Snow leopard (Panthera unica) is a felid which lives in the highly rugged areas of alpine regions in different mountain ranges of South and Central Asia. This solitary animal needs large spaces for its ranges but due to climate change and relatively faster rate of global warming in South Asian mountain ranges, its habitat is going to shrink and fragment by tree-line shifts and change in hydrology of the area. Vegetative modification of montane flora and competition with domestic goats will create its prey’s population to decline along with a chance of a direct conflict and competition with the common leopard. Common leopard being more adaptable, grouped, and larger in size can be a significant stressor for a smaller and solitary snow leopard. Habitat would shrink, and snow leopard can possibly move upslope or northward to central Asian ranges and their predicted migratory patterns are unknown.

<p>Freezing and thawing are common phenomena and potential sources of N2O emissions in ecosystems at high latitudes. Earlier it was hypothesized that the frozen soil layer might trap the underlying production of N2O and release this as the top layer is thawed. However, newer research has found other factors playing role in the de novo emissions such as fluctuating availability of organic matter, nitrates, and ammonia, microbial activity, and changing oxic conditions of the soil. But, the variation in the abundance of genes involved in the nitrogen cycle during these events is rarely explained thus, a generally accepted theory of the impact of freeze-thaw on N2O fluxes is still missing.<br />To further investigate the relationships between physical, chemical, and microbial parameters with N2O emissions, we conducted a two-week experiment of three thaw-freeze events in March 2022 using artificial heating with electrical cables installed in collars of greenhouse gas sampling chambers conducted in a drained Downy birch peatland forest. Gas and soil samples were obtained on three non-consecutive days from these collars. Soil temperature, soil water content (SWC), NH4-N, and NO3-N were measured in the soil. Also, the abundances of functional genes involved in the nitrification (bacterial, archaeal, and comammox (complete ammonia oxidation) amoA) and denitrification (nirS, nirK, nosZI, and nosZII) were known using qPCR.<br />Our results show that artificial heating induced the thawing of the frozen top layer of soil during our experiment. The increase in soil surface temperature positively correlated with the soil water content in the top layer (R=0.58, p<0.01). N2O emissions also increased with heating and correlated with SWC (R=0.38, p<0.01). Ammonia in soil decreased and was negatively associated with N2O emissions (R=−0.28, p<0.05), suggesting active nitrification as the amount of nitrates also increased during heating. The abundance of all functional genes significantly increased during the heating except for those responsible for the consumption of N2O (nosZ genes) during<br />denitrification. Although we found evidence of both active nitrification and denitrification, the multiple regressions between N2O emissions and the proportion of different functional genes suggest that the nirK-type denitrifiers dominated in the denitrification as well as in the overall production of the N2O (p<0.001). Meanwhile, the inactivation of N2O consumers (nosZ) at thawing temperatures resulted in the emission of N2O during the thawing events in the drained peatland’s nitrogen-rich soil.</p>

<p>Tropical peatlands are important sources or sinks of greenhouse gases CH<sub>4</sub> and N<sub>2</sub>O. However, comprehensive greenhouse gas flux assessments that incorporate different compartments of the ecosystem are scarce. The sensitivity of peatland greenhouse gas fluxes to hydrologic variability adds to the large uncertainty. Greenhouse gas dynamics of tropical Réunion Island peatland forests has not been previously studied. In addition, tree stems in tropical peatlands have been shown to emit CH<sub>4</sub> under waterlogged soil conditions, but further knowledge of these fluxes under different environmental and hydrological conditions is needed.</p> <p>We aimed to quantify the fluxes of CH<sub>4</sub> and N<sub>2</sub>O from tree stems and soil in high-altitude (1500-1600 m a.s.l.) cloud forest areas on peat soil on Réunion Island. Two study sites were examined during the dryer season – Plaine des Cafres and Forêt de Bébour. Stem fluxes were determined from tree heather <em>Erica reunionensis</em> (both study sites) and tree fern <em>Alsophila glaucifolia</em> (Plaine des Cafres) using static chamber systems mounted on tree stems, connected to trace gas analysers LI-COR LI-7810 (CH<sub>4</sub>) and LI-7820 (N<sub>2</sub>O), which measured gas concentration changes in chamber headspace during 10 minutes. Soil gases were sampled using static soil chamber systems at 20-minute intervals during one-hour sessions and analysed with gas chromatography (Shimadzu GC-2014). Soil environmental parameters were measured simultaneously with gas measurements at each site.</p> <p>Preliminary results show that stems of <em>Erica</em> emitted negligible amounts of CH<sub>4 </sub>(0.3 ± 2.71 (mean ± standard error) µg C m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup> at Plaine des Cafres and 0.58 ± 0.26 µg C m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup> at Forêt de Bébour) and small amounts of N<sub>2</sub>O (6.25 ± 2.37 µg N m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup> and 1.43 ± 4.65 µg N m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup>, respectively). Tree ferns took up CH<sub>4</sub> from the atmosphere (−21.45 ± 10.75 µg C m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup>) but had negligible N<sub>2</sub>O fluxes. Soils at both study sites were sinks of CH<sub>4</sub> (−12.41 ± 11.37 µg C m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup> and −21.5 ± 5.91 µg C m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup>) and small sources of N<sub>2</sub>O (1.06 ± 0.38 µg N m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup> and 0.37 ± 0.72 µg N m<sup>−</sup><sup>2</sup> h<sup>−</sup><sup>1</sup>).</p> <p>Our results indicate that stems of <em>Erica reunionensis</em> and <em>Alsophila glaucifolia</em> do not emit significant amounts of CH<sub>4</sub> and N<sub>2</sub>O to the atmosphere in the tropical peatlands of Réunion Island during the dryer season. Nevertheless, it is crucial to further monitor greenhouse gas emissions for a longer period to clarify spatio-temporal dynamics in different environmental conditions. In addition, the consumption of CH<sub>4</sub> by tree ferns shows that variability of  greenhouse gas fluxes from stems of different tree species needs further attention to determine the contribution of trees to total ecosystem greenhouse gas budgets for improved global assessments.</p>