Sex‐specific strategies of nutrient resorption associated with leaf economics in Populus euphratica

Abstract

There are differences between sexes in physiological and functional traits and possibly in nutrient resorption, particularly in nutrient‐poor environments. However, little is known about the extent of nutrient resorption from fine stems and fine roots, and about how nutrient resorption is related to leaf economics in the males and females of dioecious trees. We investigated nutrient resorption of different organs and explored whether nutrient resorption is associated with nutrient conservation traits of leaves (e.g. leaf thickness, leaf mass per area, LMA) in Populus euphratica females and males in four natural forests along the Tarim River, China. Both female and male leaves had the highest N resorption efficiency (NRE), than stems and roots. We found sexual dimorphism in leaf nutrient resorption at Shaya, Luntai and Yuli forest sites, where P. euphratica males had higher leaf NRE than females, whereas females had a higher leaf P resorption efficiency (PRE). Moreover, the different nutrient resorption strategies were related to leaf economics. P. euphratica males possess a conservation strategy with a higher leaf thickness, LMA and leaf vein density, which positively correlated with leaf NRE, while females with higher leaf PRE resorbed disproportionately more P for the reproductive investment. Synthesis. Populus euphratica males possess a conservation strategy with higher leaf NRE, while females have higher leaf PRE for the reproductive investment. Due to spatial sexual segregation across environmental gradients, dioecious plants are especially vulnerable under future climate change. The differences in nutrient uptake and utilization strategies between females and males may result in a situation where one sex is more prone to future climate change than the other one. Such sex‐specific nutrient resorption strategies are associated with leaf economics. The present study deepens our understanding of the nutrient balance and adaptation strategies of plants under climate change.

Covariations and trade‐offs of phosphorus (P) acquisition strategies in dioecious Populus euphratica as affected by soil water availability

“…In addition, P. euphratica males tended to be more common at relatively drier and less fertile sites (Yu et al, 2022;Zhou et al, 2018).…”

“…Petzold et al (2013) found that P. euphratica showed a male biased sex ratio in Xinjiang, China. In addition, P. euphratica males tended to be more common at relatively drier and less fertile sites (Yu et al, 2022; Zhou et al, 2018). One way to assess potential sex ratio patterns and predict whether extreme sex ratio deviations are likely to occur under future climatic change context is to evaluate potential adaptive strategies associated with growth‐related secondary sex characters and their plasticity.…”

“…Females tend to bear greater reproductive costs than males due to the necessity to develop seeds and fruits (Juvany & Munne‐Bosch, 2015). In addition to the absolute costs of reproduction that may differ between the two sexes, the seed and fruit production tend to rely heavily on water and phosphorus (P), whereas pollen production requires large amounts of nitrogen (N) (Bürli et al, 2022; Lei et al, 2017; Yu et al, 2022).…”

Nutrient resorption responses of female and male Populus cathayana to drought and shade stress

“…Our results suggest that leaf economic traits are closely linked with nutrient uptake from senesced leaves in a dioecious plant. Plants can enhance nitrogen and phosphorus retention and increase nutrient uptake from senesced leaves to decrease their dependence on the external environment (Yu et al, 2022). Furthermore, the higher leaf thickness and LMA generally imply a longer leaf life span (Wright et al, 2004(Wright et al, , 2005, resulting in a longer nutrient residence time and photosynthetic assimilation time (Poorter et al, 2006).…”

Response to Midgley: the costs of reproduction cannot differ between the sexes

“…Several studies have indicated that sex-specific functional traits would be strongly affected by environmental factors (Guo et al 2022;Liu et al 2021cLiu et al , 2022aLiu et al , 2022bYu et al 2020Yu et al , 2022Zhang et al 2021). As discussed above, the observed annual growth rates are indeed equivalent in both sexes, which implies a potential compensation mechanism (Case and Ashman 2005).…”