Carbon allocation, nodulation, and biological nitrogen fixation of black locust (Robinia pseudoacacia L.) under soil water limitation

Annals of Forest Research

Katja Boldt-Burisch¹  Dirk Freese¹  Maik Veste¹  Simone Fritsch¹  Dario Mantovani²  Laurie Anne Koning³ 

[1] Brandenburg University of Technology Cottbus-Senftenberg, Chair of Soil Protection and Recultivation, Konrad-Wachsmann-Allee 6, 03046 Cottbus, Germany;Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria, Via Nursina 2, 06049 - Spoleto;University of Rostock, Crop Health, Satower Straße 48, 18059 Rostock, Germany;

关键词: rhizobium, water use efficiency, carbon, nitrogen, natural 15nabundance, drought stress;   

DOI  :  10.15287/afr.2015.420

来源: DOAJ

【 摘 要 】

The pioneer tree black locust (Robinia pseudoacacia L.) is a drought-resistant tree and, in symbiosis with Rhizobium, able to fix dinitrogen from the atmosphere. It is, therefore, an interesting species for marginal lands where soil amelioration is sought in addition to economic gain. However, the interaction between soil water availability, carbon allocation and nitrogen fixation is important for a successful establishment of trees on marginal lands and has not yet been investigated for black locust. Twoyear-old trees were grown under various soil water conditions and drought cycles. The stable isotopic composition of C (δ 13C) and N (δ 15N) of the leaves was used to identify i) the effective drought condition of the treatments and ii) the portion N accrued from the atmosphere by the biological nitrogen fixation. Drought-stressed plants significantly reduced their total aboveground biomass production, which was linearly linked to tree transpiration. The shoot:root ratio values changed from 2.2 for the drought-stressed to 4.3 for the well-watered plants. Our investigation shows that drought stress increases the nodule biomass of black locust in order to maintain biological nitrogen fixation and to counteract the lower soil nitrogen availability. The biological nitrogen fixation of drought-stressed trees could be maintained at relatively higher values compared to the well-watered trees. The average leaf nitrogen content varied between 2.8% and 3.0% and was not influenced by the drought stress. Carbon fixation, carbon allocation, and biological nitrogen fixation are to some extent balanced at low irrigation and allow Robinia to cope with long-term water constraints. The combination of black locust’s ecophysiological and morphological plasticity make it interesting as a biomass source for bioenergy and timber production, even in nutrient-limited and drought-affected areas of Europe.

【 授权许可】

Unknown