Published December 23, 2020 | Version v1
Dataset Open

Nitrogen economy of alpine plants on the north Tibetan Plateau: nitrogen conservation by resorption rather than open sources through biological symbiotic fixation

Creators

  • 1. Chinese Academy of Sciences

Description

Nitrogen (N) is one of the most important factors limiting plant productivity, and N fixation by legume species is an important source of N input into ecosystems. Meanwhile, N resorption from senescent plant tissues conserves nutrients taken up in the current season, which may alleviate ecosystem N limitation. N fixation was assessed by the 15N dilution technique in four types of alpine grasslands along the precipitation and soil nutrient gradients. The N resorption efficiency (NRE) was also measured in these alpine grasslands. The aboveground biomass in the alpine meadow was 4–6 times higher than in the alpine meadow-steppe, alpine steppe, and alpine desert-steppe. However, the proportion of legume species to community biomass in the alpine steppe and the alpine desert steppe was significantly higher than the proportion in the alpine meadow. N fixation by the legume plants in the alpine meadow was 0.236 g N m-2, which was significantly higher than N fixation in other alpine grasslands (0.041 to 0.089 g N m-2). The NRE in the alpine meadows was lower than in the other three alpine grasslands. Both the aboveground biomass and N fixation of the legume plants showed decreasing trends with the decline of precipitation and soil N gradients from east to west, while the NRE of alpine plants showed increasing trends along the gradients, which indicates that alpine plants enhance the NRE to adapt to the increasing droughts and nutrient-poor environments. The opposite trends of N fixation and NRE along the precipitation and soil nutrient gradients indicate that alpine plants adapt to precipitation and soil nutrient limitation by promoting NRE (conservative nutrient use by alpine plants) rather than biological N fixation (open sources by legume plants) on the north Tibetan Plateau.

Notes

Funding provided by: National Natural Science Foundation of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809
Award Number: 41703079 and 31870406,31870406

Files

Files (19.6 kB)

Name Size Download all
md5:ba30df201f8a3d7ea31321a32a0e288e
19.6 kB Download

Additional details

Related works

Is cited by
10.1002/ece3.6038 (DOI)