. In addition, woody plant encroachment is occurring in drylands globally, including many species of N-2-fixing shrubs and trees. We determined the effects of nutrient deposition and shrub encroachment by Larrea tridentata on N-2-fixation rates of biocrusts and compared these rates to another encroaching shrub, the N-2-fixer Prosopis glandulosa in the northern Chihuahuan Desert. Methods We used both the acetylene reduction assay (ARA) and the N-15 natural abundance techniques to determine N-2-fixation rates of biocrusts. We also assessed the effects of nutrient additions on biocrust N-2-fixation rates using a long-term N addition experiment started in 2008 that is part of the Nutrient Network (NutNet). Results There was no correlation between the ARA and delta N-15 methods. We found that P. glandulosa likely fixes more N (at least during the spring) than biocrusts based on delta N-15 content in roots. There was no significant difference in delta N-15 between P. glandulosa and our reference plant, L. tridentata. delta N-15 declined in N-fertilized plots presumably because biological nitrogen fixation (BNF) is costly or because added N has negative effects on microbial communities. Conclusions Biocrusts fixed less nitrogen than N-2-fixing legume shrubs during this sampling period. Nonetheless, biocrusts are still a significant contributor to N-2-fixation in these nutrient-poor drylands based on the large proportion of soil surface area occupied by these organisms.
英文关键词	Biological N-2 fixation N-15 natural abundance Biological soil crusts Shrub encroachment Nutrient additions Desert grassland
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000673394100001
WOS关键词	ATMOSPHERIC NITROGEN DEPOSITION ; BIOLOGICAL SOIL CRUSTS ; MICROBIAL COMMUNITIES ; FIXATION ; FERTILIZATION ; GRASS ; RESPIRATION ; REDUCTION ; FERTILITY ; SAVANNA
WOS类目	Agronomy ; Plant Sciences ; Soil Science
WOS研究方向	Agriculture ; Plant Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/364327
作者单位	[Baldarelli, Lauren M.; Ward, David] Kent State Univ, Dept Biol Sci, Kent, OH 44242 USA; [Collins, Scott L.] Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA
推荐引用方式 GB/T 7714	Baldarelli, Lauren M.,Collins, Scott L.,Ward, David. How encroaching shrubs and nutrients affect N-2-fixation in the Chihuahuan desert[J],2021,466(1-2):545-556.
APA	Baldarelli, Lauren M.,Collins, Scott L.,&Ward, David.(2021).How encroaching shrubs and nutrients affect N-2-fixation in the Chihuahuan desert.PLANT AND SOIL,466(1-2),545-556.
MLA	Baldarelli, Lauren M.,et al."How encroaching shrubs and nutrients affect N-2-fixation in the Chihuahuan desert".PLANT AND SOIL 466.1-2(2021):545-556.