Global maps of soil temperature

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 do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur 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 soil 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 8519 unique temperature sensors) across all the world\u27s 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 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) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface 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 geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Global maps of soil temperature

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 do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur 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 soil 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 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 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) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface 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 geographic gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Global maps of soil temperature.

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 do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur 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 soil 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 8519 unique temperature sensors) across all 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 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) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface 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 geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Architecture, life history and liana infestation of tree species in semideciduous forests from Campinas, SP

Orientador: Fernando Roberto MartinsDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Lianas possuem um papel chave na dinâmica de ecossistemas florestais, principalmente no que diz respeito aos efeitos diretos exercidos sobre os forófitos, como diminuição da taxa de crescimento e reprodução e aumento da taxa de mortalidade. Nosso objetivo foi responder a três questões principais: Espécies de árvores têm diferentes susceptibilidades à infestação por lianas? Quais características arquiteturais e de história de vida dos forófitos são correlacionadas com a infestação por lianas? Árvores com 51-100% da copa coberta com lianas apresentam diferenças em alometria e desenho mecânico (fator de segurança e esbelteza do caule), comparadas às árvores congenéricas sem infestação da copa? Utilizamos um conjunto de dados previamente coletados sobre infestação da copa por lianas em 10 fragmentos de florestas semedicíduas no município de Campinas, e acrescentamos informações sobre características arquiteturais e de história de vida para 54 espécies arbóreas. Dezoito espécies apresentaram um número de indivíduos infestados que diferiu significativamente do número médio de árvores infestadas no fragmento. Com base nesses resultados classificamos as espécies em três categorias de susceptibilidade à infestação: alta, baixa e variável. No geral, as espécies arbóreas com maior infestação por lianas foram caracterizadas por altura do fuste baixa, grande profundidade da copa, tipo de casca rugosa a profundamente sulcada e fenologia foliar decídua. Em quatro espécies, os coeficientes alométricos entre altura total e diâmetro das árvores com copas infestadas foram significativamente menores que das árvores livres de lianas, com árvores infestadas mais próximas ao limite teórico de tombamento pelo modelo de similaridade elástica. Em média, o fator de segurança (diâmetro crítico para o tombamento) foi menor para as árvores infestadas. O fator de segurança e a esbelteza do caule estiveram negativamente relacionados tanto em árvores infestadas, quanto em árvores livres de lianas, mas árvores com lianas apresentaram maior valor do coeficiente do que árvores sem lianas. Espécies diferentes têm diferentes susceptibilidades a lianas. A combinação de características arquiteturais e de história de vida em forma de síndromes, como altura do fuste, profundidade da copa, fenologia foliar e tipo de casca, muito mais que cada caráter individual, influi na susceptibilidade à infestação por lianas. O fato de árvores infestadas terem menor estabilidade em relação ao limite teórico de tombamento elástico poderia implicar em maior taxa de mortalidade em relação a árvores livres de lianas.Abstract: Lianas have a key role in forest dynamics and processes in the ecosystem, and may reduce host tree growth rates, fecundity and survival. We address three main questions: Do tree species differ in their susceptibility to lianas? What host tree architectural and life history traits are correlated with the liana infestation? Tree with 51-100% of crown infestation shows difference in alometry and mechanical design (safety factor and slenderness) in relation to trees without lianas? We utilize a data set on liana infestation in ten semideciduous forest fragments of Campinas city, and we added tree architectural and life history traits for 54 tree species. Eighteen species had a higher or lower proportion of liana-infested individuals than the mean number of infested trees in the forest. The tree species was classified in three categories about to susceptibility: high, low and variable. In general, tree species with higher liana infestation were characterized by a low first branch height, high depth crown, bark type slightly rough to strongly fissured and deciduous leaves. In four species the allometric coefficient for height-diameter relations in liana-infested trees was significantly lower than liana-free trees, and liana-infested trees was more close to minimum diameter required to prevent elastic buckling in wooded columns. The safety factor and slenderness was negatively correlated for liana-infested trees and liana-free trees. However, liana-infested trees had higher slope for relationship between these two variables (safety factor and slenderness). Our results pointed out that the combination of tree architectural and life history traits as free bole height, depth crown, foliar phenology and bark type, more than each isolated feature, are important factors determining to liana infestation of tree species analyzed. We suggest that the lower mechanical stability of liana-infested trees could be a cause to higher mortality rates in those trees in comparison to trees without lianas.MestradoMestre em Biologia Vegeta

Architecture, life history and liana infestation of tree species in semideciduous forests from Campinas, SP

Orientadores: Fernando Roberto Martins, Rafael Silva OliveiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Compreender como espécies de plantas diferenciam-se em relação a atributos funcionais para aquisição e utilização de recursos, e se a relação entre esses atributos varia em função de diferenças ambientais, como pluviosidade total e sazonalidade, e uma forma de construir uma ecologia mais preditiva no contexto das mudanças climáticas globais. Nesta tese investigamos como arvores e lianas se diferenciam em relação a atributos funcionais da folha dos ramos. Analisamos-nos se o relacionamento entre esses atributos diferia considerando a variação de pluviosidade e sazonalidade de duas fitofiosionomias da Floresta Atlântica, a floresta ombrofila densa (FO) e a floresta estacional semedicidua (FS). Encontramos diferenças não são na amplitude, mas também na forca do relacionamento entre os atributos funcionais foliares estudados. Essas diferenças parecem ser determinadas pela diferença ambiental entre as duas florestas estudadas e por características intrínsecas do habito de crescimento de lianas e arvores. A anatomia do xilema das espécies de lianas e arvores da FO difere em relação à das espécies da FS, mesmo quando consideramos o parentesco filogenético. Por investir pouco em tecidos de sustentação esperava-se menor conteúdo de lignina nos ramos de lianas, entretanto nosso resulto foi o oposto. Encontramos a razão S/G dos monômeros syringil e guaiacil que compõe a lignina menor que um para duas espécies de lianas. Indicando que ha maior deposição de lignina em vasos de xilema do que em fibras. Esse fato pode estar relacionado à maior eficiência em condutividade hidráulica de lianas ou a requerimentos biomecânicos específicos dos ramos de lianas. Em particular, ressalta-se o fato de que lianas foram mais eficientes em captar luz (menor MFA) e tiveram maior condutividade hidráulica potencial (Kp) do que arvores na FS. A maior competitividade de lianas frente arvores apenas na FS tem implicação importante no cenário de mudanças climáticasAbstract: Understanding how plant species differentiated in functional traits for resources acquisition and use, and if the relationships among those traits vary in according with environmental characteristics such as rainfall and seasonality, could lead to a more predictive science in the context of global change. Here we investigate how trees and lianas differ in leaf and xylem anatomical traits related to water transport and hydraulic architecture. We analyze the relationships among those traits taking into account the variation in rainfall and seasonality between two types of Atlantic Forest, semediciduous seasonal forest (SF) and the dense ombrophilous forest (OF). We found differences not only in range, but in the strength of the relationship among leaf functional traits, which in turn could be related to environmental differences between the two forests studied. The xylem anatomy of lianas and tree species of OF differ compared to species of SF despite taking to account the phylogenetic relatedness. Since lianas have low investment in support tissues we expected lower lignin content in the branches of lianas. However, we found the opposite pattern. Another unexpected result found for two liana species was the ratio to the monomers syringyl and guayacil present at lignin (S/G) lower than one. This result indicates that there is more deposition of lignin in xylem vessel walls than fibers, what in turn would be linked to greater efficiency in hydraulic conductivity of lianas or to specific biomechanical requirements of the branches of lianas. In particular, we highlighted the fact that liana species are more efficient in light acquisition (lower LMA) and had higher hydraulic conductivity (Kp) relative to trees just in the SF. These lianas competitive advantages over trees have important implications in the context of climatic changesDoutoradoBiologia VegetalDoutor em Biologia Vegeta

Costs and benefits of gas inside wood and its relationship with anatomical traits: a contrast between trees and lianas

Gas inside wood plays an important role in plant functioning, but there has been no study examining the adaptive nature of gas inside wood across plants differing in biomechanical demands. Using a comparative approach, we measured gas volumetric content, xylem’s anatomical traits and wood density of 15 tree and 16 liana species, to test whether gas content varies between these plant types strongly differing in their biomechanical demands. We asked (i) whether trees and lianas differ in gas content and (ii) how anatomical traits and wood density are related to gas content. Lianas had significantly less gas content in their branches compared with tree species. In tree species, gas content scaled positively with fiber, vessel and xylem cross-sectional area and fiber and vessel diameter, and negatively with dry-mass density. When pooling trees and lianas together, fiber cross-sectional area was the strongest predictor of gas content, with higher xylem cross-sectional area of fiber associated with higher gas content. In addition, we showed, through a simple analytical model, that gas inside wood increases the minimum branch diameter needed to prevent rupture, and this effect was stronger on trees compared with lianas. Our results support the view that gas inside wood plays an important role in the evolution of biomechanical functioning in different plant forms. Gas inside wood may also play an important role in physiological activities such as water transport, storage, photosynthesis and respiration, but it is still unknown whether these roles are or are not secondary to the mechanical support407856868CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP233206/2014-0; 301926/2013-12010/1145