Water Supply Changes N and P Conservation in a Perennial Grass Leymus chinensis

Abstract

Changes in precipitation can influence soil water and nutrient availability, and thus affect plant nutrient conservation strategies. Better understanding of how nutrient conservation changes with variations in water availability is crucial for predicting the potential influence of global climate change on plant nutrient-use strategy. Here, green-leaf nitrogen (N) and phosphorus (P) concentrations, N- and P-resorption proficiency (the terminal N and P concentration in senescent leaves, NRP and PRP, respectively), and N- and P-resorption efficiency (the proportional N and P withdrawn from senescent leaves prior to abscission, NRE and PRE, respectively) of Leymus chinensis (Trin.) Tzvel., a typical perennial grass species in northern China, were examined along a water supply gradient to explore how plant nutrient conservation responds to water change. Increasing water supply at low levels (< 9000 mL/year) increased NRP, PRP and PRE, but decreased green-leaf N concentration. It did not significantly affect green-leaf P concentration or NRE. By contrast, all N and P conservation indicators were not significantly influenced at high water supply levels (> 9000 mL/year). These results indicated that changes in water availability at low levels could affect leaf-level nutrient characteristics, especially for the species in semiarid ecosystems. Therefore, global changes in precipitation may pose effects on plant nutrient economy, and thus on nutrient cycling in the plant-soil systems.

Nitrogen enrichment alters nutrient resorption and exacerbates phosphorus limitation in the desert shrub Artemisia ordosica

“…Because the desert soil in our study contained only a small amount of organic matter (soil organic carbon content, 2.88 ± 0.18 g/kg; She et al., ), it is likely that water addition could not be enough to mineralize more available N from organic matter and thus could not enhance soil N availability (Wang et al., ). Alternatively, the simultaneous water addition with high natural precipitation in the present study may have led to soil N loss through leaching and denitrification (Huang, Yu, Li, Yuan, & Bartels, ; Srivastava, Singh, Tripathi, Singh, & Raghubanshi, ), resulting in no change in soil inorganic N availability. A recent study conducted in a temperate desert supports our findings, in which water addition had no impacts on leaf NRE of desert shrubs (Huang et al., ).…”

Impacts of drought on plant water relations and nitrogen nutrition in dryland perennial grasses

“…These differences may be related to higher plant transpiration rates and thus increased mass flow of N through the soil under well-watered conditions (Dunham and Nye 1973). In contrast, other authors have observed higher leaf N under drought conditions (Drenovsky et al 2012;Huang et al 2009;Wright et al 2001). This variability may be related to how plant growth and N allocation are influenced by water availability.…”

“…During the senescence process, mobile nutrients are retranslocated to storage tissues via the phloem, and water availability influences this process (Ruehr et al 2009). Although not as well studied as the influence of soil nutrient availability, other authors have observed decreased resorption in response to drought (Huang et al 2009;Marchin et al 2010;Westoby 2003 but see Sanz-Perez et al 2009). Second, the impacts of drought on resorption may depend on seasonal timing and duration of the drought.…”

Pathogen infection drives patterns of nutrient resorption in citrus plants

“…Our data show that season and the interaction of season and health status have significant effects on P concentration and resorption efficiency ( Table 2 ). After the early summer (the first sampling), the increases of temperature and rainfall can be beneficial for the infected C. reticulata plants to overcome the temporary disorder in the P transport and to return to a greater P resorption 33 34 35 . The P resorption process in the infected C. reticulata plants reflected the dynamic interaction between P and the plant-pathogen system.…”