scholarly journals Temperature sensitivity of termites determines global wood decay rates

2022 ◽  
Author(s):  
Amy Zanne ◽  
Habacuc Flores-Moreno ◽  
Jeff Powell ◽  
William Cornwell ◽  
James Dalling ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Temperature Sensitivity ◽  
Wood Decay ◽  
Biogeochemical Cycles ◽  
Global Scale ◽  
Decay Rates ◽  
Site Specific ◽  
Temperature And Precipitation ◽  
Temperature Decay ◽  
Seasonal Forests

Abstract Animals, such as termites, have largely been overlooked as global-scale drivers of biogeochemical cycles1,2, despite site-specific findings3,4. Deadwood turnover, an important component of the carbon cycle, is driven by multiple decay agents. Studies have focused on temperate systems5,6, where microbes dominate decay7. Microbial decay is sensitive to temperature, typically doubling per 10°C increase (decay effective Q10 = ~2)8–10. Termites are important decayers in tropical systems3,11–13 and differ from microbes in their population dynamics, dispersal, and substrate discovery14–16, meaning their climate sensitivities also differ. Using a network of 133 sites spanning 6 continents, we report the first global field-based quantification of temperature and precipitation sensitivities for termites and microbes, providing novel understandings of their response to changing climates. Temperature sensitivity of microbial decay was within previous estimates. Termite discovery and consumption were both much more sensitive to temperature (decay effective Q10 = 6.53), leading to striking differences in deadwood turnover in areas with and without termites. Termite impacts were greatest in tropical seasonal forests and savannas and subtropical deserts. With tropicalization17 (i.e., warming shifts to a tropical climate), the termite contribution to global wood decay will increase as more of the earth’s surface becomes accessible to termites.

scholarly journals Changes in Temperature and Precipitation Extremes in Superparameterized CAM in Response to Warmer SSTs

2017 ◽  
Vol 30 (24) ◽  
pp. 9827-9845 ◽  
Author(s):  
Xin Zhou ◽  
Marat F. Khairoutdinov
Keyword(s):  
Large Scale ◽  
Rain Rate ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Global Scale ◽  
Precipitation Extremes ◽  
Temperature And Precipitation ◽  
Hourly Data ◽  
Cloud Resolving Model ◽  
Cold Extremes

Subdaily temperature and precipitation extremes in response to warmer SSTs are investigated on a global scale using the superparameterized (SP) Community Atmosphere Model (CAM), in which a cloud-resolving model is embedded in each CAM grid column to simulate convection explicitly. Two 10-yr simulations have been performed using present climatological sea surface temperature (SST) and perturbed SST climatology derived from the representative concentration pathway 8.5 (RCP8.5) scenario. Compared with the conventional CAM, SP-CAM simulates colder temperatures and more realistic intensity distribution of precipitation, especially for heavy precipitation. The temperature and precipitation extremes have been defined by the 99th percentile of the 3-hourly data. For temperature, the changes in the warm and cold extremes are generally consistent between CAM and SP-CAM, with larger changes in warm extremes at low latitudes and larger changes in cold extremes at mid-to-high latitudes. For precipitation, CAM predicts a uniform increase of frequency of precipitation extremes regardless of the rain rate, while SP-CAM predicts a monotonic increase of frequency with increasing rain rate and larger change of intensity for heavier precipitation. The changes in 3-hourly and daily temperature extremes are found to be similar; however, the 3-hourly precipitation extremes have a significantly larger change than daily extremes. The Clausius–Clapeyron scaling is found to be a relatively good predictor of zonally averaged changes in precipitation extremes over midlatitudes but not as good over the tropics and subtropics. The changes in precipitable water and large-scale vertical velocity are equally important to explain the changes in precipitation extremes.

scholarly journals Virus-mediated archaeal hecatomb in the deep seafloor

2016 ◽  
Vol 2 (10) ◽  
pp. e1600492 ◽  
Author(s):  
Roberto Danovaro ◽  
Antonio Dell’Anno ◽  
Cinzia Corinaldesi ◽  
Eugenio Rastelli ◽  
Ricardo Cavicchioli ◽  
...  
Keyword(s):  
Viral Infection ◽  
Deep Sea ◽  
Viral Infections ◽  
Biogeochemical Cycles ◽  
Global Scale ◽  
Viral Lysis ◽  
Group I ◽  
Global Biogeochemical Cycles ◽  
Bacterial Genes ◽  
The Impact

Viruses are the most abundant biological entities in the world’s oceans, and they play a crucial role in global biogeochemical cycles. In deep-sea ecosystems, archaea and bacteria drive major nutrient cycles, and viruses are largely responsible for their mortality, thereby exerting important controls on microbial dynamics. However, the relative impact of viruses on archaea compared to bacteria is unknown, limiting our understanding of the factors controlling the functioning of marine systems at a global scale. We evaluate the selectivity of viral infections by using several independent approaches, including an innovative molecular method based on the quantification of archaeal versus bacterial genes released by viral lysis. We provide evidence that, in all oceanic surface sediments (from 1000- to 10,000-m water depth), the impact of viral infection is higher on archaea than on bacteria. We also found that, within deep-sea benthic archaea, the impact of viruses was mainly directed at members of specific clades of Marine Group I Thaumarchaeota. Although archaea represent, on average, ~12% of the total cell abundance in the top 50 cm of sediment, virus-induced lysis of archaea accounts for up to one-third of the total microbial biomass killed, resulting in the release of ~0.3 to 0.5 gigatons of carbon per year globally. Our results indicate that viral infection represents a key mechanism controlling the turnover of archaea in surface deep-sea sediments. We conclude that interactions between archaea and their viruses might play a profound, previously underestimated role in the functioning of deep-sea ecosystems and in global biogeochemical cycles.

scholarly journals Applying Geospatial Semantic Array Programming for a Reproducible Set of Bioclimatic Indices in Europe

2014 ◽  
Author(s):  
Giovanni Caudullo
Keyword(s):  
Mathematical Formulation ◽  
Open Data ◽  
Global Scale ◽  
Ecological Niches ◽  
European Continent ◽  
Bioclimatic Indices ◽  
Temperature And Precipitation ◽  
Food And Agriculture ◽  
Fuzzy Similarity ◽  
Terrain Elevation

Bioclimate-driven regression analysis is a widely used approach for modelling ecological niches and zonation. Although the bioclimatic complexity of the European continent is high, a particular combination of 12 climatic and topographic covariates was recently found able to reliably reproduce the ecological zoning of the Food and Agriculture Organization of the United Nations (FAO) for forest resources assessment at pan-European scale, generating the first fuzzy similarity map of FAO ecozones in Europe. The reproducible procedure followed to derive this collection of bioclimatic indices is now presented. It required an integration of data-transformation modules (D-TM) using geospatial tools such as Geographic Information System (GIS) software, and array-based mathematical implementation such as semantic array programming (SemAP). Base variables, intermediate and final covariates are described and semantically defined by providing the workflow of D-TMs and the mathematical formulation following the SemAP notation. Source layers to derive base variables were extracted by exclusively relying on global-scale public open geodata in order for the same set of bioclimatic covariates to be reproducible in any region worldwide. In particular, two freely available datasets were exploited for temperature and precipitation (WorldClim) and elevation (Global Multi-resolution Terrain Elevation Data). The working extent covers the European continent to the Urals with a resolution of 30 arc-second. The proposed set of bioclimatic covariates will be made available as open data in the European Forest Data Centre (EFDAC). The forthcoming complete set of D-TM codelets will enable the 12 covariates to be easily reproduced and expanded through free software. .......................................................................................................................This.manuscript.has.been.accepted.for.publication.in IEEE Earthzine 2014 Vol. 7 Issue 2, 2ndquarter theme: Geospatial Semantic Array Programming. The definitive version has been published at: http://www.earthzine.org/?p=877975......................................................................................................................Please,.cite.the.definitive.version.of.the.article.as: Caudullo, G., 2014.Applying Geospatial Semantic Array Programming for a Reproducible Set of Bioclimatic Indices in Europe.IEEE Earthzine 7(2), 877975+. URL http://www.earthzine.org/?p=877975 bioRxiv pre-print doi: 10.1101/009589

scholarly journals Space and time predictions of schistosomiasis snail host population dynamics across hydrologic regimes in Burkina Faso

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Javier Perez-Saez ◽  
Theophile Mande ◽  
Andrea Rinaldo
Keyword(s):  
Population Dynamics ◽  
Burkina Faso ◽  
Spatial Patterns ◽  
Large Scale ◽  
Remotely Sensed ◽  
Host Population ◽  
Snail Host ◽  
Intermediate Hosts ◽  
National Scale ◽  
Temperature And Precipitation

The ecology of the aquatic snails that serve as obligatory intermediate hosts of human schistosomiasis is driven by climatic and hydrological factors which result in specific spatial patterns of occurrence and abundance. These patterns in turn affect, jointly with other determinants, the geography of the disease and the timing of transmission windows, with direct implications for the success of control and elimination programmes in the endemic countries. We address the spatial distribution of the intermediate hosts and their seasonal population dynamics within a predictive ecohydrological framework developed at the national scale for Burkina Faso, West Africa. The approach blends river network-wide information on hydrological ephemerality which conditions snail habitat suitability together with ensembles of discrete time ecological models forced by remotely sensed estimates of temperature and precipitation. The models were validated against up to four years of monthly snail abundance data. Simulations of model ensembles accounting for the uncertainty in remotely sensed products adequately reproduce observed snail demographic fluctuations observed in the field across habitat types, and produce national scale predictions by accounting for spatial patterns of hydrological conditions in the country. Geospatial estimates of seasonal snail abundance underpin large-scale, spatially explicit predictions of schistosomiasis incidence. This work can therefore contribute to the development of disease control and elimination programmes.

scholarly journals Redox regime shifts in microbially mediated biogeochemical cycles

2015 ◽  
Vol 12 (12) ◽  
pp. 3713-3724 ◽  
Author(s):  
T. Bush ◽  
I. B. Butler ◽  
A. Free ◽  
R. J. Allen
Keyword(s):  
Population Dynamics ◽  
Environmental Change ◽  
Microbial Population ◽  
Biogeochemical Cycles ◽  
Sulfur Cycle ◽  
Regime Shifts ◽  
Microbial Populations ◽  
Iron Cycling ◽  
Biogeochemical Models ◽  
Microbial Population Dynamics

Abstract. Understanding how the Earth's biogeochemical cycles respond to environmental change is a prerequisite for the prediction and mitigation of the effects of anthropogenic perturbations. Microbial populations mediate key steps in these cycles, yet they are often crudely represented in biogeochemical models. Here, we show that microbial population dynamics can qualitatively affect the response of biogeochemical cycles to environmental change. Using simple and generic mathematical models, we find that nutrient limitations on microbial population growth can lead to regime shifts, in which the redox state of a biogeochemical cycle changes dramatically as the availability of a redox-controlling species, such as oxygen or acetate, crosses a threshold (a "tipping point"). These redox regime shifts occur in parameter ranges that are relevant to the present-day sulfur cycle in the natural environment and the present-day nitrogen cycle in eutrophic terrestrial environments. These shifts may also have relevance to iron cycling in the iron-containing Proterozoic and Archean oceans. We show that redox regime shifts also occur in models with physically realistic modifications, such as additional terms, chemical states, or microbial populations. Our work reveals a possible new mechanism by which regime shifts can occur in nutrient-cycling ecosystems and biogeochemical cycles, and highlights the importance of considering microbial population dynamics in models of biogeochemical cycles.

scholarly journals The Accumulated Winter Season Severity Index (AWSSI)

2015 ◽  
Vol 54 (8) ◽  
pp. 1693-1712 ◽  
Author(s):  
Barbara E. Mayes Boustead ◽  
Steven D. Hilberg ◽  
Martha D. Shulski ◽  
Kenneth G. Hubbard
Keyword(s):  
Snow Depth ◽  
Meteorological Parameter ◽  
Winter Season ◽  
Weather Conditions ◽  
Severity Index ◽  
Winter Weather ◽  
Site Specific ◽  
Teleconnection Patterns ◽  
Temperature And Precipitation ◽  
Parallel Index

AbstractThe character of a winter can be defined by many of its features, including temperature averages and extremes, snowfall totals, snow depth, and the duration between onset and cessation of winter-weather conditions. The accumulated winter season severity index incorporates these elements into one site-specific value that defines the severity of a particular winter, especially when examined in the context of climatological values for that site. Thresholds of temperature, snowfall, and snow depth are assigned points that accumulate through the defined winter season; a parallel index uses temperature and precipitation to provide a snow proxy where snow data are unavailable or unreliable. The results can be analyzed like any other meteorological parameter to examine relationships to teleconnection patterns, determine trends, and create sector-specific applications, as well as to analyze an ongoing winter or any individual winter season to place its severity in context.

Evaluation of the actual evapotranspiration model of decomposition at a subalpine surface coal mine

1986 ◽  
Vol 64 (1) ◽  
pp. 35-38
Author(s):  
W. F. J. Parsons ◽  
D. M. Durall ◽  
D. Parkinson
Keyword(s):  
Dry Mass ◽  
Phleum Pratense ◽  
Decay Rates ◽  
Actual Evapotranspiration ◽  
Site Specific ◽  
Surface Coal Mine ◽  
Mass Losses ◽  
A Site ◽  
Phleum Pratense L ◽  
Single Exponential

Percentages of original dry mass lost annually and single exponential decay rates (k) for timothy (Phleum pratense L.) leaf litter decomposing on three reclaimed subalpine mine spoil plots (7, 3, and 1 years old) in Alberta, Canada, were compared with values predicted using generalized equations devised by Meentemeyer on the basis of an annual regional average of actual evapotranspiration (Thornthwaite) and a site-specific value (Christiansen). Measured decay rates on the more heavily vegetated plots (3 and 7 years old) were similar to k values predicted using Christiansen actual evapotranspiration values, while the decay rate on the plot with the least amount of vegetation cover (1 year old) was much greater than k values predicted using Christiansen or Thornthwaite actual evapotranspiration values. The actual evapotranspiration model severely underestimated annual percentage mass losses, regardless of whether Thornthwaite or Christiansen actual evapotranspiration values were used.

scholarly journals Seasonal Responses of Terrestrial Carbon Cycle to Climate Variations in CMIP5 Models: Evaluation and Projection

2017 ◽  
Vol 30 (16) ◽  
pp. 6481-6503 ◽  
Author(s):  
Yongwen Liu ◽  
Shilong Piao ◽  
Xu Lian ◽  
Philippe Ciais ◽  
W. Kolby Smith
Keyword(s):  
Temperature Sensitivity ◽  
Boreal Forests ◽  
Net Primary Production ◽  
Coupled Model ◽  
First Century ◽  
Cmip5 Models ◽  
Temperature And Precipitation ◽  
Northern High Latitude ◽  
Twenty First Century ◽  
Subarctic Ecosystems

Seventeen Earth system models (ESMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) were evaluated, focusing on the seasonal sensitivities of net biome production (NBP), net primary production (NPP), and heterotrophic respiration (Rh) to interannual variations in temperature and precipitation during 1982–2005 and their changes over the twenty-first century. Temperature sensitivity of NPP in ESMs was generally consistent across northern high-latitude biomes but significantly more negative for tropical and subtropical biomes relative to satellite-derived estimates. The temperature sensitivity of NBP in both inversion-based and ESM estimates was generally consistent in March–May (MAM) and September–November (SON) for tropical forests, semiarid ecosystems, and boreal forests. By contrast, for inversion-based NBP estimates, temperature sensitivity of NBP was nonsignificant for June–August (JJA) for all biomes except boreal forest; whereas, for ESM NBP estimates, the temperature sensitivity for JJA was significantly negative for all biomes except shrublands and subarctic ecosystems. Both satellite-derived NPP and inversion-based NBP are often decoupled from precipitation, whereas ESM NPP and NBP estimates are generally positively correlated with precipitation, suggesting that ESMs are oversensitive to precipitation. Over the twenty-first century, changes in temperature sensitivities of NPP, Rh, and NBP are consistent across all RCPs but stronger under more intensive scenarios. The temperature sensitivity of NBP was found to decrease in tropics and subtropics and increase in northern high latitudes in MAM due to an increased temperature sensitivity of NPP. Across all biomes, projected temperature sensitivity of NPP decreased in JJA and SON. Projected precipitation sensitivity of NBP did not change across biomes, except over grasslands in MAM.

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