Plant subindividual functional diversity and carbon cycling.

Plant subindividual trait variation is a neglected level of functional diversity that contributes to the variation of phenotypes and ecological communities. Disregarding the role of subindividual functional diversity (SFD) in nature may lead to incorrect understanding of spatial and temporal scales of relationships between trait diversity, ecosystem function, and carbon cycling.

Ten simple rules for a mom-friendly Academia.

Women (and all gender-discriminated people) are underrepresented in science, especially in leadership positions and higher stages of the scientific career. One of the main causes of career abandonment by women is maternity, with many women leaving Academia after having their first child because of the career penalties associated with motherhood. Thus, more actions to help scientific moms to balance family and academic work are urgently needed to increase representation of women and other gender discriminated people in Academia. Besides mothers, these rules may also benefit other groups such as mothers-to-be, fathers, caregivers, and women in general. Increasing women representation in science, including mothers, is critical because equality is a fundamental right, and because more diverse working environments are more productive and get to more optimal solutions. Here, we describe 10 simple rules that can be adopted in Academia to halt the abandonment of scientific careers by women after motherhood. We strongly encourage their implementation to increase gender diversity and equality in science.

Mammal traits and soil biogeochemistry: Functional diversity relates to composition of soil organic matter.

Mammal diversity affects carbon concentration in Amazonian soils. It is known that some species traits determine carbon accumulation in organisms (e.g., size and longevity), and are also related to feeding strategies, thus linking species traits to the type of organic remains that are incorporated into the soil. Trait diversity in mammal assemblages - that is, its functional diversity - may therefore constitute another mechanism linking biodiversity to soil organic matter (SOM) accumulation. To address this hypothesis, we analyzed across 83 mammal assemblages in the Amazon biome (Guyana), the elemental (by ED-XRF and CNH analysis) and molecular (FTIR-ATR) composition of SOM of topsoils (401 samples) and trait diversity (functional richness, evenness, and divergence) for each mammal assemblage. Lower mammal functional richness but higher functional divergence were related to higher content of carbonyl and aliphatic SOM, potentially affecting SOM recalcitrance. Our results might allow the design of biodiversity management plans that consider the effect of mammal traits on carbon sequestration and accumulation in soils.

Trait diversity shapes the carbon cycle.

Trait evolution is shaped by carbon economics at the organismal level. Here, we expand this idea to the ecosystem level and show how the trait diversity of ecological communities influences the carbon cycle. Systematic shifts in trait diversity will likely trigger changes in the carbon cycle.

Mammal and tree diversity accumulate different types of soil organic matter in the northern Amazon.

Diversity of plants and animals influence soil carbon through their contributions to soil organic matter (SOM). However, we do not know whether mammal and tree communities affect SOM composition in the same manner. This question is relevant because not all forms of carbon are equally resistant to mineralization by microbes and thus, relevant to carbon storage. We analyzed the elemental and molecular composition of 401 soil samples, with relation to the species richness of 83 mammal and tree communities at a landscape scale across 4.8 million hectares in the northern Amazon. We found opposite effects of mammal and tree richness over SOM composition. Mammal diversity is related to SOM rich in nitrogen, sulfur and iron whereas tree diversity is related to SOM rich in aliphatic and carbonyl compounds. These results help us to better understand the role of biodiversity in the carbon cycle and its implications for climate change mitigation.

Epigenetic and Phenotypic Responses to Experimental Climate Change of Native and Invasive Carpobrotus edulis.

Despite the recent discoveries on how DNA methylation could help plants to adapt to changing environments, the relationship between epigenetics and climate change or invasion in new areas is still poorly known. Here, we investigated, through a field experiment, how the new expected climate scenarios for Southern Europe, i.e., increased temperature and decreased rainfall, might affect global DNA methylation in relation to phenotypic variation in individuals of clonal plant, Carpobrotus edulis, from its native (Southern African) and invaded (northwestern Iberian Peninsula) area. Our results showed that changes in temperature and rainfall induced phenotypic but not global DNA methylation differences among plants, and the climatic effects were similar for plants coming from the native or invaded areas. The individuals from the Iberian Peninsula showed higher levels of global methylation than their native counterparts from South Africa. We also observed differences between natives and invasive phenotypes in traits related to the pattern of biomass partitioning and to the strategies for water uptake and use and found an epigenetic contribution to phenotypic changes in some leaf traits, especially on the nitrogen isotopic composition. We conclude that the increased temperature and decreased rainfall projected for Southern Europe during the course of the twenty-first century may foster phenotypic changes in C. edulis, possibly endowing this species with a higher ability to successful cope the rapid environmental shifts. The epigenetic and phenotypic divergence that we observed between native and invasive plants suggests an intraspecific functional variation during the process of invasion. This result could indicate that phenotypic plasticity and global DNA methylation are related to the colonization of new habitats. Our findings reinforce the importance of epigenetic plasticity on rapid adaptation of invasive clonal plants.

Phenotypic, epigenetic, and fitness diversity within plant genotypes.

Plant plastic responses to environmental variation, at scales smaller than the individual plant size, promote phenotypic and epigenetic diversity among repeated structures within genotypes. Different epigenetic marks in the somatic line can translate to the germline and seeds, generating a fitness patchwork in the progeny with unexplored effects on plant evolutionary dynamics.

Phenotypic plasticity in plant defense across life stages: Inducibility, transgenerational induction, and transgenerational priming in wild radish.

As they develop, many plants deploy shifts in antiherbivore defense allocation due to changing costs and benefits of their defensive traits. Plant defenses are known to be primed or directly induced by herbivore damage within generations and across generations by long-lasting epigenetic mechanisms. However, little is known about the differences between life stages of epigenetically inducible defensive traits across generations. To help fill this knowledge gap, we conducted a multigenerational experiment to determine whether defense induction in wild radish plants was reflected in chromatin modifications (DNA methylation); we then examined differences between seedlings and reproductive plants in current and transgenerational plasticity in chemical (glucosinolates) and physical (trichomes) defenses in this species. Herbivory triggered genome methylation both in targeted plants and their offspring. Within one generation, both defenses were highly inducible at the seedling stage, but only chemical defenses were inducible in reproductive plants. Across generations, herbivory experienced by mother plants caused strong direct induction of physical defenses in their progeny, with effects lasting from seedling to reproductive stages. For chemical defenses, however, this transgenerational induction was evident only in adults. Transgenerational priming was observed in physical and chemical defenses, particularly in adult plants. Our results show that transgenerational plasticity in plant defenses in response to herbivore offense differs for physical and chemical defense and changes across plant life stages.

All Traits Are Functional: An Evolutionary Viewpoint.

There is increasing confusion regarding the term 'functional trait' and its links with ecosystem functioning. Functional traits are defined as traits that affect individual fitness. I use an evolutionary rationale that considers the integration of the phenotype, the environmental variation, and the relationship between both, to propose that all traits are functional.

Transgenerational Plasticity in Flower Color Induced by Caterpillars.

Variation in flower color due to transgenerational plasticity could stem directly from abiotic or biotic environmental conditions. Finding a link between biotic ecological interactions across generations and plasticity in flower color would indicate that transgenerational effects of ecological interactions, such as herbivory, might be involved in flower color evolution. We conducted controlled experiments across four generations of wild radish (Raphanus sativus, Brassicaceae) plants to explore whether flower color is influenced by herbivory, and to determine whether flower color is associated with transgenerational chromatin modifications. We found transgenerational effects of herbivory on flower color, partly related to chromatin modifications. Given the presence of herbivory in plant populations worldwide, our results are of broad significance and contribute to our understanding of flower color evolution.

Mammal diversity influences the carbon cycle through trophic interactions in the Amazon.

Biodiversity affects many ecosystem functions and services, including carbon cycling and retention. While it is known that the efficiency of carbon capture and biomass production by ecological communities increases with species diversity, the role of vertebrate animals in the carbon cycle remains undocumented. Here, we use an extensive dataset collected in a high-diversity Amazonian system to parse out the relationship between animal and plant species richness, feeding interactions, tree biomass and carbon concentrations in soil. Mammal and tree species richness is positively related to tree biomass and carbon concentration in soil-and the relationship is mediated by organic remains produced by vertebrate feeding events. Our research advances knowledge of the links between biodiversity and carbon cycling and storage, supporting the view that whole community complexity-including vertebrate richness and trophic interactions-drives ecosystem function in tropical systems. Securing animal and plant diversity while protecting landscape integrity will contribute to soil nutrient content and carbon retention in the biosphere.

Author Correction: Mammal diversity influences the carbon cycle through trophic interactions in the Amazon.

In the version of this Article originally published, the surname of Ted K. Raab was misspelt. This error has now been corrected in all versions of the Article.

Differences in pollination success between local and foreign flower color phenotypes: a translocation experiment with Gentiana lutea (Gentianaceae).

BACKGROUND: The adaptive maintenance of flower color variation is frequently attributed to pollinators partly because they preferentially visit certain flower phenotypes. We tested whether Gentiana lutea-which shows a flower color variation (from orange to yellow) in the Cantabrian Mountains range (north of Spain)-is locally adapted to the pollinator community. METHODS: We transplanted orange-flowering individuals to a population with yellow-flowering individuals and vice versa, in order to assess whether there is a pollination advantage in the local morph by comparing its visitation rate with the foreign morph. RESULTS: Our reciprocal transplant experiment did not show clear local morph advantage in overall visitation rate: local orange flowers received more visits than foreign yellow flowers in the orange population, while both local and foreign flowers received the same visits in the yellow population; thus, there is no evidence of local adaptation in Gentiana lutea to the pollinator assemblage. However, some floral visitor groups (such as Bombus pratorum, B. soroensis ancaricus and B. lapidarius decipiens) consistently preferred the local morph to the foreign morph whereas others (such as Bombus terrestris) consistently preferred the foreign morph. DISCUSSION: We concluded that there is no evidence of local adaptation to the pollinator community in each of the two G. lutea populations studied. The consequences for local adaptation to pollinator on G. lutea flower color would depend on the variation along the Cantabrian Mountains range in morph frequency and pollinator community composition.

Flower color preferences of insects and livestock: effects on Gentiana lutea reproductive success.

Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution. Gentiana lutea shows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed in G.lutea, play a role in G. lutea flower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding on G. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affect G. lutea reproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation of G. lutea is not affected by insect herbivores or grazing livestock.

Is there a hybridization barrier between Gentiana lutea color morphs?

In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.

Selective Pressures Explain Differences in Flower Color among Gentiana lutea Populations.

Flower color variation among plant populations might reflect adaptation to local conditions such as the interacting animal community. In the northwest Iberian Peninsula, flower color of Gentiana lutea varies longitudinally among populations, ranging from orange to yellow. We explored whether flower color is locally adapted and the role of pollinators and seed predators as agents of selection by analyzing the influence of flower color on (i) pollinator visitation rate and (ii) escape from seed predation and (iii) by testing whether differences in pollinator communities correlate with flower color variation across populations. Finally, (iv) we investigated whether variation in selective pressures explains flower color variation among 12 G. lutea populations. Flower color influenced pollinator visits and differences in flower color among populations were related to variation in pollinator communities. Selective pressures on flower color vary among populations and explain part of flower color differences among populations of G. lutea. We conclude that flower color in G. lutea is locally adapted and that pollinators play a role in this adaptation.

Effects of cattle management on oak regeneration in northern Californian Mediterranean oak woodlands.

Oak woodlands of Mediterranean ecosystems, a major component of biodiversity hotspots in Europe and North America, have undergone significant land-use change in recent centuries, including an increase in grazing intensity due to the widespread presence of cattle. Simultaneously, a decrease in oak regeneration has been observed, suggesting a link between cattle grazing intensity and limited oak regeneration. In this study we examined the effect of cattle grazing on coast live oak (Quercus agrifolia Née) regeneration in San Francisco Bay Area, California. We studied seedling, sapling and adult density of coast live oak as well as vertebrate herbivory at 8 independent sites under two grazing conditions: with cattle and wildlife presence (n = 4) and only with wildlife (n = 4). The specific questions we addressed are: i) to what extent cattle management practices affect oak density, and ii) what is the effect of rangeland management on herbivory and size of young oak plants. In areas with cattle present, we found a 50% reduction in young oak density, and plant size was smaller, suggesting that survival and growth young plants in those areas are significantly limited. In addition, the presence of cattle raised the probability and intensity of herbivory (a 1.5 and 1.8-fold difference, respectively). These results strongly suggest that the presence of cattle significantly reduced the success of young Q. agrifolia through elevated herbivory. Given the potential impact of reduced recruitment on adult populations, modifying rangeland management practices to reduce cattle grazing pressure seems to be an important intervention to maintain Mediterranean oak woodlands.

Selective pressure along a latitudinal gradient affects subindividual variation in plants.

Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution.