Mammalian herbivores play a pivotal role in Earth System processes by affecting biogeochemical cycles and ecosystem functioning, potentially leading to significant repercussions on atmosphere\uffe2\uff80\uff93biosphere feedbacks. Global dynamic models of mammalian populations can improve our understanding of their ecological role at large scales and the consequences of their extinctions. However, such models are still lacking and mammals are poorly integrated in Earth System Science.
We developed a mechanistic global model of terrestrial herbivore populations simulated with 37 functional groups defined through the analysis of eco\uffe2\uff80\uff90physiological traits across all extant herbivores (2599 species). We coupled this model with a global vegetation model to predict herbivores' maximum potential biomass in pre\uffe2\uff80\uff90industrial and at present\uffe2\uff80\uff90day and to study the environmental drivers explaining the distribution of herbivore biomass. Present\uffe2\uff80\uff90day biomass was estimated by accounting for anthropogenic activity causing habitat and range losses.
We show that natural ecosystems could have sustained a potential wild herbivore wet biomass of 330 Mt (95% CI: 245\uffe2\uff80\uff93417), comprised of 193 Mt (95% CI: 177\uffe2\uff80\uff93208) by large species (body mass >1\uffe2\uff80\uff9310\uffe2\uff80\uff89kg, depending on functional group) and 138 Mt (95% CI: 68\uffe2\uff80\uff93209) by small species. We estimate that the remaining present\uffe2\uff80\uff90day large herbivores biomass is 82 Mt (95% CI: 32\uffe2\uff80\uff93133), reduced by 57% due to anthropogenic activity; consequently, small herbivores currently dominate global herbivore biomass with 98 Mt (95% CI: 91\uffe2\uff80\uff93106, \uffe2\uff88\uff9229%). Losses vary greatly across climatic zones and functional groups, suggesting that size is not the only discriminant feature of biomass decline.
Actual evapotranspiration is the most important driver of total, large and small herbivore biomass and explains 64%, 59% and 49% of its variation, respectively. Distribution of modelled and observed large herbivores' biomass suggested a high dependency on energy and water with more biomass in hot and wet areas. These results challenge the notion that large herbivore biomass peaks primarily in ecosystems with intermediate precipitation levels such as savannas.
Outside Africa and the Tropics, pre\uffe2\uff80\uff90industrial biomass hotspots occur in areas today dominated by humans; this could undermine the recovery of larger species biomass in certain areas. Our herbivore biomass estimates provide a quantitative benchmark for setting conservation and rewilding goals at large spatial scales. The herbivore model and functional classification create new opportunities to integrate mammals into Earth System Science and models.
Read the free Plain Language Summary for this article on the Journal blog. Sedimentation is one of the limiting factors for coral life. Suspended and deposited sediment have negative effects on the coral community. The rate of sedimentation can lead to low coral cover, low growth rate and low recruitment. Sediment that enters inner Ambon bay comes from 8 rivers around the bay. In this research, we assess coral reefs condition, calculate the rate of sedimentation, analyze effects of sedimentation on the coral reefs, and observe the change of coral reefs condition in inner Ambon Bay. Distribution and general condition of coral reefs was observed using manta tow method. Three places were then chosen to be surveyed in detail using line intercept transect to determine the percentage of coral cover. Resuspendedsedimet were measured by using sediment traps placed on coral reefs for 3 days. Sea water was collected with Niskin bottle, filtered and analyzed in laboratory to determine suspended particulate matter. The results showed that percentage of coral cover in Hunut, Kate-Kate and Halong are 5.62%, 5.26%, and 8.92% respectively and fall into the category of poor coral reef condition. The percentage of coral cover decreased progressively since 1985. The suspended particulate matter in three locations is more than 20 mg/l and resuspension sediment at Kate-kate is 18.39 mg/cm2/day, Hunut 16.29 mg/cm2/day, and Halong 10.12 mg/cm2/day. The degree of sedimentation in inner Ambon Bay is at the level of moderate to severe.Previous laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale.
MethodsA field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield.
Key ResultsMeasurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in a less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought.
ConclusionsSelecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder\uffe2\uff80\uff99s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.Gypsum drylands are widespread worldwide. In these arid ecosystems, the ability of different species to access different water sources during drought is a key determining factor of the composition of plant communities. Gypsum crystallization water could be a relevant source of water for shallow-rooted plants, but the segregation in the use of this source of water among plants remains unexplored. We analysed the principal water sources used by 20 species living in a gypsum hilltop, the effect of rooting depth and gypsum affinity, and the interaction of the plants with the soil beneath them.
MethodsWe characterized the water stable isotope composition, \uffce\uffb4\uffe2\uff80\uff8a2H and \uffce\uffb4\uffe2\uff80\uff8a18O, of plant xylem water and related it to the free and gypsum crystallization water extracted from different depths throughout the soil profile and the groundwater, in both spring and summer. Bayesian isotope mixing models were used to estimate the contribution of water sources to plant xylem sap.
Key ResultsIn spring, all species used free water from the top soil as the main source. In summer, there was segregation in water sources used by different species depending on their rooting depth, but not on their gypsum affinity. Gypsum crystallization water was the main source for most shallow-rooted species, whereas free water from 50 to 100 cm depth was the main source for deep-rooted species. We detected plant\uffe2\uff80\uff93soil interactions in spring, and indirect evidence of possible hydraulic lift by deep-rooted species in summer.
ConclusionsPlants coexisting in gypsum communities segregate their hydrological niches according to their rooting depth. Crystallization water of gypsum represents an unaccounted for, vital source for most of the shallow-rooted species growing on gypsum drylands. Thus, crystallization water helps shallow-rooted species to endure arid conditions, which eventually accounts for the maintenance of high biodiversity in these specialized ecosystems.Phosphorus (P) is an essential macro\uffe2\uff80\uff90nutrient required for plant metabolism and growth. Low P availability could potentially limit plant responses to elevated carbon dioxide (eCO2), but consensus has yet to be reached on the extent of this limitation. Here, based on data from experiments that manipulated both CO2 and P for young individuals of woody and non\uffe2\uff80\uff90woody species, we present a meta\uffe2\uff80\uff90analysis of P limitation impacts on plant growth, physiological, and morphological response to eCO2. We show that low P availability attenuated plant photosynthetic response to eCO2 by approximately one\uffe2\uff80\uff90quarter, leading to a reduced, but still positive photosynthetic response to eCO2 compared to those under high P availability. Furthermore, low P limited plant aboveground, belowground, and total biomass responses to eCO2, by 14.7%, 14.3%, and 12.4%, respectively, equivalent to an approximate halving of the eCO2 responses observed under high P availability. In comparison, low P availability did not significantly alter the eCO2\uffe2\uff80\uff90induced changes in plant tissue nutrient concentration, suggesting tissue nutrient flexibility is an important mechanism allowing biomass response to eCO2 under low P availability. Low P significantly reduced the eCO2\uffe2\uff80\uff90induced increase in leaf area by 14.3%, mirroring the aboveground biomass response, but low P did not affect the eCO2\uffe2\uff80\uff90induced increase in root length. Woody plants exhibited stronger attenuation effect of low P on aboveground biomass response to eCO2 than non\uffe2\uff80\uff90woody plants, while plants with different mycorrhizal associations showed similar responses to low P and eCO2 interaction. This meta\uffe2\uff80\uff90analysis highlights crucial data gaps in capturing plant responses to eCO2 and low P availability. Field\uffe2\uff80\uff90based experiments with longer\uffe2\uff80\uff90term exposure of both CO2 and P manipulations are critically needed to provide ecosystem\uffe2\uff80\uff90scale understanding. Taken together, our results provide a quantitative baseline to constrain model\uffe2\uff80\uff90based hypotheses of plant responses to eCO2 under P limitation, thereby improving projections of future global change impacts.
", "keywords": ["0106 biological sciences", "910", "01 natural sciences", "XXXXXX - Unknown", "soil phosphorus", "Humans", "phosphorus", "Photosynthesis", "mycorrhizae", "soils", "Ecosystem", "0105 earth and related environmental sciences", "580", "nutrient concentration", "2. Zero hunger", "plant morphology", "biomass", "plants", "carbon dioxide", "Phosphorus", "mycorrhizas", "04 agricultural and veterinary sciences", "Carbon Dioxide", "Plants", "15. Life on land", "leaf gas exchange", "meta-analysis", "plant nutrient uptake", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.15277"}, {"href": "https://doi.org/10.1111/gcb.15277"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/gcb.15277", "name": "item", "description": "10.1111/gcb.15277", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/gcb.15277"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-07-31T00:00:00Z"}}, {"id": "10.1093/ismejo/wrae025", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-03T16:19:31Z", "type": "Journal Article", "created": "2024-02-12", "title": "Stronger compensatory thermal adaptation of soil microbial respiration with higher substrate availability", "description": "AbstractOngoing global warming is expected to augment soil respiration by increasing the microbial activity, driving self-reinforcing feedback to climate change. However, the compensatory thermal adaptation of soil microorganisms and substrate depletion may weaken the effects of rising temperature on soil respiration. To test this hypothesis, we collected soils along a large-scale forest transect in eastern China spanning a natural temperature gradient, and we incubated the soils at different temperatures with or without substrate addition. We combined the exponential thermal response function and a data-driven model to study the interaction effect of thermal adaptation and substrate availability on microbial respiration and compared our results to those from two additional continental and global independent datasets. Modeled results suggested that the effect of thermal adaptation on microbial respiration was greater in areas with higher mean annual temperatures, which is consistent with the compensatory response to warming. In addition, the effect of thermal adaptation on microbial respiration was greater under substrate addition than under substrate depletion, which was also true for the independent datasets reanalyzed using our approach. Our results indicate that thermal adaptation in warmer regions could exert a more pronounced negative impact on microbial respiration when the substrate availability is abundant. These findings improve the body of knowledge on how substrate availability influences the soil microbial community\uffe2\uff80\uff93temperature interactions, which could improve estimates of projected soil carbon losses to the atmosphere through respiration. Humus samples were collected 12 growing seasons after the start of a simulated acid rain experiment situated in the subarctic environment. The acid rain was simulated with H 2 SO 4 , a combination of H 2 SO 4 and HNO 3 , and HNO 3 at two levels of moderate acidic loads close to the natural anthropogenic pollution levels of southern Scandinavia. The higher levels of acid applications resulted in acidification, as defined by humus chemistry. The concentrations of base cations decreased, while the concentrations of exchangeable H + , Al, and Fe increased. Humus pH decreased from 3.83 to 3.65. Basal respiration decreased with decreasing humus pH, and total microbial biomass, measured by substrate-induced respiration and total amount of phospholipid fatty acids (PLFA), decreased slightly. An altered PLFA pattern indicated a change in the microbial community structure at the higher levels of acid applications. In general, branched fatty acids, typical of gram-positive bacteria, increased in the acid plots. PLFA analysis performed on the bacterial community growing on agar plates also showed that the relative amount of PLFA specific for gram-positive bacteria increased due to the acidification. The changed bacterial community was adapted to the more acidic environment in the acid-treated plots, even though bacterial growth rates, estimated by thymidine and leucine incorporation, decreased with pH. Fungal activity (measured as acetate incorporation into ergosterol) was not affected. This result indicates that bacteria were more affected than fungi by the acidification. The capacity of the bacterial community to utilize 95 different carbon sources was variable and only showed weak correlations to pH. Differences in the toxicities of H 2 SO 4 and HNO 3 for the microbial community were not found.
", "keywords": ["2. Zero hunger", "toleranssi", "570", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "hapan sade", "mikrobiyhteis\u00f6", "04 agricultural and veterinary sciences", "Biological Sciences", "15. Life on land", "6. Clean water"], "contacts": [{"organization": "Pennanen, T., Fritze, H., Vanhala, P., Kiikkil\u00e4, O., Neuvonen, S., B\u00e5\u00e5th, E.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1128/aem.64.6.2173-2180.1998"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Applied%20and%20Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1128/aem.64.6.2173-2180.1998", "name": "item", "description": "10.1128/aem.64.6.2173-2180.1998", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1128/aem.64.6.2173-2180.1998"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1998-06-01T00:00:00Z"}}, {"id": "10.1093/nsr/nwab120", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-03T16:19:33Z", "type": "Journal Article", "created": "2021-06-29", "title": "Significant loss of soil inorganic carbon at the continental scale", "description": "AbstractWidespread soil acidification due to atmospheric acid deposition and agricultural fertilization may greatly accelerate soil carbonate dissolution and CO2 release. However, to date, few studies have addressed these processes. Here, we use meta-analysis and nationwide-survey datasets to investigate changes in soil inorganic carbon (SIC) stocks in China. We observe an overall decrease in SIC stocks in topsoil (0\uffe2\uff80\uff9330\uffc2\uffa0cm) (11.33\uffc2\uffa0g C m\uffe2\uff80\uff932 yr\uffe2\uff80\uff931) from the 1980s to the 2010s. Total SIC stocks have decreased by \uffe2\uff88\uffbc8.99\uffc2\uffa0\uffc2\uffb1\uffc2\uffa02.24% (1.37\uffc2\uffa0\uffc2\uffb1\uffc2\uffa00.37\uffc2\uffa0Pg C). The average SIC losses across China (0.046 Pg C yr\uffe2\uff80\uff931) and in cropland (0.016 Pg C yr\uffe2\uff80\uff931) account for \uffe2\uff88\uffbc17.6%\uffe2\uff80\uff9324.0% of the terrestrial C sink and 57.1% of the soil organic carbon sink in cropland, respectively. Nitrogen deposition and climate change have profound influences on SIC cycling. We estimate that \uffe2\uff88\uffbc19.12%\uffe2\uff80\uff9319.47% of SIC stocks will be further lost by 2100. The consumption of SIC may offset a large portion of global efforts aimed at ecosystem carbon sequestration, which emphasizes the importance of achieving a better understanding of the indirect coupling mechanisms of nitrogen and carbon cycling and of effective countermeasures to minimize SIC loss.Rice (Oryza sativa L.) and many other wetland plants form an apoplastic barrier in the outer parts of the roots to restrict radial O2 loss to the rhizosphere during soil flooding. This barrier facilitates longitudinal internal O2 diffusion via gas-filled tissues from shoot to root apices, enabling root growth in anoxic soils. We tested the hypothesis that Leaf Gas Film 1 (LGF1), which influences leaf hydrophobicity in rice, plays a crucial role in tight outer apoplastic barrier formation in rice roots. We examined the roots of a rice mutant (dripping wet leaf 7, drp7) lacking functional LGF1, its wild type, and an LGF1 overexpression line for their capacity to develop outer apoplastic barriers that restrict radial O2 loss. We quantified the chemical composition of the outer part of the root and measured radial O2 diffusion from intact roots. The drp7 mutant exhibited a weak barrier to radial O2 loss compared to the wild type. However, introducing functional LGF1 into the mutant fully restored tight barrier function. The formation of a tight barrier to radial O2 loss was associated with increased glycerol ester levels in exodermal cells, rather than differences in total root suberization or lignification. These results demonstrate that, in addition to its role in leaf hydrophobicity regulation, LGF1 plays an important role in controlling the function of the outer apoplastic barriers in roots. Our study suggests that increased deposition of glycerol esters in the suberized root exodermis establishes a tight barrier to radial O2 loss in rice roots.