Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries
Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids thus fail to reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions are controlled and most terrestrial species reside. Here we provide global maps of soil temperature and bioclimatic variables at a 1-km² resolution for 0-5 and 5-15 cm depth. These maps were created by calculating the difference (i.e., offset) between in-situ soil temperature measurements, based on time series from over 1200 1-km² pixels (summarized from 8500 unique temperature sensors) across all of the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding 2 m gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (3.6 ± 2.3°C warmer than gridded air temperature), whereas soils in warm and humid environments are on average slightly cooler (0.7 ± 2.3°C cooler). The observed substantial and biome-specific offsets underpin that the projected 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. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining global gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.
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.
Tropical forests store 40-50% of terrestrial vegetation carbon 1 . Spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests 2 . Owing to climatic and soil changes with increasing elevation 3 , AGC stocks are lower in tropical montane compared to lowland forests 2 . Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC-stock of 149.4 Mg C ha -1 (95% CI 137.1-164.2), comparable to lowland forests in the African Tropical Rainforest Observation Network 4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane 2,5,6 and lowland 7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the IPCC default values for these forests in Africa 8 . We find that the low stem density and high abundance of large trees of African lowland forests 4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million ha of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse 9,10 and carbon-rich ecosystems.
Mineral composition of dry Tamarindus indica LINN pulp and seeds was evaluated on samples collected from three different agro‐ecological zones of Uganda (Lake Victoria Crescent, and Eastern and West Nile). The objective of the study was to evaluate the mineral composition of T. indica pulp and seed samples from across Uganda's different agro‐ecological zones and land use types. Separately grounded samples of T. indica pulp and seeds were analyzed for Zn, Fe, Mg, P, Na, K, and Ca. The univariate analysis of variance in the General Linear Model was used to compare differences in mineral composition. Treatment means were separated using Least Significant Difference (LSD) in Post Hoc Tests. The results showed that there were significant differences (p ≤ 0.005) in mineral composition levels of T. indica pulp and seed samples between the different agro‐ecological zones with the exception of P and Na (for pulp). The T. indica pulp and seeds samples from the Lake Victoria Crescent zone and wild land use type had generally higher mineral levels than T. indica samples from other agro‐ecological zones and different land use types. As mineral composition levels were generally higher in the seed than the pulp samples, consumption of T. indica seeds should be promoted. There is also need to conserve individual species both on‐farm and in the wild population, but T. indica mineral concentrations (both pulp and seeds) were higher in the samples from the wild population, making them good for human and animal diets.
The relationships between the physicochemical composition of Tamarindus indica pulp and seeds, and agro‐ecological zones and land use types were assessed in Uganda. The objective was to determine the relationship between the physicochemical composition, agro‐ecological zones, and land use types. The samples were processed by manually depulping the T. indica pods, sun‐drying the pulp and seeds, and grinding into powder. The powdered samples were analyzed for β‐carotenoids, vitamin C (ascorbic acid), calorific value, crude oil, acid, and peroxide values. Data were analyzed using ANOVA in the general linear model (GLM). Principal component analysis (PCA) was used to relate the physicochemical properties to the agro‐ecological zones and land use types. There were significant differences (p ≤ .05) in the physicochemical composition variables between agro‐ecological zones and land use types. Land use types showed strong correlations with physicochemical properties while agro‐ecological zones did not show correlations. The results show that in terms of general properties, T. indica pods provide a valuable, rich, and exceptional source of vitamin C, compared to many widely consumed indigenous and conventional fruits and vegetables. The pods from land use types characterized by natural habitats had relatively more nutrient levels than the land use types influenced by anthropogenic activities.
An investigation was carried out on variations in the morphological traits ofTamarindus indicaLINN. fruits (length, breadth, mass, and pulp mass) and seeds (number and mass) from the different agroecological zones and land use types of Uganda. Fruits were collected from the two land use types in the three agroecological zones and measured for various morphological traits. The study sites were located between 593 and 1,096 meters above sea level. ANOVA was used to test the differences in morphological traits of fruits and seeds between agroecological zones and land use types. The morphological traits relationship was determined using Pearson Correlation Coefficient (R). There were significant (P≤0.05) variations among theT. indicafruits and seed morphological traits within the agroecological zones and land use types. Lake Victoria Crescent agroecological zone recorded higher fruits morphological traits values. Wild and on-farm land use types were superior in fruits and seed traits, respectively. Many seeds per fruit (17) were recorded in Uganda (Eastern agroecological zone) than those recorded elsewhere. Significant uphill positive linear correlations between all morphological traits (P≤0.05) were observed, with the strongest relationships being between seed mass and seed number (R=0.79), fruit mass and fruit length (R=0.75), pulp mass and fruit mass (R=0.73), and seed mass and fruit mass (R=0.73). However, fruit breadth presented slightly weaker positive linear correlations with all other morphological traits. This is the first quantitative evaluation ofT. indicamorphological traits variation in Uganda. Dispersion/variation and correlation relationships suggest that all the studied morphological traits can be used for selection of plus trees for tree breeding improvement such as yield per tree. The observed variations are probably attributed to influence of agroecological zones’ factors, environmental factors, climate, land use types, and farming systems, a reflection ofT. indicaadaptation to different conditions showing high genetic and phenotypic differences to be exploited.
Montane forests are characterized by high biodiversity, endemism, and strong elevational environmental gradients. The latter attribute makes them also suitable as a “natural laboratory” for studying the effects of environmental parameters on ecosystem functions. To provide better insight into the carbon cycle of Afromontane ecosystems, we used an elevational gradient approach to quantify carbon stocks, woody and litter productivity, and their constraining factors. Twenty plots were established, covering five elevations from Kibale Forest at 1250 m to 3000 m in the Rwenzori Mountains. Results revealed aboveground carbon stocks of between 185.4 ± 48.9 and 70.8 ± 18.6 Mg C ha−1 at 1250–1300 and 2700–3000 m, respectively. Aboveground carbon tended to decrease with elevation, but this trend was not significant. This was due to similarities in stem diameter combined with different effects of tree height and stem density. Similarly, woody productivity did not change with elevation, ranging from 8.3 ± 4.1 to 3.4 ± 1.5 Mg C ha−1 year−1 at 2500–2600 and 2700–3000 m, respectively. However, litter productivity decreased linearly by 0.14 ± 0.04 Mg C ha−1 year−1 per 100 m of elevation increase, ranging from 4.0 ± 0.7 Mg C ha−1 year−1 at 1750–1850 m to 1.2 Mg C ha−1 year−1 at 2700–3000 m. Topsoil physicochemical properties varied with elevation, but showed no significant relationship with carbon stocks and woody productivity. However, litter productivity increased with mean soil temperature, whereas it decreased with soil total nitrogen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.