Nitrogen uptake pattern of herbaceous plants: coping strategies in altered neighbor species

• Published in: Biology and fertility of soils Vol. 53; no. 7; pp. 729 - 735
• Main Authors: Hong, Jiangtao, Ma, Xingxing, Zhang, Xiaoke, Wang, Xiaodan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2017; Springer Nature B.V
• Subjects: Absorption; Agriculture; ammonium nitrogen; Aridity; Biodiversity; Biomedical and Life Sciences; Capacity; Carex; China; Community ecology; Complementarity; coping strategies; Dominant species; Ecological effects; Ecosystems; Extreme environments; Flowers & plants; Glycine; Glycine (amino acid); herbaceous plants; Interspecific; Interspecific relationships; Leontopodium; Life Sciences; Mineral nutrients; Neighborhoods; Niches; nitrate nitrogen; Nitrogen; Nitrogen isotopes; Phenotypic plasticity; Plant communities; Plant diversity; Plant ecology; Plant species; Plastic properties; Plasticity; Resource partitioning; Resource utilization; Short Communication; Soil Science & Conservation; Species diversity; stable isotopes; Steppes; Stipa; Tracer techniques; Tracers; Uptake; China; Nitrogen forms; Niche complementarity; Nitrogen uptake; Neighbor removals; Species coexistence
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s00374-017-1230-0

The mechanisms for maintaining the species diversity of plant communities under conditions of resource limitation is an important subject in ecology. How interspecific relationships influence the pattern of nutrient absorption by coexisting species in N-limited ecosystems is still disputed. We investigated the effect of neighbor species on the uptake of inorganic and organic N by three common plant species using 15 N tracer techniques in a semi-arid alpine steppe on the northern Tibet. The results showed that the plant species varied in their capacity to absorb NO 3 − -N, NH 4 + -N, and glycine-N with or without neighbor species. Carex moorcroftii and Leontopodium nanum showed much more plasticity in resource utilization than Stipa purpurea when neighbor species were present. When C. moorcroftii and S. purpurea coexisted, they all increased their 15 N uptake for the NO 3 − -N ( C. moorcroftii 2.2-fold increase and S. purpurea 2.2-fold increase) and glycine-N treatments ( C. moorcroftii 2.9-fold increase and S. purpurea 3.4-fold increase), which indicated that neighborhood had a positive effect for N absorption between the two species. However, L. nanum was a less effective competitor for N utilization than the neighbor species across almost all treatments. The dominant species appeared to have an inhibitory effect on N absorption by the accompanying species in this alpine steppe environment. Thus, interspecific neighbor pairs may result in both a mutually beneficial cooperative relationship and a competitive relationship among neighbors in resource use patterns in extreme environments. Resource use plasticity in altered neighbor species may be due to phenotypic plasticity based on the conditions of the realized niche, offering a valuable insight into niche complementarity and providing a general and important mechanism for resource partitioning in an alpine area.