scholarly journals Biased parasitoid sex ratios: Wolbachia, functional traits, local and landscape effects

2018 ◽  
Author(s):  
Zoltán László ◽  
Avar-Lehel Dénes ◽  
Lajos Király ◽  
Béla Tóthmérész
Keyword(s):  
Functional Traits ◽  
Large Scale ◽  
Mating Behaviour ◽  
Functional Trait ◽  
Landscape Scale ◽  
Landscape Composition ◽  
Habitat Amount ◽  
Explanatory Variables ◽  
Ovipositor Length ◽  
Adult Sex Ratio

AbstractAdult sex ratio (ASR) is a demographic key parameter, being essential for the survival and dynamics of a species populations. Biased ASR are adaptations to the environment on different scales, resulted by different mechanisms as inbreeding, mating behaviour, resource limitations, endosymbionts such as Wolbachia, and changes in density or spatial distribution. Parasitoid ASRs are also known to be strongly biased. But less information is available on large scale variable effects such as landscape composition or fragmentation. We aimed to study whether the landscape scale does affect the ASR of parasitoids belonging to the same tritrophic gall inducer community. We examined effects of characteristics on different scales as functional trait, local and landscape scale environment on parasitoid ASR. On species level ovipositor length, on local scale resource amount and density, while on landscape scale habitat amount, land use and landscape history were the examined explanatory variables. We controlled for the incidence and prevalence of Wolbachia infections. Parasitoid ASR is best explained by ovipositor length: with which increase ASR also increases; and available resource amount: with the gall diameter increase ASR decreases. On large scale the interaction of functional traits with habitat size also explained significantly the parasitoid ASRs. Our results support the hypothesis that large scale environmental characteristics affect parasitoid ASRs besides intrinsic and local characteristics.

scholarly journals The taxonomic and functional biogeographies of phytoplankton and zooplankton communities across boreal lakes

2018 ◽  
Author(s):  
Nicolas F. St-Gelais ◽  
Richard J. Vogt ◽  
Paul A. del Giorgio ◽  
Beatrix E. Beisner
Keyword(s):  
Water Quality ◽  
Functional Traits ◽  
Trophic Interactions ◽  
Large Scale ◽  
Dispersal Limitation ◽  
Fish Predation ◽  
Functional Trait ◽  
Boreal Lakes ◽  
Environmental Drivers ◽  
Biogeographical Distribution

AbstractStrong trophic interactions link primary producers (phytoplankton) and consumers (zooplankton) in lakes. However, the influence of such interactions on the biogeographical distribution of the taxa and functional traits of planktonic organisms in lakes has never been explicitly tested. To better understand the spatial distribution of these two major aquatic groups, we related the distributions of their taxa and functional traits across boreal lakes (104 for zooplankton and 48 for phytoplankton) to a common suite of environmental and spatial factors. We directly tested the degree of coupling in their taxonomic and functional distributions across the subset of common lakes. Phytoplankton functional composition responded mainly to properties related to water quality, while zooplankton composition responded more strongly to lake morphometry. Overall, the spatial distributions of phytoplankton and zooplankton were coupled at taxonomic and functional levels but after controlling for the effect of environmental drivers (water quality and morphometry) and dispersal limitation, no residual coupling could be attributed to trophic interactions. The lack of support for the role of trophic interactions as a driver coupling the distribution of plankton communities across boreal lakes indicates that taxon-specific and functional trait driven ecological interactions may not modulate large-scale spatial patterns of phytoplankton and zooplankton in a coordinated way. Our results point to community structuring forces beyond the phytoplankton-zooplankton trophic coupling itself, and which are specific to each trophic level: fish predation for zooplankton and resources for phytoplankton.

scholarly journals Linking functional traits and demography to model species-rich communities

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Loïc Chalmandrier ◽  
Florian Hartig ◽  
Daniel C. Laughlin ◽  
Heike Lischke ◽  
Maximilian Pichler ◽  
...  
Keyword(s):  
Functional Traits ◽  
Large Scale ◽  
Functional Trait ◽  
Ecological Systems ◽  
New Method ◽  
Volterra Model ◽  
Mountain Grassland ◽  
Species Abundances ◽  
Process Based Models

AbstractIt has long been anticipated that relating functional traits to species demography would be a cornerstone for achieving large-scale predictability of ecological systems. If such a relationship existed, species demography could be modeled only by measuring functional traits, transforming our ability to predict states and dynamics of species-rich communities with process-based community models. Here, we introduce a new method that links empirical functional traits with the demographic parameters of a process-based model by calibrating a transfer function through inverse modeling. As a case study, we parameterize a modified Lotka–Volterra model of a high-diversity mountain grassland with static plant community and functional trait data only. The calibrated trait–demography relationships are amenable to ecological interpretation, and lead to species abundances that fit well to the observed community structure. We conclude that our new method offers a general solution to bridge the divide between trait data and process-based models in species-rich ecosystems.

scholarly journals Reducing the Eltonian shortfall with trophic interaction models

2021 ◽  
Author(s):  
Dominique Caron ◽  
Luigi Maiorano ◽  
Wilfried Thuiller ◽  
Laura J. Pollock
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Functional Traits ◽  
Conservation Planning ◽  
Ecosystem Functioning ◽  
Species Interactions ◽  
Large Scale ◽  
Spatial Scales ◽  
Functional Trait ◽  
Predator Prey

While species interactions are fundamental for linking biodiversity to ecosystem functioning and for conservation, large-scale empirical data are lacking for most species and ecosystems. Accumulating evidence suggests that trophic interactions are predictable from available functional trait information, but we have yet to understand how well we can predict interactions across large spatial scales and food webs. Here, we built a model predicting predator-prey interactions based on functional traits for European vertebrates. We found that even models calibrated with very few known interactions (100 out of 71k) estimated the entire food web reasonably well. However, predators were easier to predict than prey, with prey in some clades being particularly difficult to predict (e.g., fowls and storks). Local food web connectance was also consistently over-estimated. Our results demonstrate the potential for filling gaps in sparse food webs, an important step towards a better description of biodiversity with strong implications for conservation planning.

Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

2021 ◽  
Author(s):  
Anna Schneider ◽  
Alexander Bonhage ◽  
Florian Hirsch ◽  
Alexandra Raab ◽  
Thomas Raab
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Large Scale ◽  
Soil Surface ◽  
Landscape Scale ◽  
Legacy Effects ◽  
Charcoal Production ◽  
Study Region ◽  
Land Use Legacies

<p>Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.</p><p>We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils. The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.</p>

Space Use and the Physical Attributes of Acute Care Units: A Quantitative Study

2021 ◽  
pp. 193758672110438
Author(s):  
David Kelly ◽  
Michael J. Pingel
Keyword(s):  
Acute Care ◽  
Quantitative Research ◽  
Large Scale ◽  
Space Use ◽  
Explanatory Variables ◽  
Significant Relationships ◽  
Physical Attributes ◽  
Floor Plans ◽  
Design Options ◽  
Station Location

This article shares the results of a quantitative analysis of the space use and physical attributes of 140 acute care units (ACU) completed since 2007. Objective: To fill a gap in the literature with respect to the state of practice for ACU design over the study period by investigating relationships among the physical characteristics and density of completed ACUs. Background: Robust industry interest about the topic—further agitated by the dearth of large-scale quantitative research regarding ACU space use—motivated completion of the study. Method: Through extraordinary collaboration by participating firms, floor plans of 140 new ACUs from the study period were gathered, systematically measured, and then analyzed. Results: Structural bay size, nurse station location, and the number of beds per unit were found to have significant relationships to ACU floor-gross area per bed. Additionally, nine significant associations among the explanatory variables were found, including moderate relationships among bay size, nurse station location, room handedness, and toilet room placement. Conclusion: The results suggest that project design teams tend to bundle key physical attributes together when planning ACUs. Moreover, density increases resulting from bay size reduction diminish as the bay size drops below 31′. Any impacts resulting from the major external events demarking the last decade were not sufficient to appreciably affect ACU density. Lastly, those concerned with increasing density and controlling ACU floor gross area are alerted to explore design options featuring bay sizes of approximately 30′ in conjunction with a centralized nursing model containing more than 32 beds per unit.

scholarly journals Variation Patterns of Functional Trait Moments Along Geographical Gradients and Their Environmental Determinants in the Subtropical Evergreen Broadleaved Forests

2021 ◽  
Vol 12 ◽  
Author(s):  
Caishuang Huang ◽  
Yue Xu ◽  
Runguo Zang
Keyword(s):  
Climate Variability ◽  
Leaf Area ◽  
Functional Traits ◽  
Specific Leaf Area ◽  
Functional Trait ◽  
Leaf Nitrogen ◽  
Subtropical Region ◽  
Mean Variance ◽  
Nitrogen Phosphorus ◽  
Skewness And Kurtosis

Understanding how environmental change alters the composition of plant assemblages is a major challenge in the face of global climate change. Researches accounting for site-specific trait values within forest communities help bridge plant economics theory and functional biogeography to better evaluate and predict relationships between environment and ecosystem functioning. Here, by measuring six functional traits (specific leaf area, leaf dry matter content, leaf nitrogen, and phosphorus concentration, leaf nitrogen/phosphorus, wood density) for 292 woody plant species (48,680 individuals) from 250 established permanent forest dynamics plots in five locations across the subtropical evergreen broadleaved forests (SEBLF) in China, we quantified functional compositions of communities by calculating four trait moments, i.e., community-weighted mean, variance, skewness, and kurtosis. The geographical (latitudinal, longitudinal, and elevational) patterns of functional trait moments and their environmental drivers were examined. Results showed that functional trait moments shifted significantly along the geographical gradients, and trait moments varied in different ways across different gradients. Plants generally showed coordinated trait shifts toward more conservative growth strategies (lower specific leaf area, leaf N and P concentration while higher leaf nitrogen/phosphorus and wood density) along increasing latitude and longitude. However, trends opposite to the latitudinal and longitudinal patterns appeared in trait mean values along elevation. The three sets of environmental variables (climate, soil and topography) explained 35.0–69.0%, 21.0–56.0%, 14.0–31.0%, and 16.0–30.0% of the variations in mean, variance, skewness, and kurtosis across the six functional traits, respectively. Patterns of shifts in functional trait moments along geographical gradients in the subtropical region were mainly determined by the joint effects of climatic and edaphic conditions. Climate regimes, especially climate variability, were the strongest driving force, followed by soil nutrients, while topography played the least role. Moreover, the relationship of variance, skewness and kurtosis with climate and their geographical patterns suggested that rare phenotypes at edges of trait space were selected in harsher environments. Our study suggested that environmental filtering (especially climate variability) was the dominant process of functional assembly for forest communities in the subtropical region along geographical gradients.

Beyond mean functional traits: Influence of functional trait profiles on forest structure, production, and mortality across the eastern US

2014 ◽  
Vol 328 ◽  
pp. 1-9 ◽  
Author(s):  
Matthew B. Russell ◽  
Christopher W. Woodall ◽  
Anthony W. D’Amato ◽  
Grant M. Domke ◽  
Sassan S. Saatchi
Keyword(s):  
Functional Traits ◽  
Forest Structure ◽  
Functional Trait

Network properties as functional traits for fungi

2021 ◽  
Author(s):  
Carlos Aguilar-Trigueros ◽  
Mark Fricker ◽  
Matthias Rillig
Keyword(s):  
Functional Traits ◽  
Interspecific Variation ◽  
Functional Trait ◽  
Ecological Strategies ◽  
Body Type ◽  
Network Growth ◽  
Transport Efficiency ◽  
Network Parameters ◽  
Phylogenetic Affiliation ◽  
Network Properties

<p>Fungal mycelia consist of an interconnected network of filamentous hyphae and represent the dominant phase of the lifecycle in all major fungal phyla, from basal to more recent clades. Indeed, the ecological success of fungi on land is partly due to such filamentous network growth. Nevertheless, fungal ecologists rarely use network features as functional traits. Given the widespread occurrence of this body type, we hypothesized that interspecific variation in network features may reflect both phylogenetic affiliation and distinct ecological strategies among species. We show first that there is high interspecific variation in network parameters of fungi, which partly correlates with taxonomy; and second that network parameters, related to predicted-mycelial transport mechanisms during the exploration phase, reveal the trait space in mycelium architecture across species.  This space predicts a continuum of ecological strategies along two extremes: from highly connected mycelia with high resilience to damage but limited transport efficiency, to poorly connected mycelia with low resilience but high transport efficiency. We argue that mycelial networks are potentially a rich source of information to inform functional trait analysis in fungi, but we also note the challenges in establishing common principles and processing pipelines that are required to facilitate widespread use of network properties as functional traits in fungal ecology.</p>

Landscape Influences on Stream Habitats and Biological Assemblages

2006 ◽  
Keyword(s):  
Landscape Scale ◽  
Riparian Zones ◽  
Total Abundance ◽  
Stream Channels ◽  
Urban Centers ◽  
Explanatory Variables ◽  
Agricultural Areas ◽  
Abundance And Distribution ◽  
Shallow Stream ◽  
Agricultural Regions

<em>Abstract.</em>—Wood is an important component of small to medium-sized streams in forested regions, but has been poorly studied in agricultural areas. Our goals were to (1) characterize the abundance, size, and distribution of wood in low-gradient streams in two agricultural regions, (2) quantify the influence of reach- and landscape-scale factors on the abundance and distribution of wood in these streams, and (3) compare trends across two study areas. Wood abundance was quantified in stream reaches in two diverse agricultural regions of the Midwestern United States: central Michigan and southeastern Minnesota. Wood abundance was quantified in 71 stream reaches, and an array of channel, riparian zone, and landscape features were characterized. Multiple regressions were conducted to predict abundance from those explanatory variables. We found that large wood was relatively scarce in these low-gradient streams compared to low-gradient streams in forested regions. Mean log size was greater, but total abundance was lower in Minnesota than Michigan. In Minnesota, greatest wood abundance and greatest extent of accumulations were predicted in wide, shallow stream channels with high substrate heterogeneity and woody riparian vegetation overhanging the channel. Models were dominated by reach-scale variables. In Michigan, largest densities of wood and accumulations were associated with catchments in hilly regions containing urban centers, with low soil water capacity, wide, shallow stream channels, low coarse particular organic matter standing stocks, and woody riparian zones. Models contained both reach- and landscape-scale variables. Difference in the extent of agricultural and forest land use/cover between Michigan and Minnesota may explain the differences in the models predicting wood variables. Patterns in wood abundance and distribution in these Midwestern streams differ from those observed in high gradient regions, and in low-gradient streams within forested regions. This has important implications for ecosystem processes and management of headwater streams in agricultural regions.

scholarly journals Statistical downscaling of a climate simulation of the last glacial cycle: temperature and precipitation over Northern Europe

2014 ◽  
Vol 10 (4) ◽  
pp. 1489-1500 ◽  
Author(s):  
N. Korhonen ◽  
A. Venäläinen ◽  
H. Seppä ◽  
H. Järvinen
Keyword(s):  
Large Scale ◽  
Climate Model ◽  
Ice Sheet ◽  
Additive Models ◽  
Northern Europe ◽  
Glacial Cycle ◽  
Explanatory Variables ◽  
Last Glacial ◽  
Temperature And Precipitation ◽  
The Last Glacial

Abstract. Earth system models of intermediate complexity (EMICs) have proven to be able to simulate the large-scale features of glacial–interglacial climate evolution. For many climatic applications the spatial resolution of the EMICs' output is, however, too coarse, and downscaling methods are needed. In this study we introduce a way to use generalized additive models (GAMs) for downscaling the large-scale output of an EMIC in very different climatological conditions ranging from glacial periods to current relatively warm climates. GAMs are regression models in which a combination of explanatory variables is related to the response through a sum of spline functions. We calibrated the GAMs using observations of the recent past climate and the results of short time-slice simulations of glacial climate performed by the relatively high-resolution general circulation model CCSM (Community Climate System Model) and the regional climate model RCA3 (Rossby Centre regional Atmospheric climate model). As explanatory variables we used the output of a simulation by the CLIMBER-2 (CLIMate and BiosphERe model 2) EMIC of the last glacial cycle, coupled with the SICOPOLIS (SImulation COde for POLythermal Ice Sheets) ice sheet model, i.e. the large-scale temperature and precipitation data of CLIMBER-2, and the elevation, distance to ice sheet, slope direction and slope angle from SICOPOLIS. The fitted GAMs were able to explain more than 96% of the temperature response with a correlation of >0.98 and more than 59% of the precipitation response with a correlation of >0.72. The first comparison with two pollen-based reconstructions of temperature for Northern Europe showed that CLIMBER-2 data downscaled by GAMs corresponded better with the reconstructions than did the bilinearly interpolated CLIMBER-2 surface temperature.

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