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Global maps of soil temperature
Abstract
Research in environmental science relies heavily on global climatic grids derived from estimates of air temperature at around 2 meter above ground1-3. These climatic grids however fail to reflect conditions near and below the soil surface, where critical ecosystem functions such as soil carbon storage are controlled and most biodiversity resides4-8. By using soil temperature time series from over 8500 locations across all of the world’s terrestrial biomes4, we derived global maps of soil temperature-related variables at 1 km resolution for the 0–5 and 5–15 cm depth horizons. Based on these maps, we show that mean annual soil temperature differs markedly from the corresponding 2 m gridded air temperature, by up to 10°C, with substantial variation across biomes and seasons. Soils in cold and/or dry biomes are annually substantially warmer (3.6°C ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are slightly cooler (0.7 ± 2.3°C). As a result, annual soil temperature varies less (by 17%) across the globe than air temperature. The effect of macroclimatic conditions on the difference between soil and air temperature highlights the importance of considering that macroclimate warming may not result in the same level of soil temperature warming. Similarly, changes in precipitation could alter the relationship between soil and air temperature, with implications for soil-atmosphere feedbacks9. Our results underpin that the impacts of climate and climate change on biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments.
... These Collembola are typical euedaphic species: no pigmentation, without eyes, and reduced or lacking furca (Hopkin, 1997). Table 1 shows each species' approximate site of collection, the annual mean soil temperature, and the maximum soil temperature of the warmest month of the collection site (Lembrechts et al., 2021). Founder populations for mass cultures were collected by Tullgren extraction of soil cores, where specimens were collected in beakers with a floor of moist plaster of Paris. ...
... The estimated soil temperatures at the different collection sites (0-5 cm depth) from 1979 to 2013 were extracted from Lembrechts et al. (2021). The relationship between UTL 60 and the max soil temperature of the warmest month at the collection site (Table 1) was analyzed using Pearson correlation. ...
... Table 1 Origin and time of collection of the six Collembola species investigated. Key thermal conditions of their site of collection are indicated (data from Lembrechts et al., 2021). ...
Studies show that tropical and mid-latitude terrestrial ectotherms are more vulnerable to global warming than species from high latitudes. However, thermal tolerance studies from these regions still lack soil invertebrates. In the present study, we investigated six euedaphic species of Collembola (of the genera Onychiurus and Protaphorura) sampled across latitudes ranging from 31° N to 64°N and determined their upper thermal limit (UTL) by static assays. In another experiment, we submitted springtails to high temperatures for exposure times causing 5%–30% mortality within each species. Survivors from this series of increasing heat injuries were used to determine the time-to-first-oviposition, and the number of eggs produced following heat exposure. Two hypotheses are tested in this study: 1) heat tolerance of species correlates positively with the environmental temperature of their habitat; 2) the most heat-tolerant species require less time to regain reproduction and produce more eggs than the least heat-tolerant species. Results showed that the UTL positively correlates to the soil temperature of the sampling site. The sequence of UTL60 (the temperature causing 50% mortality after 60 minutes of exposure) from highest to least was O. yodai > P. fimata > P. armata ≈ P. tricampata > P. macfadyeni > P. pseudovanderdrifti. Heat stress inflicted on springtails can delay reproduction in all species, and two species showed reduced egg production rate after heat exposure. For heat stress causing up to 30% mortality, the most heat-tolerant species did not have advantages over the least heat-tolerant species for what concerns the recovery of reproduction. The relation between UTL and recovery from heat stress is not linear. Our study provides evidence for a potential long-term effect of high temperature exposure on euedaphic species of Collembola and highlights the need for further studies on the effects of global warming on soil-living organisms.
... landscapes, including the Himalaya, change significantly over short distances. The distribution of a species is greatly influenced by near-surface temperature and precipitation (Lembrechts et al., 2022). However, due to the inaccessibility of future climatic data, we conducted the current study primarily using aerial climatic data. ...
In the current era of the anthropocene, climate change is one of the main determinants of species redistribution and biodiversity loss. Worryingly, the situation is alarming for endemic and medicinally important plant species with a narrow distributional range. Therefore, it is pivotal to inspect the influence of accelerated climate change on medicinally important threatened and endemic plant species. Using an ensemble approach, the current study aims at modelling the present distribution and predicting the future potential distribution coupled with the threat assessment of Swertia petiolata—a medicinally important endemic plant species in the Himalayan biodiversity hotspot. Our study revealed that under current climatic scenarios, the suitable habitats for the species occur across the western Himalayan region which includes the north-western Indian states (Jammu and Kashmir, Himachal Pradesh, and southern Uttarakhand), northern Pakistan, and north-western Nepal. Also, temperature seasonality (BIO4) and precipitation seasonality (BIO15) are the most significant bioclimatic variables determining the distribution of S. petiolata. Furthermore, the study projected a reduction in the suitable habitats for the species under future changing climatic scenarios with a reduction ranging from − 40.298% under RCP4.5 2050 to − 83.421% under RCP8.5 2070. Most of the habitat reduction will occur in the western Himalayan region. In contrast, some of the currently unsuitable Himalayan regions like northern Uttarakhand will show increasing suitability under climate change scenarios. The current study also revealed that S. petiolata is classified as Near Threatened (NT) following the IUCN criterion B. Hopefully, the present study will provide a robust tool for predicting the cultivation hotspots and devising scientifically effective conservation strategies for this medicinally important plant species in the Himalaya and similar environments elsewhere in the world.
... The current predictive distribution modelling study was conducted with the finer resolution of climatic data currently available (i.e., 30 arc sec-approx. 1 km at the equator) considering the fact that the climatic conditions of the Himalaya, vary significantly with shortest distances because of the topographically diverse habitats. Secondly, the near-surface climate is as essential as the aerial climatic factors in determining a species' range 108,109 . However, due to the non-availability of the former for future climatic scenarios, the current study relied heavily on aerial climatic data. ...
In the era of anthropocene, global warming tends to alter the distribution range of the plant species. Highly fragile to such changes are the species that are endemic, inhabit higher elevations and show narrow distribution ranges. Predicting and plotting the appropriate suitable habitats and keeping knowledge of how climate change will affect future distribution become imperative for designing effective conservation strategies. In the current study we have used BIOMOD ensemble forecasting to study the current and predict the future potential distribution of Dactylorhiza hatagirea and Rheum webbianum and describe their niche dynamics in Himalayan biodiversity hotspots under climate change scenarios using ecospat R package. Results reveal sufficient internal evaluation metrics with area under curve (AUC) and true skill statistic (TSS) values greater than 0.8 i.e. 0.93 and 0.98 and 0.82 and 0.90 for D. hatageria and R. webbianum respectively, which signifies robustness of the model. Among different bioclimatic variables, bio_1, bio_3, bio_8, bio_14 and bio_15 were the most influential, showing greater impact on the potential distribution of these plant species. Range change analysis showed that both the studied species will show significant contraction of their suitable habitats under future climatic scenarios. Representative Concentration Pathway (RCP) 8.5 for the year 2070, indicate that the suitable habitats could be reduced by about 51.41% and 70.57% for D. hatagirea and R. webbianum respectively. The results of the niche comparisons between the current and future climatic scenarios showed moderate level of niche overlap for all the pairs with D. hatageria showing 61% overlap for current vs. RCP4.5 2050 and R. webbianum reflects 68% overlap for current vs. RCP4.5 2050. Furthermore, the PCA analysis revealed that climatic conditions for both the species vary significantly between current and future scenarios. The similarity and equivalence test showed that the niche between present and future climate change scenarios is comparable but not identical. From the current study we concluded that the influence of climate change on the habitat distribution of these plant species in the Himalayan biodiversity hotspots can be considered very severe. Drastic reduction in overall habitat suitability poses a high risk of species extinction and thereby threatens to alter the functions and services of these fragile ecosystems. Present results can be used by conservationists for mitigating the biodiversity decline and exploring undocumented populations on one hand and by policymakers in implementing the policy of conservation of species by launching species recovery programmes in future on the other. The outcomes of this study can contribute substantially to understand the consequences of climate change in the Himalayan biodiversity hotspots.
... 1 km at the equator), however the climatic conditions of the mountainous landscapes including the Himalaya change considerably with shortest distances including elevation. Second, along with the aerial climatic conditions, the near surface climate is equally important in governing the distribution of a species (Lembrechts et al., 2020(Lembrechts et al., , 2021. However, the present study was performed primarily using the aerial climatic data due to the non-availability of the latter for future climatic scenarios. ...
In an era of climate change, identifying suitable habitats for ecosystem restoration is critical for conservation of globally threatened biodiversity. Here, we integrate the insights gained from ensemble modelling with the community field data on threatened Himalayan Trillium (Trillium govanianum) to identify the suitable sites for its habitat restoration. We used ensemble modelling to map the current potential distribution and predict the future suitable habitats for the species under future climate change scenarios. The predictive accuracy of the ensemble model was fairly good; and the most influential variables governing the distribution of Himalayan Trillium were precipitation of the driest month followed by mean diurnal range. The current potential suitable habitats for this species are mostly located in western parts of the Himalaya; however, a range shift from western to eastern Himalaya is predicted under future climate change scenarios. Further, the analysis of community data revealed that Himalayan Trillium is positively associated with two tree species (Abies pindrow and Taxus wallichiana) forming forest top-story, four understory shrubs (Viburnum grandiflorum, Parrotiopsis jacquemontiana, Skimmia laureola and Rhododendron campanulatum) and one herbaceous species (Podophyllum hexandrum). In particular, the shrubs serve as micro-refuges by facilitating the suitable growth and protect the species from unsustainable extraction and livestock grazing. Our findings highlight a two-pronged strategy for habitat restoration of Himalayan Trillium: (i) identification of suitable habitats using ensemble modelling at the pan-Himalayan scale, (ii) and its integration with the community information at local scale. Such an integrated approach offers a nature-based solution in guiding the climate change-integrated restoration programs in the Himalaya, and elsewhere in the world.
... While stand age is the most obvious, it does not appear to be tightly linked to soil respiration [39], and our research corroborates this. Forest stature can also affect forest soil microclimate; intact forests show a reduced temperature above the canopy [111,112] and current studies are evaluating the impact of vegetation structural properties on soil temperature [113]. In addition, there is evidence of a positive trend between forest development and efficiency in the enhancement of soil C storage, most likely related to the presence of microbial communities and plant roots more efficient in SOC storage [114]. ...
On the mountains, along an elevation gradient, we generally observe an ample variation in temperature, with the associated difference in vegetation structure and composition and soil properties. With the aim of quantifying the relative importance of temperature, vegetation and edaphic properties on soil respiration (SR), we investigated changes in SR along an elevation gradient (404 to 2101 m a.s.l) in the southern slopes of the Alps in Northern Italy. We also analysed soil physicochemical properties, including soil organic carbon (SOC) and nitrogen (N) stocks, fine root C and N, litter C and N, soil bulk densities and soil pH at five forest sites, and also stand structural properties, including vegetation height, age and basal area. Our results indicated that SR rates increased with temperature in all sites, and 55–76% of SR variability was explained by temperature. Annual cumulative SR, ranging between 0.65–1.40 kg C m⁻² yr⁻¹, decreased along the elevation gradient, while temperature sensitivity (Q10) of SR increased with elevation. However, a high SR rate (1.27 kg C m⁻² yr⁻¹) and low Q10 were recorded in the mature conifer forest stand at 1731 m a.s.l., characterized by an uneven-aged structure and high dominant tree height, resulting in a nonlinear relationship between elevation and temperature. Reference SR at 10°C (SRref) was unrelated to elevation, but was related to tree height. A significant negative linear relationship was found between bulk density and elevation. Conversely, SOC, root C and N stock, pH, and litter mass were best fitted by nonlinear relationships with elevation. However, these parameters were not significantly correlated with SR when the effect of temperature was removed (SRref). These results demonstrate that the main factor affecting SR in forest ecosystems along this Alpine elevation gradient is temperature, but its regulating role can be strongly influenced by site biological characteristics, particularly vegetation type and structure, affecting litter quality and microclimate. This study also confirms that high elevation sites are rich in SOC and more sensitive to climate change, being prone to high C losses as CO2. Furthermore, our data indicate a positive relationship between Q10 and dominant tree height, suggesting that mature forest ecosystems characterized by an uneven-age structure, high SRref and moderate Q10, may be more resilient.
Aim: The microbial metabolic quotient (MMQ; mg CO2-C/mg MBC/h), defined as the amount of microbial CO2 respired (MR; mg CO2-C/kg soil/h) per unit of microbial biomass C (MBC; mg C/kg soil), is a key parameter for understanding the microbial regulation of the carbon (C) cycle, including soil C sequestration. Here, we experimentally tested hypotheses about the individual and interactive effects of multiple nutrient addition (nitrogen + phosphorus + potassium + micronutrients) and herbivore exclusion on MR, MBC and MMQ across 23 sites (five continents). Our sites encompassed a wide range of edaphoclimatic conditions; thus, we assessed which edaphoclimatic
variables affected MMQ the most and how they interacted with our treatments.
Location: Australia, Asia, Europe, North/South America.
Time period: 2015–2016.
Major taxa: Soil microbes.
Methods: Soils were collected from plots with established experimental treatments.
MR was assessed in a 5-week laboratory incubation without glucose addition, MBC via substrate-induced respiration. MMQ was calculated as MR/MBC and corrected
for soil temperatures (MMQsoil). Using linear mixed effects models (LMMs) and structural equation models (SEMs), we analysed how edaphoclimatic characteristics and treatments interactively affected MMQsoil.
Results: MMQsoil was higher in locations with higher mean annual temperature, lower water holding capacity and lower soil organic C concentration, but did not respond to our treatments across sites as neither MR nor MBC changed. We attributed this relative homeostasis to our treatments to the modulating influence of edaphoclimatic variables. For example, herbivore exclusion, regardless of fertilization, led to greater MMQsoil only at sites with lower soil organic C (< 1.7%).
Main conclusions: Our results pinpoint the main variables related to MMQsoil across grasslands and emphasize the importance of the local edaphoclimatic conditions in controlling the response of the C cycle to anthropogenic stressors. By testing hypotheses about MMQsoil across global edaphoclimatic gradients, this work also helps to align the conflicting results of prior studies.
Aim
Climate change causes species to shift their distributions. Individual species, however, greatly vary in their capacity to track the macroclimatic temperature increase due to differences in demography and dispersal. To better predict range shifts to climate change we need a complementary integration of long‐term empirical data and predictive modelling.
Location
Belgium and North‐West Europe.
Taxon
Hyacinthoides non‐scripta ¸ forest understorey plants.
Methods
Complementing species distribution models with demographic data from an exceptional 60‐year‐old over‐the‐range‐edge transplant experiment measured not less than 45 and 60 years after installation, we evaluated the long‐term consequences of climate change on one of the most emblematic but also among the slowest colonizing plant species of European forests, bluebell Hyacinthoides non‐scripta .
Results
We found bluebell able to establish viable populations beyond its natural range. These results were confirmed by the SDM, showing that bluebell’s potential range is considerably larger than its current range. Colonization rates of only 2 m century ⁻¹ were observed in the transplanted populations. Beyond bluebell’s current range, we observed decreasing trends in population growth rates over the past 15 years. By the end of the 21st century, substantial decreases in the southern parts of bluebell’s range were predicted.
Main conclusions
Based on empirical and modelling results, we expect serious population declines in large parts of its current natural distribution of bluebell. Although the species is able to establish viable populations beyond the natural range edge, slow demography and local colonization rates four orders of magnitude lower than the velocity of climate change make fast enough range shifts virtually impossible in this species.
Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil animals regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset collected from 2,470 sites, we estimate total soil springtail biomass at 29 Mt carbon (threefold higher than wild terrestrial vertebrates6) and record peak densities up to 2 million individuals per m2 in the Arctic. Despite a 20-fold biomass difference between tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the increase in temperature. Neither springtail density nor community metabolism were predicted by local species richness, which was highest in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation, and resource limitation7,9,10 in soil communities. Contrasting temperature responses of biomass, diversity and activity of springtail communities suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting major soil functions.
PurposeThe short growing season and cold climate of the boreal forest can restrict soil nitrogen availability, limiting plant growth and ecosystem productivity. Vascular nitrogen-fixing plants should have an advantage in low nitrogen environments. Yet, their abundance in the boreal forest is low. How nitrogen fixation is affected when temperature differences occur between the soil and air, especially in the spring when soil temperatures remain cool, has not been documented in actinorhizal shrubs.MethodsA lab study was performed on Alnus alnobetula subsp. crispa (Aiton) Raus. For 13 weeks, soil was kept at either 10˚C, 14˚C or 16˚C, independently of shoot temperature, at 20˚C.ResultsSoils at 14˚C and 10˚C inhibited whole-plant nitrogen fixation (by 53% and 68%) and photosynthesis (by 43% and 39%), respectively, compared to soils at 16˚C. Reductions in photosynthetic rate were mainly attributed to a reduction in the fixed nitrogen supply and subsequent reduction in chlorophyll formation. Photosynthesis was not reduced immediately, suggesting some utilization of a nitrogen source not supplied from current fixation. Reduced amounts of fixed nitrogen and photosynthates resulted in diminished biomass production and relative growth rate.Conclusion
The assumed advantages of being a nitrogen-fixing plant in a low nitrogen environment may be constrained by soil temperature to a larger extent than previously considered. This may restrict the abundance of nitrogen-fixing species in the boreal forest.
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