scholarly journals Genotypic variation in a foundation tree ( Populus tremula L.) explains community structure of associated epiphytes

2014 ◽  
Vol 10 (4) ◽  
pp. 20140190 ◽  
Author(s):  
Chantel Davies ◽  
Christopher J. Ellis ◽  
Glenn R. Iason ◽  
Richard A. Ennos
Keyword(s):  
Community Structure ◽  
Environmental Conditions ◽  
Spatial Scales ◽  
Genotypic Variation ◽  
Genotypic Diversity ◽  
Environmental Variation ◽  
Populus Tremula ◽  
Foundation Species ◽  
Community Genetics ◽  
Epiphyte Community

Community genetics hypothesizes that within a foundation species, the genotype of an individual significantly influences the assemblage of dependent organisms. To assess whether these intra-specific genetic effects are ecologically important, it is required to compare their impact on dependent organisms with that attributable to environmental variation experienced over relevant spatial scales. We assessed bark epiphytes on 27 aspen ( Populus tremula L.) genotypes grown in a randomized experimental array at two contrasting sites spanning the environmental conditions from which the aspen genotypes were collected. We found that variation in aspen genotype significantly influenced bark epiphyte community composition, and to the same degree as environmental variation between the test sites. We conclude that maintaining genotypic diversity of foundation species may be crucial for conservation of associated biodiversity.

scholarly journals Growing up aspen: ontogeny and trade-offs shape growth, defence and reproduction in a foundation species

2020 ◽  
Author(s):  
Christopher T Cole ◽  
Clay J Morrow ◽  
Hilary L Barker ◽  
Kennedy F Rubert-Nason ◽  
Jennifer F L Riehl ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Genotypic Variation ◽  
Chemical Defence ◽  
Extrafloral Nectaries ◽  
Foundation Species ◽  
Community Genetics ◽  
Indirect Defence ◽  
Juvenile Period ◽  
Trade Offs ◽  
Sex Marker

Abstract Background and Aims Intraspecific variation in foundation species of forest ecosystems can shape community and ecosystem properties, particularly when that variation has a genetic basis. Traits mediating interactions with other species are predicted by simple allocation models to follow ontogenetic patterns that are rarely studied in trees. The aim of this research was to identify the roles of genotype, ontogeny and genotypic trade-offs shaping growth, defence and reproduction in aspen. Methods We established a common garden replicating >500 aspen genets in Wisconsin, USA. Trees were measured through the juvenile period into the onset of reproduction, for growth, defence chemistry (phenolic glycosides and condensed tannins), nitrogen, extrafloral nectaries, leaf morphology (specific leaf area), flower production and foliar herbivory and disease. We also assayed the TOZ19 sex marker and heterozygosity at ten microsatellite loci. Key Results We found high levels of genotypic variation for all traits, and high heritabilities for both the traits and their ontogenetic trajectories. Ontogeny strongly shaped intraspecific variation, and trade-offs among growth, defence and reproduction supported some predictions while contradicting others. Both direct resistance (chemical defence) and indirect defence (extrafloral nectaries) declined during the juvenile stage, prior to the onset of reproduction. Reproduction was higher in trees that were larger, male and had higher individual heterozygosity. Growth was diminished by genotypic allocation to both direct and indirect defence as well as to reproduction, but we found no evidence of trade-offs between defence and reproduction. Conclusions Key traits affecting the ecological communities of aspen have high levels of genotypic variation and heritability, strong patterns of ontogeny and clear trade-offs among growth, defence and reproduction. The architecture of aspen’s community genetics – its ontogeny, trade-offs and especially its great variability – is shaped by both its broad range and the diverse community of associates, and in turn further fosters that diversity.

scholarly journals Plant genotypic diversity increases population size of a herbivorous insect

2011 ◽  
Vol 278 (1721) ◽  
pp. 3108-3115 ◽  
Author(s):  
Shunsuke Utsumi ◽  
Yoshino Ando ◽  
Timothy P. Craig ◽  
Takayuki Ohgushi
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Natural Enemy ◽  
Genotypic Variation ◽  
Genotypic Diversity ◽  
Community Genetics ◽  
Aphid Population ◽  
Herbivorous Insect ◽  
Mixed Genotype ◽  
The Impact

It is critical to incorporate the process of population dynamics into community genetics studies to identify the mechanisms of the linkage between host plant genetics and associated communities. We studied the effects of plant genotypic diversity of tall goldenrod Solidago altissima on the population dynamics of the aphid Uroleucon nigrotuberculatum . We found genotypic variation in plant resistance to the aphid in our experiments. To determine the impact of plant genotypic diversity on aphid population dynamics, we compared aphid densities under conditions of three treatments: single-genotype plots, mixed-genotype plots and mixed-genotype-with-cages plots. In the latter treatment plants were individually caged to prevent natural enemy attack and aphid movement among plants. The synergistic effects of genotypes on population size were demonstrated by the greater aphid population size in the mixed-genotype treatment than expected from additive effects alone. Two non-exclusive hypotheses are proposed to explain this pattern. First, there is a source–sink relationship among plant genotypes: aphids move from plant genotypes where their reproduction is high to genotypes where their reproduction is low. Second, natural enemy mortality is reduced in mixed plots in a matrix of diverse plant genotypes.

Seasonal and annual genotypic variation and the effect of climate on population genetic structure of the cereal aphid Sitobion avenae in northern France

2007 ◽  
Vol 98 (2) ◽  
pp. 159-168 ◽  
Author(s):  
C.-A. Dedryver ◽  
J.-F. Le Gallic ◽  
L. Haack ◽  
F. Halkett ◽  
Y. Outreman ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Spatial Scales ◽  
Genotypic Variation ◽  
Reproductive Mode ◽  
Genotypic Diversity ◽  
Theoretical Models ◽  
Sitobion Avenae ◽  
Cereal Aphid ◽  
Northern France ◽  
High Dispersal

AbstractChanges in the genetic structure and genotypic variation of the aphid Sitobion avenae collected from cereal crops in northern France were examined by analysing variation at five microsatellite loci across several years and seasons. Little regional and temporal differentiation was detected, as shown by very low FST among populations. Repeated genotypes, significant heterozygote deficits, positive FIS values and frequent linkage disequilibria were found in nearly all samples, suggesting an overall pattern of reproductive mode variation in S. avenae populations. In addition, samples from Brittany (Bretagne) showed greater signs of asexual reproduction than those from the north of France, indicating a trend toward increasing sexuality northward. These patterns of reproductive variation in S. avenae are consistent with theoretical models of selection of aphid reproductive modes by climate. Contrasting with little changes in allelic frequencies, genotypic composition varied substantially in time and, to a lesser extent, in space. An important part of changes in genotypic arrays was due to the variation in frequency distribution of common genotypes, i.e. those that were found at several instances in the samples. Genotypic composition was also shown to vary according to climate, as genotypic diversity in spring was significantly correlated with the severity of the previous winter and autumn. We propose that the genetic homogeneity among S. avenae populations shown here across large temporal and spatial scales is the result of two forces: (i) migration conferred by high dispersal capabilities, and (ii) selection over millions of hectares of cereals (mostly wheat) bred from a narrow genetic base.

scholarly journals Scaling up biodiversity ecosystem functioning relationships: the role of environmental variability in space and time

2020 ◽  
Author(s):  
Patrick L. Thompson ◽  
Sonia Kéfi ◽  
Yuval R. Zelnik ◽  
Laura E. Dee ◽  
Shaopeng Wang ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Ecosystem Functioning ◽  
Community Dynamics ◽  
Environmental Variability ◽  
Formal Model ◽  
Spatial Scales ◽  
Environmental Variation ◽  
Scale Dependence ◽  
Temporal Scale ◽  
Number Of Species

AbstractThe biodiversity and ecosystem functioning (BEF) relationship is expected to depend on the spatial or temporal scale at which it is measured. Environmental variation is hypothesized to explain this scale dependence because it influences how quickly biodiversity accumulates with scale. However, this link has yet to be demonstrated in a formal model. Here we use a Lotka-Volterra competition model to simulate community dynamics when environmental conditions vary across either space or time. Species differ in their optimal environmental conditions, which results in turnover in community composition. We vary biodiversity by modelling communities with different sized regional species pools and ask how the amount of biomass per unit area depends on the number of species present, and the spatial or temporal scale at which it is measured. We find that more biodiversity is required to maintain functioning at larger temporal and spatial scales. The number of species required increases quickly when environmental autocorrelation is low, and slowly when autocorrelation is high. Both spatial and temporal environmental variation led to scale dependence in BEF, but autocorrelation had larger impacts when environmental change was temporal. These findings show how the biodiversity required to maintain functioning is expected to increase over time and space.

scholarly journals Macrosystem community assembly patterns are predicted by foundation tree species genetic connectivity and environment across the American Southwest

2021 ◽  
Author(s):  
Helen M. Bothwell ◽  
Arthur R. Keith ◽  
Julia B. Hull ◽  
Hillary F. Cooper ◽  
Lela V. Andrews ◽  
...  
Keyword(s):  
Community Structure ◽  
Community Assembly ◽  
Tree Species ◽  
Fungal Endophytes ◽  
Environmental Variation ◽  
American Southwest ◽  
Community Genetics ◽  
Genetic Connectivity ◽  
Genetic Management ◽  
Environmental Distance

Macrosystems ecology is an emerging science that aims to integrate traditionally distinct disciplines to predict how hierarchical interacting processes influence the emergence of complex patterns across local to regional and global scales. Despite increased focus on cross-scale relationships and cross-disciplinary integration, few macroecology studies incorporate genetic-based processes. Here we used a community genetics approach to investigate the pattern-process relationships underlying the emergence of macroscale biodiversity patterns. We tested the hypothesis that environmental variation, geography, and genetic connectivity in a foundation tree species differentially predict associated community assembly patterns from local to continental scales. Using genome-wide SNP data, we assessed genetic connectivity as a function of genetic similarity and structure in Fremont cottonwood (Populus fremontii) across its distribution throughout the southwestern US and México. For the same trees, we measured community composition, diversity, and abundance of leaf modifying arthropods and sequenced targeted amplicons of twig fungal endophytes. Five key findings emerged. (1) We identified three primary and six secondary population genetic groups within P. fremontii, which occupy distinct climate niches. (2) Both the leaf modifying arthropod and fungal endophyte communities were significantly differentiated across host tree ecotypes, with genetic distance among sampling locations explaining 13-17% of respective macroscale community structure. (3) For arthropods, environmental distance was the strongest driver of community similarity. (4) Conversely, host genetic connectivity was the most important contributor to macroscale endophyte community structure, with no significant contribution of environmental distance. (5) Furthermore, we observed a shift in the strength of interspecific relationships, with host genetics most strongly influencing associated communities at the intermediate population scale. Our findings suggest that genetic connectivity and environmental variation play integrated roles in macroscale community assembly, and their relative importance changes with scale. Thus, conservation genetic management of the diversity harbored within foundation species is vital for sustaining associated regional biodiversity.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

scholarly journals The Impact of Different Environmental Conditions during Vegetative Propagation on Growth, Survival, and Biochemical Characteristics in Populus Hybrids in Clonal Field Trial

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 892
Author(s):  
Valda Gudynaitė-Franckevičienė ◽  
Alfas Pliūra
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Environmental Conditions ◽  
Vegetative Propagation ◽  
Genotypic Variation ◽  
Hybrid Poplar ◽  
Field Trials ◽  
Biochemical Traits ◽  
Suburban Areas ◽  
Growing Conditions

To have a cleaner environment, good well-being, and improve the health of citizens it is necessary to expand green urban and suburban areas using productive and adapted material of tree species. The quality of urban greenery, resistance to negative climate change factors and pollution, as well as efficiency of short-rotation forestry in suburban areas, depends primarily on the selection of hybrids and clones, suitable for the local environmental conditions. We postulate that ecogenetic response, phenotypic plasticity, and genotypic variation of hybrid poplars (Populus L.) grown in plantations are affected not only by the peculiarities of hybrids and clones, but also by environmental conditions of their vegetative propagation. The aim of the present study was to estimate growth and biochemical responses, the phenotypic plasticity, genotypic variation of adaptive traits, and genetically regulated adaptability of Populus hybrids in field trials which may be predisposed by the simulated contrasting temperature conditions at their vegetative propagation phase. The research was performed with the 20 cultivars and experimental clones of one intraspecific cross and four different interspecific hybrids of poplars propagated under six contrasting temperature regimes in phytotron. The results suggest that certain environmental conditions during vegetative propagation not only have a short-term effect on tree viability and growth, but also can help to adapt to climate change conditions and grow successfully in the long-term. It was found that tree growth and biochemical traits (the chlorophyll A and B, pigments content and the chlorophyll A/B ratio) of hybrid poplar clones grown in field trials, as well as their traits’ genetic parameters, were affected by the rooting-growing conditions during vegetative propagation phase. Hybrids P. balsamifera × P. trichocarpa, and P. trichocarpa × P. trichocarpa have shown the most substantial changes of biochemical traits across vegetative propagation treatments in field trial. Rooting-growing conditions during vegetative propagation had also an impact on coefficients of genotypic variation and heritability in hybrid poplar clones when grown in field trials.

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