Climate change has become a global concern for scientists as it is affecting almost every ecosystem. Larix gmelinii and Betula platyphylla are native and dominant forest species in the Daxing'anling Mountains of Inner Mongolia, playing a major role in carbon sequestration of this region. is study was carried out to assess the effect of climate variables including precipitation and temperature on the biomass of Larix gmelinii and Betula platyphylla forests. For this purpose, we used the climate-sensitive stem biomass allometric model for both species separately to find out accurate stem biomass along with climatic factors from 1950 to 2016. A total of 66 random plots were taken to attain the data from this study area. Larix gmelinii and Betula platyphylla stem biomass have a strong correlation with annual precipitation (R 2 = 0.86, R 2 = 0.71, R 2 = 0.79, and R 2 = 0.59) and maximum temperature (R 2 = 0.76, R 2 = 0.64, R 2 = 0.67, and R 2 = 0.52). However, annual minimum temperature (R 2 = 0.58, R 2 = 0.43, R 2 = 0.55, and R 2 = 0.46) and annual mean temperature (R 2 = 0.40, R 2 = 0.22, R 2 = 0.36, and R 2 = 0.19) have a relatively negative impact on tree biomass. erefore, we suggest that both species have a very strong adaptive nature with climatic variation and hence can survive under drought and high-temperature stress climatic conditions.

Hyphae of arbuscular mycorrhizal fungi (AMF) in soil often form complex mycorrhizal networks among roots of same or different plant species for transfer of nutrients from one plant to another. However, the effect of soil nitrogen (N) availability on nutrient transfer between different plant species via common mycorrhizal networks (CMNs) has not been experimentally examined. In order to quantify CMN-mediated nutrient transfer between Leymus chinensis (LC) and Cleistogene squarrosa (CS), two systems, i.e., the CS-LC system (CS and LC were donor and recipient, respectively) and the LC-CS system (LC and CS were donor and recipient, respectively) were established. Stable isotopic 15N was applied to track N transfer between heterospecific seedlings connected by CMNs under three levels of soil N additions: no N addition control (N0), N addition with 7 mg kg -1 (N1) and N addition with 14 mg kg -1 (N2). In the CS-LC system, the highest rate of AMF colonization and hyphal length density (HLD) were found at N1. In contrast, maximum AMF colonization rate and HLD were recorded at N2 in LC-CS system. Consequently, plant biomass was significantly higher under N1 and N2 levels in CS-LC and LC-CS systems, respectively. Moreover, in CS-LC system, 15N transfer rate ranged from 16% to 61%, with maximum transfer rate at N1. For LC-CS system, 15N transfer rate was much lower, with the maximum occurring at N0. These findings suggest that CMNs could potentially regulate N-transfer from a donor to recipient plant depending upon the strength of individual plant carbon sink.

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