N2-fixing tropical legume evolution: a contributor to enhanced weathering through the Cenozoic?

نویسندگان

  • Dimitar Z Epihov
  • Sarah A Batterman
  • Lars O Hedin
  • Jonathan R Leake
  • Lisa M Smith
  • David J Beerling
چکیده

Fossil and phylogenetic evidence indicates legume-rich modern tropical forests replaced Late Cretaceous palm-dominated tropical forests across four continents during the early Cenozoic (58-42 Ma). Tropical legume trees can transform ecosystems via their ability to fix dinitrogen (N2) and higher leaf N compared with non-legumes (35-65%), but it is unclear how their evolutionary rise contributed to silicate weathering, the long-term sink for atmospheric carbon dioxide (CO2). Here we hypothesize that the increasing abundance of N2-fixing legumes in tropical forests amplified silicate weathering rates by increased input of fixed nitrogen (N) to terrestrial ecosystems via interrelated mechanisms including increasing microbial respiration and soil acidification, and stimulating forest net primary productivity. We suggest the high CO2 early Cenozoic atmosphere further amplified legume weathering. Evolution of legumes with high weathering rates was probably driven by their high demand for phosphorus and micronutrients required for N2-fixation and nodule formation.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Legume Shrubs Are More Nitrogen-Homeostatic than Non-legume Shrubs

Legumes are characterized as keeping stable nutrient supply under nutrient-limited conditions. However, few studies examined the legumes' stoichiometric advantages over other plants across various taxa in natural ecosystems. We explored differences in nitrogen (N) and phosphorus (P) stoichiometry of different tissue types (leaf, stem, and root) between N2-fixing legume shrubs and non-N2-fixing ...

متن کامل

Legume Sanctions and the Evolution of Symbiotic Cooperation by Rhizobia.

The legume-rhizobium symbiosis is an ideal model for studying the factors that limit the evolution of microbial mutualists into parasites. Legumes are unable to consistently recognize parasitic rhizobia that, once established inside plant cells, use plant resources for their own reproduction rather than for N2 fixation. Evolution of parasitism in rhizobia, driven partly by competition among mul...

متن کامل

Globally distributed uncultivated oceanic N2-fixing cyanobacteria lack oxygenic photosystem II.

Biological nitrogen (N2) fixation is important in controlling biological productivity and carbon flux in the oceans. Unicellular N2-fixing cyanobacteria have only recently been discovered and are widely distributed in tropical and subtropical seas. Metagenomic analysis of flow cytometry-sorted cells shows that unicellular N2-fixing cyanobacteria in "group A" (UCYN-A) lack genes for the oxygen-e...

متن کامل

Genome Sequence of Bradyrhizobium stylosanthis Strain BR 446T, a Nitrogen-Fixing Symbiont of the Legume Pasture Stylosanthes guianensis

Bradyrhizobium stylosanthis BR 446(T) is a nitrogen-fixing symbiont of the tropical legume pasture Stylosanthes guianensis Its draft genome contains 8,801,717 bp and 8,239 coding sequences (CDSs). Several putative genes that might confer high competitiveness and saprophytic capacity under the stressful conditions of tropical soils were identified in the genome.

متن کامل

Nutrient acquisition, soil phosphorus partitioning and competition among trees in a lowland tropical rain forest.

We hypothesized that dinitrogen (N2 )- and non-N2 -fixing tropical trees would have distinct phosphorus (P) acquisition strategies allowing them to exploit different P sources, reducing competition. We measured root phosphatase activity and arbuscular mycorrhizal (AM) colonization among two N2 - and two non-N2 -fixing seedlings, and grew them alone and in competition with different inorganic an...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 284  شماره 

صفحات  -

تاریخ انتشار 2017