Dataset Information

Spatiotemporal variability of soil respiration in a seasonal tropical forest.

ABSTRACT: We monitored soil CO ₂ effluxes for over 3 years in a seasonally wet tropical forest in Central Panama using automated and manual measurements from 2013 to 2016. The measurements displayed a high degree of spatial and temporal variability. Temporal variability could be largely explained by surface soil water dynamics over a broad range of temporal scales. Soil moisture was responsible for seasonal cycles, diurnal cycles, intraseasonal variability such as rain-induced pulses following dry spells, as well as suppression during near saturated conditions, and ultimately, interannual variability. Spatial variability, which remains largely unexplained, revealed an emergent role of forest structure in conjunction with physical drivers such as soil temperature and topography. Mean annual soil CO ₂ effluxes (±SE) amounted to 1,613 (±59) gC m^-2 year^-1 with an increasing trend in phase with an El Niño/Southern Oscillation (ENSO) cycle which culminated with the strong 2015-2016 event. We attribute this trend to a relatively mild wet season during which soil saturated conditions were less persistent.

SUBMITTER: Rubio VE

PROVIDER: S-EPMC5587468 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Spatiotemporal variability of soil respiration in a seasonal tropical forest.

Rubio Vanessa E VE Detto Matteo M

Ecology and evolution 20170814 17

We monitored soil CO <sub>2</sub> effluxes for over 3 years in a seasonally wet tropical forest in Central Panama using automated and manual measurements from 2013 to 2016. The measurements displayed a high degree of spatial and temporal variability. Temporal variability could be largely explained by surface soil water dynamics over a broad range of temporal scales. Soil moisture was responsible for seasonal cycles, diurnal cycles, intraseasonal variability such as rain-induced pulses following ...[more]

PMID: 28904787

Similar Datasets

Project description:Soil respiration in forests contributes to significant carbon dioxide emissions from terrestrial ecosystems but it varies both spatially and seasonally. Both abiotic and biotic factors influence soil respiration but their relative contribution to spatial and seasonal variability remains poorly understood, which leads to uncertainty in models of global C cycling and predictions of future climate change. Here, we hypothesize that tree diversity, soil diversity, and soil properties contribute to local-scale variability of soil respiration but their relative importance changes in different seasons. To test our hypothesis, we conducted seasonal soil respiration measurements along a local-scale environmental gradient in a temperate forest in Northeast China, analyzed spatial variability of soil respiration and tested the relationships between soil respiration and a variety of abiotic and biotic factors including topography, soil chemical properties, and plant and soil diversity. We found that soil respiration varied substantially across the study site, with spatial coefficients of variation (CV) of 29.1%, 27.3% and 30.8% in spring, summer, and autumn, respectively. Soil respiration was consistently lower at high soil water content, but the influence of other factors was seasonal. In spring, soil respiration increased with tree diversity and biomass but decreased with soil fungal diversity. In summer, soil respiration increased with soil temperature, whereas in autumn, soil respiration increased with tree diversity but decreased with increasing soil nutrient content. However, soil nutrient content indirectly enhanced soil respiration via its effect on tree diversity across seasons, and forest stand structure indirectly enhanced soil respiration via tree diversity in spring. Our results highlight that substantial differences in soil respiration at local scales was jointly explained by soil properties (soil water content and soil nutrients), tree diversity, and soil fungal diversity but the relative importance of these drivers varied seasonally in our temperate forest.

Project description:Global change is affecting primary productivity in forests worldwide, and this, in turn, will alter long-term carbon (C) sequestration in wooded ecosystems. On one hand, increased primary productivity, for example, in response to elevated atmospheric carbon dioxide (CO 2), can result in greater inputs of organic matter to the soil, which could increase C sequestration belowground. On other hand, many of the interactions between plants and microorganisms that determine soil C dynamics are poorly characterized, and additional inputs of plant material, such as leaf litter, can result in the mineralization of soil organic matter, and the release of soil C as CO 2 during so-called "priming effects". Until now, very few studies made direct comparison of changes in soil C dynamics in response to altered plant inputs in different wooded ecosystems. We addressed this with a cross-continental study with litter removal and addition treatments in a temperate woodland (Wytham Woods) and lowland tropical forest (Gigante forest) to compare the consequences of increased litterfall on soil respiration in two distinct wooded ecosystems. Mean soil respiration was almost twice as high at Gigante (5.0 μmol CO 2 m-2 s-1) than at Wytham (2.7 μmol CO 2 m-2 s-1) but surprisingly, litter manipulation treatments had a greater and more immediate effect on soil respiration at Wytham. We measured a 30% increase in soil respiration in response to litter addition treatments at Wytham, compared to a 10% increase at Gigante. Importantly, despite higher soil respiration rates at Gigante, priming effects were stronger and more consistent at Wytham. Our results suggest that in situ priming effects in wooded ecosystems track seasonality in litterfall and soil respiration but the amount of soil C released by priming is not proportional to rates of soil respiration. Instead, priming effects may be promoted by larger inputs of organic matter combined with slower turnover rates.

Project description:Soil microbiomes play an essential role in maintaining soil geochemical cycle and function. Although there have been some reports on the diversity patterns and drivers of the tropical forest soil microbial community, how space and seasonal changes affect spatiotemporal distribution at the regional scales are poorly understood. Based on 260 soil samples, we investigated the spatiotemporal patterns of rubber plantations and rainforest soil microbial communities across the whole of Hainan Island, China during the dry and rainy seasons. We examined soil bacterial and fungal composition and diversity and the main drivers of these microbes using Illumina sequencing and assembly. Our results revealed that the diversity (both alpha and beta) spatiotemporal variation in microbial communities is highly dependent on regional location rather than seasonal changes. For example, the site explained 28.5% and 37.2% of the variation in alpha diversity for soil bacteria and fungi, respectively, and explained 34.6% of the bacterial variance and 14.3% of the fungal variance in beta diversity. Soil pH, mean annual temperature, and mean annual precipitation were the most important factors associated with the distribution of soil microbial communities. Furthermore, we identified that variations in edaphic (e.g., soil pH) and climatic factors (e.g., mean annual temperature [MAT] and mean annual precipitation [MAP]) were mainly caused by regional sites (P < 0.001). Collectively, our work provides empirical evidence that space, rather than seasonal changes, explained more of the spatiotemporal variation of soil microbial communities in tropical forests, mediated by regional location-induced changes in climatic factors and edaphic properties. IMPORTANCE The soil microbiomes communities of the two forests were not only affected by environmental factors (e.g., edaphic and climatic factors), but also by different dominant geographic factors. In particular, our work showed that spatial variation in bacterial and fungal community composition was mainly dominated by edaphic properties (e.g., pH) and climatic factors (e.g., MAT and MAP). Moreover, the environmental factors were mainly explained by geographic location effect rather than by seasonal effect, and environmental dissimilarity significantly increased with geographic distance. In conclusion, our study provides solid empirical evidence that space rather than season explained more of the spatiotemporal variation of soil microbial communities in the tropical forest.

Dataset Information

Spatiotemporal variability of soil respiration in a seasonal tropical forest.

Publications

Spatiotemporal variability of soil respiration in a seasonal tropical forest.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets