Water and nutrient relations of mistletoes at the drought limit of their hosting evergreen oaks in the semiarid upper Ya
- PDF / 829,894 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 59 Downloads / 145 Views
ORIGINAL ARTICLE
Water and nutrient relations of mistletoes at the drought limit of their hosting evergreen oaks in the semiarid upper Yangtze region, SW China Xiao‑Fang He1,2 · Song‑Wei Wang3 · Christian Körner3 · Yang Yang1 Received: 31 March 2020 / Accepted: 18 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Does mistletoe infestation influence the position of the dry range limit of oaks? We explored this question and our results contrast most earlier findings on host-mistletoe interaction. The study was located in the SE Himalayas in an environment with 200–360 mm annual precipitation falling mainly during the short monsoon season (hardly any rain during 9–10 month). The hemi-parasite species (HPs) Loranthus delavayi and Taxillus thibetensis are growing on Quercus pannosa s.l. at its drought-driven range limit. HPs mostly exhibited lower shoot water potentials than their hosts during both, the dry and the wet season. During the dry season, leaf conductance (gl) of the HPs was very low (100–200 mmol m−2 s−1) and mostly lower than in their host. During the wet season, both HPs and oaks reached high gl (up to c. 500 mmol m−2 s−1) with higher in HP or no clear differentiation. Leaf δ13C in HPs was lower than in the host, suggesting a small limitation of CO2 uptake by gl. Both HPs had higher foliage potassium (K) and phosphorus (P) and similar nitrogen (N) content than the host. Thus, counter to abundant literature, HPs consumed extra water (and dissolved nutrients) mainly during the wet season, not adding extra stress to their host trees under extreme drought. Both host trees and mistletoes track the monsoon regime, with peak activity confined to the brief moist period. Under these semi-arid conditions, mistletoes thus, do not seem to affect the drought-driven range limit of these oaks. Keywords Quercus pannosa · Loranthus delavayi · Taxillus thibetensis · Hemiparasite · Monsoon climate · Himalaya
Introduction
Communicated by Arthur Gessler. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00468-020-02039-x) contains supplementary material, which is available to authorized users. * Christian Körner [email protected] * Yang Yang [email protected] 1
Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
2
University of Chinese Academy of Sciences, Beijing, China
3
Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
Mistletoes are hemi-parasite (HP) angiosperms that rely entirely on the water and nutrient resources of their hosts, extracted directly from the host’s xylem by a haustorium (Scalon and Wright 2015). The majority of mistletoes (> 98%) belong to the family of Loranthaceae and Viscaceae and are widespread in diverse habitats in all continents, except Antarctica (Watson 2001). As a characteristic of mistletoes, greater leaf conductance and thus, higher rates of transpi
Data Loading...
