Nitrogen input by bamboos in neotropical forest: a new perspective

PeerJ

article

Maíra C.G. Padgurschi¹  Simone A. Vieira²  Edson J.F. Stefani¹  Gabriela B. Nardoto³  Carlos A. Joly¹ 

[1]Plant Biology Department, State University of Campinas

[2]Center for Environmental Studies and Research, State University of Campinas

[3]Department of Ecology, University of Brasilia

关键词: Merostachys neesii;    Atlantic forest;    Free-living biological nitrogen fixation;    N cycling;    Neotropical bamboo;   

DOI  :  10.7717/peerj.6024

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundNitrogen (N) is an important macronutrient that controls the productivity of ecosystems and biological nitrogen fixation (BNF) is a major source of N in terrestrial systems, particularly tropical forests. Bamboo dominates theses forests, but our knowledge regarding the role of bamboo in ecosystem functioning remains in its infancy. We investigated the importance of a native bamboo species to the N cycle of a Neotropical forest.MethodsWe selected 100 sample units (100 m2 each) in a pristine montane Atlantic Forest, in Brazil. We counted all the clumps and live culms of Merostachys neesii bamboo and calculated the specific and total leaf area, as well as litter production and respective N content. Potential N input was estimated based on available data on BNF rates for the same bamboo species, whose N input was then contextualized using information on N cycling components in the study area.ResultsWith 4,000 live culms ha−1, the native bamboo may contribute up to 11.7 kg N ha−1 during summer (January to March) and 19.6 kg N ha−1 in winter (July to September). When extrapolated for annual values, M. neesii could contribute more than 60 kg N ha−1y−1.DiscussionThe bamboo species’ contribution to N input may be due to its abundance (habitat availability for microbial colonization) and the composition of the free-living N fixer community on its leaves (demonstrated in previous studies). Although some N is lost during decomposition, this input could mitigate the N deficit in the Atlantic Forest studied by at least 27%. Our findings suggest that M. neesii closely regulates N input and may better explain the high diversity and carbon stocks in the area. This is the first time that a study has investigated BNF using free-living N fixers on the phyllosphere of bamboo.

【 授权许可】

CC BY