Intraspecific Trait Variability Determines Understorey Plant Community Assembly

2021 ◽  
Author(s):  
Piotr Olszewski ◽  
Radosław Puchałka ◽  
Piotr Sewerniak ◽  
Marcin Koprowski ◽  
Werner Ulrich
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Intraspecific Variability ◽  
Dry Mass ◽  
Soil Characteristics ◽  
Power Functions ◽  
Impatiens Parviflora ◽  
High Trait ◽  
Understorey Plants ◽  
Trait Variability

Abstract Increasing evidence points to the major impact of intraspecific variability in species characteristics on community assembly. Contrasting theories predict that high trait variability might either steepening dominance orders or promote diversity. Here, we try to test these predictions with understorey plants in a Polish mixed temperate forest. We focus on four important traits (leaf dry mass LDW, plant height SH, specific leaf area SLA, and number of flowers NF) of the small balsam Impatiens parviflora, the dominant species in this forest system. We relate trait variability to community species richness and abundances, as well as to soil characteristics. The variance – mean relationships of LDW, LH, and NF, but not of SLA, closely followed power functions with slopes > 1.5. Contrary to theory, abundances but not species richness of non-I. parviflora species significantly decreased within increasing variance in I. parviflora trait expression. High trait variability prevailed a higher species richness. Trait variability did not significantly influence species composition and was not significantly correlated with soil characteristics. Our results emphasis the need to study trait variability in terms of appropriate statistical standards as provided by the allometric variance - mean relationship. We argue that an individual based study of local trait variability might return important insights into the composition and assembly of local communities.

scholarly journals Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

2021 ◽  
Vol 13 (14) ◽  
pp. 7737
Author(s):  
Amin Soltani ◽  
Mahdieh Azimi ◽  
Brendan C. O’Kelly
Keyword(s):  
Energy Levels ◽  
Model Development ◽  
Dry Mass ◽  
Unit Weight ◽  
Power Functions ◽  
Compaction Characteristics ◽  
Practical Applications ◽  
Fine Grained ◽  
Practical Procedure ◽  
Fine Grained Soil

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

From Forest to Farmland: Species Richness Patterns of Trees and Understorey Plants along a Gradient of Forest Conversion in Southwestern Cameroon

2006 ◽  
Vol 15 (13) ◽  
pp. 4097-4117 ◽  
Author(s):  
K. Serge Bobo ◽  
Matthias Waltert ◽  
N. Moses Sainge ◽  
John Njokagbor ◽  
Heleen Fermon ◽  
...  
Keyword(s):  
Species Richness ◽  
Forest Conversion ◽  
Richness Patterns ◽  
Understorey Plants

scholarly journals Phenotypic plasticity can reverse the relative extent of intra- and interspecific variability across a thermal gradient

2021 ◽  
Vol 288 (1953) ◽  
pp. 20210428
Author(s):  
Staffan Jacob ◽  
Delphine Legrand
Keyword(s):  
Phenotypic Plasticity ◽  
Thermal Gradient ◽  
Environmental Gradients ◽  
Intraspecific Variability ◽  
Functional Trait ◽  
Ecosystem Functions ◽  
Interspecific Variability ◽  
Ciliate Species ◽  
Relative Extent ◽  
Trait Variability

Intra- and interspecific variability can both ensure ecosystem functions. Generalizing the effects of individual and species assemblages requires understanding how much within and between species trait variation is genetically based or results from phenotypic plasticity. Phenotypic plasticity can indeed lead to rapid and important changes of trait distributions, and in turn community functionality, depending on environmental conditions, which raises a crucial question: could phenotypic plasticity modify the relative importance of intra- and interspecific variability along environmental gradients? We quantified the fundamental niche of five genotypes in monocultures for each of five ciliate species along a wide thermal gradient in standardized conditions to assess the importance of phenotypic plasticity for the level of intraspecific variability compared to differences between species. We showed that phenotypic plasticity strongly influences trait variability and reverses the relative extent of intra- and interspecific variability along the thermal gradient. Our results show that phenotypic plasticity may lead to either increase or decrease of functional trait variability along environmental gradients, making intra- and interspecific variability highly dynamic components of ecological systems.

scholarly journals Intraspecific trait variability of trees is related to canopy species richness in European forests

2019 ◽  
Vol 36 ◽  
pp. 24-32 ◽  
Author(s):  
Raquel Benavides ◽  
Fernando Valladares ◽  
Christian Wirth ◽  
Sandra Müller ◽  
Michael Scherer-Lorenzen
Keyword(s):  
Species Richness ◽  
European Forests ◽  
Intraspecific Trait Variability ◽  
Canopy Species ◽  
Trait Variability

Seasonality, species richness and poor dispersion mediate intraspecific trait variability in stonefly community responses along an elevational gradient

2017 ◽  
Vol 62 (5) ◽  
pp. 916-928 ◽  
Author(s):  
Aina Garcia-Raventós ◽  
Aida Viza ◽  
José M. Tierno de Figueroa ◽  
Joan L. Riera ◽  
Cesc Múrria
Keyword(s):  
Species Richness ◽  
Elevational Gradient ◽  
Community Responses ◽  
Intraspecific Trait Variability ◽  
Trait Variability

scholarly journals Disentangling the relative importance of species occurrence, abundance and intraspecific variability in community assembly: a trait-based approach at the whole-plant level in Mediterranean forests

Oikos ◽  
2015 ◽  
Vol 125 (3) ◽  
pp. 354-363 ◽  
Author(s):  
Enrique G. de la Riva ◽  
Ignacio M. Pérez-Ramos ◽  
Ambra Tosto ◽  
Carmen M. Navarro-Fernández ◽  
Manuel Olmo ◽  
...  
Keyword(s):  
Community Assembly ◽  
Intraspecific Variability ◽  
Mediterranean Forests ◽  
Relative Importance ◽  
Species Occurrence ◽  
Whole Plant ◽  
Plant Level

scholarly journals Exotic earthworm (Oligochaeta: Lumbricidae) assemblages on a landscape scale in central Canadian woodlands: importance of region and vegetation type

2017 ◽  
Vol 47 (7) ◽  
pp. 935-945 ◽  
Author(s):  
Amy Choi ◽  
Tara E. Sackett ◽  
Sandy M. Smith ◽  
M. Isabel Bellocq
Keyword(s):  
Species Richness ◽  
Forest Restoration ◽  
Vegetation Type ◽  
Mixed Forest ◽  
Habitat Type ◽  
Soil Characteristics ◽  
Landscape Scale ◽  
Assemblage Composition ◽  
Earthworm Species ◽  
South Central

A growing understanding about the impacts of earthworms (Oligochaeta: Lumbricidae) on ecosystem processes and forest restoration necessitates an examination of their role in Canadian forests where they have become invasive. Little is known about the landscape-scale responses of earthworm populations to different regional characteristics and vegetation types within Canada’s central woodlands. We examined the regional variation of earthworm species richness, biomass, and assemblage composition across a range of four municipal regions (from south to north: Halton, Wellington, York, and Simcoe) and four habitat types (deciduous forest, mixed forest, tree plantation, and meadow) with varying soil characteristics in woodlands of south-central Ontario, Canada. In general, earthworm communities differed by region but not by habitat type. The most southern regions supported the highest earthworm species richness, biomass (i.e., Lumbricus and Octolasion), and density, and this was associated with a south–north gradient in soil characteristics. Assemblage composition differed by region but not by habitat type. The observed south–north gradient suggests an underlying effect of invasion spread associated with human settlement and density. Our results provide baseline information about earthworm communities in south-central Ontario forests and will enable managers to plan for the increasing role of earthworms in Canada’s future forests.

scholarly journals Chemical Similarity of Co-occurring Trees Decreases With Precipitation and Temperature in North American Forests

2021 ◽  
Author(s):  
Brian E Sedio ◽  
Marko J Spasojevic ◽  
Jonathan A Myers ◽  
S Joseph Wright ◽  
Maria D Person ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Wood Density ◽  
Plant Diversity ◽  
Community Assembly ◽  
Seed Mass ◽  
Biotic Interactions ◽  
Morphological Trait ◽  
Chemical Similarity ◽  
Precipitation And Temperature

Plant diversity varies immensely over large-scale gradients in temperature, precipitation, and seasonality at global and regional scales. This relationship may be driven in part by climatic variation in the relative importance of abiotic and biotic interactions to the diversity and composition of plant communities. In particular, biotic interactions may become stronger and more host specific with increasing precipitation and temperature, resulting in greater plant species richness in wetter and warmer environments. This hypothesis predicts that the many defensive compounds found in plants’ metabolomes should increase in richness and decrease in interspecific similarity with precipitation, temperature, and plant diversity. To test this prediction, we compared patterns of chemical and morphological trait diversity of 140 woody plant species among seven temperate forests in North America representing 16.2°C variation in mean annual temperature (MAT), 2,115 mm variation in mean annual precipitation (MAP), and from 10 to 68 co-occurring species. We used untargeted metabolomics methods based on data generated with liquid chromatography-tandem mass spectrometry to identify, classify, and compare 13,480 unique foliar metabolites and to quantify the metabolomic similarity of species in each community with respect to the whole metabolome and each of five broad classes of metabolites. In addition, we compiled morphological trait data from existing databases and field surveys for three commonly measured traits (specific leaf area [SLA], wood density, and seed mass) for comparison with foliar metabolomes. We found that chemical defense strategies and growth and allocation strategies reflected by these traits largely represented orthogonal axes of variation. In addition, functional dispersion of SLA increased with MAP, whereas functional richness of wood density and seed mass increased with MAT. In contrast, chemical similarity of co-occurring species decreased with both MAT and MAP, and metabolite richness increased with MAT. Variation in metabolite richness among communities was positively correlated with species richness, but variation in mean chemical similarity was not. Our results are consistent with the hypothesis that plant metabolomes play a more important role in community assembly in wetter and warmer climates, even at temperate latitudes, and suggest that metabolomic traits can provide unique insight to studies of trait-based community assembly.

scholarly journals Species Diversity and Community Assembly of Cladocera in the Sand Ponds of the Ulan Buh Desert, Inner Mongolia of China

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 502
Author(s):  
Yang-Liang Gu ◽  
Qi Huang ◽  
Lei Xu ◽  
Eric Zeus Rizo ◽  
Miguel Alonso ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Community Assembly ◽  
Inner Mongolia ◽  
Regression Tree ◽  
Environmental Variable ◽  
Classification And Regression Tree ◽  
Tree Model ◽  
Environmental Selection ◽  
Ulan Buh Desert

In deserts, pond cladocerans suffer harsh conditions like low and erratic rainfall, high evaporation, and highly variable salinity, and they have limited species richness. The limited species can take advantage of ephippia or resting eggs for being dispersed with winds in such habitats. Thus, environmental selection is assumed to play a major role in community assembly, especially at a fine spatial scale. Located in Inner Mongolia, the Ulan Buh desert has plenty of temporary water bodies and a few permanent lakes filled by groundwater. To determine species diversity and the role of environmental selection in community assembly in such a harsh environment, we sampled 37 sand ponds in June 2012. Fourteen species of Cladocera were found in total, including six pelagic species, eight littoral species, and two benthic species. These cladocerans were mainly temperate and cosmopolitan fauna. Our classification and regression tree model showed that conductivity, dissolved oxygen, and pH were the main factors correlated with species richness in the sand ponds. Spatial analysis using a PCNM model demonstrated a broad-scale spatial structure in the cladoceran communities. Conductivity was the most significant environmental variable explaining cladoceran community variation. Two species, Moina cf. brachiata and Ceriodaphnia reticulata occurred commonly, with an overlap at intermediate conductivity. Our results, therefore, support that environmental selection plays a major role in structuring cladoceran communities in deserts.

scholarly journals Environmental Filtering Influences Functional Community Assembly of Epibenthic Communities

2021 ◽  
Vol 8 ◽  
Author(s):  
Lauren Sutton ◽  
Franz J. Mueter ◽  
Bodil A. Bluhm ◽  
Katrin Iken
Keyword(s):  
Community Assembly ◽  
Chukchi Sea ◽  
Environmental Filtering ◽  
Biotic Interactions ◽  
Beaufort Sea ◽  
Functional Trait ◽  
Functional Community ◽  
Trait Convergence ◽  
High Trait ◽  
Epibenthic Communities

Community assembly theory states that species assemble non-randomly as a result of dispersal limitation, biotic interactions, and environmental filtering. Strong environmental filtering likely leads to local assemblages that are similar in their functional trait composition (high trait convergence) while functional trait composition will be less similar (high trait divergence) under weaker environmental filters. We used two Arctic shelves as case studies to examine the relationship between functional community assembly and environmental filtering using the geographically close but functionally and environmentally dissimilar epibenthic communities on the Chukchi and Beaufort Sea shelves. Environmental drivers were compared to functional trait composition and to trait convergence within each shelf. Functional composition in the Chukchi Sea was more strongly correlated with environmental gradients compared to the Beaufort Sea, as shown by a combination of RLQ and fourth corner analyses and community-weighted mean redundancy analyses. In the Chukchi Sea, epibenthic functional composition, particularly body size, reproductive strategy, and several behavioral traits (i.e., feeding habit, living habit, movement), was most strongly related to gradients in percent mud and temperature while body size and larval development were most strongly related to a depth gradient in the Beaufort Sea. The stronger environmental filter in the Chukchi Sea also supported the hypothesized relationship with higher trait convergence, although this relationship was only evident at one end of the observed environmental gradient. Strong environmental filtering generally provides a challenge for biota and can be a barrier for invading species, a growing concern for the Chukchi Sea shelf communities under warming conditions. Weaker environmental filtering, such as on the Beaufort Sea shelf, generally leads to communities that are more structured by biotic interactions, and possibly representing partitioning of resources among species from intermediate disturbance levels. We provide evidence that environmental filtering can structure functional community composition, providing a baseline of how community function could be affected by stressors such as changes in environmental conditions or increased anthropogenic disturbance.

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