Shrub modulates the stoichiometry of moss and soil in desert ecosystems, China

Abstract

Desert mosses, which are important stabilizers in desert ecosystems, are distributed patchily under and between shrubs. Mosses differ from vascular plants in the ways they take up nutrients. Clarifying their distribution with ecological stoichiometry may be useful in explaining their mechanisms of living in different microhabitats. In this study, Syntrichia caninervis, the dominant moss species of moss crusts in the Gurbantunggut Desert, China, was selected to examine the study of stoichiometric characteristics in three microhabitats (under living shrubs, under dead shrubs and in exposed ground). The stoichiometry and enzyme activity of rhizosphere soil were analyzed. The plant function in the above-ground and below-ground parts of S. caninervis is significantly different, so the stoichiometry of the above-ground and below-ground parts might also be different. Results showed that carbon (C), nitrogen (N) and phosphorus (P) contents in the below-ground parts of S. caninervis were significantly lower than those in the above-ground parts. The highest N and P contents of the two parts were found under living shrubs and the lowest under dead shrubs. The C contents of the two parts did not differ significantly among the three microhabitats. In contrast, the ratios of C:N and C:P in the below-ground parts were higher than those in the above-ground parts in all microhabitats, with significant differences in the microhabitats of exposed ground and under living shrubs. There was an increasing trend in soil organic carbon (SOC), soil total nitrogen (STN), soil available phosphorous (SAP), and C:P and N:P ratios from exposed ground to under living shrubs and to under dead shrubs. No significant differences were found in soil total phosphorous (STP) and soil available nitrogen (SAN), or in ratios of C:N and SAN:SAP. Higher soil urease (SUE) and soil nitrate reductase (SNR) activities were found in soil under dead shrubs, while higher soil sucrase (STC) and soil β-glucosidase (SBG) activities were respectively found in exposed ground and under living shrubs. Soil alkaline phosphatase (AKP) activity reached its lowest value under dead shrubs, and there was no significant difference between the microhabitats of exposed ground and under living shrubs. Results indicated that the photosynthesis-related C of S. caninervis remained stable under the three microhabitats while N and P were mediated by the microhabitats. The growth strategy of S. caninervis varied in different microhabitats because of the different energy cycles and nutrient balances. The changes of stoichiometry in soil were not mirrored in the moss. We conclude that microhabitat could change the growth strategy of moss and nutrients cycling of moss patches.

Spatial Scale-Depended Characteristic Of Moss and Soil C, N, P and K Stoichiometry and Their Relationships In A Temperate Desert of Central Asia

“…In the current study, no signi cant differences in moss C content were found in different spatial scales, except that moss C in below-ground parts. In addition, our previous studies found that moss C did not shift with changes of moss patch size and microhabitats (Li et al, 2019a;Li et al, 2019b). Thus, our previous and current results suggested that moss C was stable in different spatial scales from patch size (cm) to sampling site (10Km).…”

“…However, the ecological stoichiometry was rarely used in moss studies (Ball and Guevara, 2015;Ball and Virginia, 2014). Previous studies have found that moss stoichiometry is easily in uenced by environments (Ball and Guevara, 2015;Li et al, 2019a;Li et al, 2019b), and that moss growth showed consistent Potassium (K) or N-K colimitation in peatleads (Wang et al, 2016). Potassium is an important nutrient element which can enhance plant N retention (Chiwa et al, 2019;Osaki, 1995) and in uence the plant growth and photosynthetic rate in vascular plant (Cuzzuol et al, 2013).…”

Ecological stoichiometric characteristics of nitrogen and phosphorus in leaves, stems and roots of Haloxylon ammodendron in southern Gurbantunggut Desert and their relationship with soil factors

“…The N:P of H. ammodendronplants and organs in the study area was higher than 16, indicating thatH. ammodendron in the study area was more limited by P than N (Nie et al, 2022;Li et al, 2019). In this study, the N:P in leaves and stems of H. ammodendron was significantly higher than in roots, which may be resulted from the higher utilization efficiency of N and P in aboveground parts (Kerkhoff et al, 2006).…”

Leaf-root-soil N:P stoichiometry of ephemeral plants in a temperate desert in Central Asia

“…Thus, the increase in available N in crusted soils are indeed more than that in uncrusted soils (Tao et al 2020), leading to the high leaf N concentration of plants in the Gurbantunggut Desert to a large extent. In contrast, although soil available P can also be increased by BSCs to an extent (Li et al 2019), the impact is quite low mainly because of the harsh environment (e.g., dryhot, and alkaline soil) and low amount of phosphorussolubilizing bacteria. Furthermore, soil nutrient heterogeneity did not consistently influence leaf stoichiometry, as evidenced by their nonsignificant correlation coefficients (Table 3).…”