气候变化领域集成服务门户(CCPortal): Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests

CCPortal

DOI	10.1016/j.foreco.2019.02.017
	Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests
	Hendricks J.J.; Holland J.B.; Hubbartt J.S.
发表日期	2019
ISSN	0378-1127
起始页码	123
结束页码	133
卷号	438
英文摘要	Prescribed burning is one of the most commonly used management practices in pine (Pinus spp.) forests of the southeastern United States. There is concern, however, that burning may lead to excessive losses of nitrogen (N), thereby decreasing forest productivity. The N losses due to burning may be potentially countered via symbiotic N 2 -fixation by native and naturalized herbaceous legumes that may thrive in burned forests. However, the rates and controls of N input via legume N 2 -fixation in these ecosystems are poorly understood. The objectives of this study were to measure legume abundance, biomass, N 2 -fixation, substrate quality, and associated environmental controls in regularly burned loblolly pine (P. taeda) forests. The study sites were located in four management blocks at the Piedmont National Wildlife Refuge. This assessment revealed a total of 23 legume species in 9 genera. Legume abundance averaged 12.95 ± 2.30 individuals m −2 , and collectively Centrosema virginianum, Chamaecrista nictitans, Desmodium marilandicum, Galactia volubilis, and Lespedeza procumbens constituted 70.8% of the total legume abundance. Legumes comprised 17.1% of the understory aboveground biomass, and legume foliage, stem, and total (foliage + stem) biomass estimates averaged 15.38 ± 3.18, 20.88 ± 4.01, 36.26 ± 6.95 g m −2 , respectively. Legume foliar N concentration averaged 2.22 ± 0.06% (ranging from 1.42−2.83%), and all legume foliar N concentrations were significantly higher than the average foliar values for blackberry (Rubus spp., 1.10 ± 0.05%) and the aggregate of non-leguminous forbs (1.03 ± 0.08%) that grew concurrently with the legumes in the study sites. N 2 -fixation assessments, based on the differential between legume and non-N 2 -fixing reference plant foliar N concentrations, indicated that approximately 50% of legume N was derived from the atmosphere. Legume foliage tissues exhibited relatively high substrate quality indices such as high N concentrations, low lignin concentrations (average of 14.3 ± 1.9%), and correspondingly low lignin:N ratios (average of 6.7 ± 0.9) indicative of tissues that exhibit rapid mass loss and N mineralization rates during decomposition. Canopy openness was the environmental variable that was most strongly correlated with foliar N and areal biomass among the dominant legume species. The estimated N input of 0.14 g m −2 yr −1 via N 2 -fixation may compensate for N losses due to relatively low intensity and infrequent understory burns during a stand rotation. Additional studies are needed to more comprehensively assess legume N 2 -fixation inputs, associated environmental constraints, and practical field applications which may increase N input via symbiotic N 2 -fixation in regularly burned pine forest ecosystems. © 2019 Elsevier B.V.
英文关键词	15 N natural abundance; Lignin; Loblolly pine forest; N 2 -fixation; Native herbaceous legumes; Nitrogen; Piedmont ecoregion; Prescribed burning; Substrate quality
语种	英语
scopus关键词	Biomass; Ecosystems; Forestry; Histology; Lignin; Nitrogen; Plants (botany); Quality control; Tissue; Ecoregions; Loblolly pine forest; N2 fixation; Native herbaceous legumes; Natural abundance; Prescribed burning; Substrate quality; Nitrogen fixation; assessment method; biomineralization; coniferous forest; ecoregion; forest ecosystem; forest management; forestry production; habitat quality; herb; legume; native species; nitrogen; nitrogen cycle; nitrogen fixation; prescribed burning; substrate; Biomass; Ecosystems; Forestry; Histology; Nitrogen; Piedmont [United States]; United States; Centrosema virginianum; Chamaecrista nictitans; Desmodium marilandicum; Galactia volubilis; Lespedeza procumbens; Pinus taeda; Rubus
来源期刊	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156107
作者单位	Department of Biology, University of West Georgia, 1601 Maple Street, Carrollton, GA 30118, United States
推荐引用方式 GB/T 7714	Hendricks J.J.,Holland J.B.,Hubbartt J.S.. Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests[J],2019,438.
APA	Hendricks J.J.,Holland J.B.,&Hubbartt J.S..(2019).Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests.Forest Ecology and Management,438.
MLA	Hendricks J.J.,et al."Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests".Forest Ecology and Management 438(2019).