Publication
 

Patterns of nitrogen-fixing tree abundance in forests across Asia and America

  1.  Symbiotic nitrogen (N)‐fixing trees can provide large quantities of new N to ecosystems, but only if they are sufficiently abundant. The overall abundance and latitudinal abundance distributions of N‐fixing trees are well characterised in the Americas, but less well outside the Americas.
  2.  Here, we characterised the abundance of N‐fixing trees in a network of forest plots spanning five continents, ~5,000 tree species and ~4 million trees. The majority of the plots (86%) were in America or Asia. In addition, we examined whether the observed pattern of abundance of N‐fixing trees was correlated with mean annual temperature and precipitation.
  3.  Outside the tropics, N‐fixing trees were consistently rare in the forest plots we examined. Within the tropics, N‐fixing trees were abundant in American but not Asian forest plots (~7% versus ~1% of basal area and stems). This disparity was not explained by mean annual temperature or precipitation. Our finding of low N‐fixing tree abundance in the Asian tropics casts some doubt on recent high estimates of N fixation rates in this region, which do not account for disparities in N‐fixing tree abundance between the Asian and American tropics.
  4.  Synthesis. Inputs of nitrogen to forests depend on symbiotic nitrogen fixation, which is constrained by the abundance of N‐fixing trees. By analysing a large dataset of ~4 million trees, we found that N‐fixing trees were consistently rare in the Asian tropics as well as across higher latitudes in Asia, America and Europe. The rarity of N‐fixing trees in the Asian tropics compared with the American tropics might stem from lower intrinsic N limitation in Asian tropical forests, although direct support for any mechanism is lacking. The paucity of N‐fixing trees throughout Asian forests suggests that N inputs to the Asian tropics might be lower than previously thought.
Authors: 
Duncan N. L. Menge, Ryan A. Chisholm, Stuart J. Davies, Kamariah Abu Salim, David Allen, Mauricio Alvarez, Norm Bourg, Warren Y. Brockelman, Sarayudh Bunyavejchewin, Nathalie Butt, Min Cao, Wirong Chanthorn, Wei‐Chun Chao, Keith Clay, Richard Condit, Susan Cordell, João Batista da Silva, H. S. Dattaraja, Ana Cristina Segalin de Andrade, Alexandre A. de Oliveira, Jan den Ouden, Michael Drescher, Christine Fletcher, Christian P. Giardina, C. V. Savitri Gunatilleke, I. A. U. Nimal Gunatilleke, Billy C. H. Hau, Fangliang He, Robert Howe, Chang‐Fu Hsieh, Stephen P. Hubbell, Faith M. Inman‐Narahari, Patrick A. Jansen, Daniel J. Johnson, Lee Sing Kong, Kamil Král, Chen‐Chia Ku, Jiangshan Lai, Andrew J. Larson, Xiankun Li, Yide Li, Luxiang Lin, YiChing Lin, Shirong Liu, Shawn K. Y. Lum, James A. Lutz, Keping Ma, Yadvinder Malhi, Sean McMahon, William McShea, Xiangcheng Mi, Michael Morecroft, Jonathan A. Myers, Anuttara Nathalang, Vojtech Novotny, Perry Ong, David A. Orwig, Rebecca Ostertag, Geoffrey Parker, Richard P. Phillips, Kassim Abd. Rahman, Lawren Sack, Weiguo Sang, Guochun Shen, Ankur Shringi, Jessica Shue, Sheng‐Hsin Su, Raman Sukumar, I‐Fang Sun, H. S. Suresh, Sylvester Tan, Sean C. Thomas, Pagi S. Toko, Renato Valencia, Martha I. Vallejo, Alberto Vicentini, Tomáš Vrška, Bin Wang, Xihua Wang, George D. Weiblen, Amy Wolf, Han Xu, Sandra Yap, Li Zhu, and Tak Fung
Journal: 
Journal of Ecology
Year: 
2019
Pages: 
1-13
DOI: 
10.1111/1365-2745.13199
Site: 
Barro Colorado Island Bukit Timah Cocoli Donglingshan Fushan Gutianshan Haliburton Forest Harvard Forest Hong Kong Huai Kha Khaeng Khao Chong La Planada Lambir Laupahoehoe Lilly Dickey Woods Manaus Michigan Big Woods Mo Singto Mudumalai Nonggang Palamanui Palanan Pasoh San Lorenzo Sinharaja Smithsonian Conservation Biology Institute Smithsonian Environmental Research Center Speulderbos Tiantongshan Tyson Research Center University of California, Santa Cruz University of Maryland, Baltimore County Utah Wabikon Wanang Wind River Wytham Woods Xishuangbanna Yasuní Yosemite Zofin
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