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Substantial temperature rise is reported in the Himalayas, and the vulnerability of the region to climate change is well recognized. An apt adaptation strategy to cope with climate change calls for informed people's participation, which was rarely investigated in the western Himalayas. Having been better informed, people in developed areas adopt better actions against climate change that are well guided by their perception. In contrast, Rajouri in Jammu and Kashmir represents a relatively impoverished and climate change--vulnerable region. Therefore, we gauged people's perceptions and actions in this area from a household survey from 717 randomly selected individuals. Further, consistency of perception was compared with meteorological records on temperature, humidity, wind speed, rainfall, and aboveground biomass from 1983 to 2013. The findings revealed that temperature increased significantly while changes in rainfall, wind speed, and relative humidity were insignificant. Although people sensed a rise in temperature and deforestation correctly, most of them differ with respect to rainfall, wind speed, and humidity. They reported rising pollution and traffic but no change in crop productivity or crop varieties.Of the respondents, 91%considered climate change as a risk, 86.8%reported reactive actions to it, and 82.8% reported proactive actions. Locals from varied socioeconomic backgrounds are not much informed about climate change; hence, the reasonability of their responses and positive adaptation actions needs further research. To engage people in climate adaptation actions, we suggest disseminating precise scientific information about local climate through awareness programs and by engaging them in climate change activities through suitable organizations. [ABSTRACT FROM AUTHOR]

[Display omitted] Terrestrial species are predicted to migrate northward under global warming conditions, yet little is known about the direction and magnitude of change in microbial distribution patterns. In this continental-scale study with more than 1600 forest soil samples, we verify the existence of core microbiota and lump them into a manageable number of eco-clusters based on microbial habitat preferences. By projecting the abundance differences of eco-clusters between future and current climatic conditions, we observed the potential warming-driven migration of the core microbiota under warming, partially verified by a field warming experiment at Southwest China. Specifically, the species that favor low pH are potentially expanding and moving northward to medium-latitudes (25°–45°N), potentially implying that warm temperate forest would be under threat of soil acidification with warming. The eco-cluster of high-pH with high-annual mean temperature (AMT) experienced significant abundance increases at middle- (35°–45°N) to high-latitudes (> 45°N), especially under Representative Concentration Pathway (RCP) 8.5, likely resulting in northward expansion. Furthermore, the eco-cluster that favors low-soil organic carbon (SOC) was projected to increase under warming scenarios at low-latitudes (< 25°N), potentially an indicator of SOC storage accumulation in warmer areas. Meanwhile, at high-latitudes (> 45°N) the changes in relative abundance of this eco-cluster is inversely related with the temperature variation trends, suggesting microbes-mediated soil organic carbon changes are more responsive to temperature variation in colder areas. These results have vital implications for the migration direction of microbial communities and its potential ecological consequences in future warming scenarios. [ABSTRACT FROM AUTHOR]

The pattern of intense defoliation of rubber trees ( Hevea brasiliensis ) in Southwest China is assumed to mainly be attributable to drought stress. However, this has never been proven, and the pattern remains unclear. Our objectives were to reveal the driving factor and pattern of intense defoliation, and to explore the characteristics of sap flow density ( J s ) and relate them to climatic factors before, during and after the intense defoliation period. We continuously measured J s and related climatic factors in a rubber plantation in Southwest China from 2013 to 2016 and found that (1) the cold stress (<10 °C) was more relevant to intense defoliation than drought stress, and after encountering cold stress the rubber trees might enter dormancy for approximately 50 days during the defoliation period; (2) J s showed a self-regulating ability to respond to high air temperature ( T a ) and water vapor pressure deficit ( VPD ) with a time lag of approximately one hour during all periods except during the defoliation period; (3) the sensitivity of J s to T a weaken ( slope  = 0.14, r  = 0.17, P  > 0.05) during the defoliation period, but it rebounded back to a relative high level ( slope  = 1.44, r  = 0.55, P  < 0.01) during the refoliation period which was similar to that during the remaining periods; and (4) the relationship between J s and T a was generally positive, while both SWC 5 and SWC 100 exerted inhibitory effects on J s , and the interactive effects among T a , SWC 5 and SWC 100 on J s were significant during the refoliation period ( P  < 0.01). Based on these findings, we evaluated J s as a crucial physiological indicator of the processes underlying important phenological transition periods, and the cold stress rather than drought stress was likely the driving factor of the pattern of intense defoliation occurred in Southwest China rubber plantations. [ABSTRACT FROM AUTHOR]

Forest ecosystems play an increasingly important role in the global carbon cycle. However, knowledge on carbon exchanges, their spatio-temporal patterns, and the extent of the key controls that affect carbon fluxes is lacking. In this study, we employed 29-site-years of eddy covariance data to observe the state, spatio-temporal variations and climate sensitivity of carbon fluxes (gross primary productivity (GPP), ecosystem respiration (R eco ), and net ecosystem carbon exchange (NEE)) in four representative forest ecosystems in Yunnan. We found that 1) all four forest ecosystems were carbon sinks (the average NEE was − 3.40 tC ha − 1 yr − 1 ); 2) contrasting seasonality of the NEE among the ecosystems with a carbon sink mainly during the wet season in the Yuanjiang savanna ecosystem (YJ) but during the dry season in the Xishuangbanna tropical rainforest ecosystem (XSBN), besides an equivalent NEE uptake was observed during the wet/dry season in the Ailaoshan subtropical evergreen broad-leaved forest ecosystem (ALS) and Lijiang subalpine coniferous forest ecosystem (LJ); 3) as the GPP increased, the net ecosystem production (NEP) first increased and then decreased when the GPP > 17.5 tC ha − 1 yr − 1 ; 4) the precipitation determines the carbon sinks in the savanna ecosystem (e.g., YJ), while temperature did so in the tropical forest ecosystem (e.g., XSBN); 5) overall, under the circumstances of warming and decreased precipitation, the carbon sink might decrease in the YJ but maybe increase in the ALS and LJ, while future strength of the sink in the XSBN is somewhat uncertain. However, based on the redundancy analysis, the temperature and precipitation combined together explained 39.7%, 32.2%, 25.3%, and 29.6% of the variations in the NEE in the YJ, XSBN, ALS and LJ, respectively, which indicates that considerable changes in the NEE could not be explained by variations in the temperature and precipitation. Therefore, the effects of other factors (e.g., CO 2 concentration, N/P deposition, aerosol and other variables) on the NEE still require extensive research and need to be considered seriously in carbon-cycle-models. [ABSTRACT FROM AUTHOR]

Soil respiration, the second largest CO 2 flux in terrestrial ecosystems, involves the microbial respiration of litter from aboveground sources, belowground litter and root respiration, from rhizodeposition. In the subtropical forests of the Ailao Mountain, a chamber with automated CO 2 efflux was set up with two treatments: a control treatment with litterfall to measure the total soil respiration (R T) and a litter removal treatment to measure aboveground litterfall respiration (R L). This study aimed to examine the responses of R L to unexpected heavy snowfall events and soil temperature (ST), soil moisture (SM), rainfall (RF), total litterfall (TL), litter water content (LWC), nitrate nitrogen (NO 3 −-N), and ammonium nitrogen (NH 4 +-N). The period of the study was divided into two: before the heavy snowfall event (BS) and during and after the heavy snowfall event (AS). The rate of R L was slightly decreased in AS (1.18 ± 0.03 μmol CO 2 m−2 s−1) compared with that in BS (1.19 ± 0.02 μmol CO 2 m−2 s−1). The relationships between R L and ST, SM, RF, and LWC, respectively, were all statistically significant (p < 0.05) in both periods. However, the relationships between R L and TL and NH 4 +-N, respectively, were not statistically significant for either period. The relationship between R L and NO 3 −-N was statistically significant for AS but not for BS. The relationship between R L and RF was statistically significant from 2011 to 2018. The temperature dependence of soil respiration was higher in BS than in AS, and the effect of litter removal was 2.55 % and 2.32 % for AS and BS respectively. The results indicate that current global terrestrial models underestimate R L trends for the feedback of global climate change in subtropical forests. Aboveground litterfall respiration (R L) had strong connection with soil temperature, soil moisture, rainfall and litter water content for two periods but not for ammonium nitrogen (NH 4 +-N). Unexpected snowfall events took effects the connection between R L and total litterfall. Heavy snowfall events declined the relationship between R L and nitrate nitrogen (NO 3 −-N). [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Subtropical and tropical forest showed different temporal variations in carbon fluxes. [•] Seasonal variation in NEE of tropical forest was driven by ER. [•] Seasonal variation in NEE of subtropical forest was driven by both GPP and ER. [•] Annual rainfall drives interannual variation in subtropical or tropical forest. [ABSTRACT FROM AUTHOR]