Shoreline armor removal to restore variability in intertidal ecosystems

Humans have modified marine nearshore ecosystems through the construction of shoreline armoring. Armoring, in the form of seawalls and bulkheads, reduces the mean abundance and quantity of key biological features of shoreline ecosystems, such as the coverage, depth, and composition of beach wrack, the number of beached logs, and the density and richness of supratidal invertebrates. Armoring also affects the physical and biological composition and diversity of shoreline ecosystems and communities – altering the makeup of sediments, beach wrack, and invertebrates, for example. Less is known, however, about changes in the amount of variability – both over time and space – of these important ecological responses. Natural variation in physical and biological variables can itself be an indicator of ecosystem health and effectiveness of restoration. Working alongside citizen scientists, we found that beach wrack, beach logs, and supratidal invertebrates were not only more abundant and diverse at natural (never armored) strata compared to armored strata, but also had higher variation. In many, but not all cases, restoration recovered this variation. Importantly, we found that differences among sample sites, rather than across sample years, explained more of the variation in ecological responses. Because shoreline armoring is an inherently human activity, public perception of this variability is key to the social context of restoration success. Participation in data collection through citizen science endeavors is one way to encourage an appreciation for natural variability within and across landscapes. We implore that shoreline monitoring efforts should evaluate and communicate ecosystem variability as a key indicator of restoration success

Socio-eco-evolutionary dynamics in cities

Cities are uniquely complex systems regulated by interactions and feedbacks between nature and human society. Characteristics of human society-including culture, economics, technology and politics-underlie social patterns and activity, creating a heterogeneous environment that can influence and be influenced by both ecological and evolutionary processes. Increasing research on urban ecology and evolutionary biology has coincided with growing interest in eco-evolutionary dynamics, which encompasses the interactions and reciprocal feedbacks between evolution and ecology. Research on both urban evolutionary biology and eco-evolutionary dynamics frequently focuses on contemporary evolution of species that have potentially substantial ecological-and even social-significance. Still, little work fully integrates urban evolutionary biology and eco-evolutionary dynamics, and rarely do researchers in either of these fields fully consider the role of human social patterns and processes. Because cities are fundamentally regulated by human activities, are inherently interconnected and are frequently undergoing social and economic transformation, they represent an opportunity for ecologists and evolutionary biologists to study urban "socio-eco-evolutionary dynamics." Through this new framework, we encourage researchers of urban ecology and evolution to fully integrate human social drivers and feedbacks to increase understanding and conservation of ecosystems, their functions and their contributions to people within and outside cities

RAPID ADAPTATION IN A NOVEL ECOSYSTEM: EVOLUTIONARY ECOLOGY OF WHITE SANDS LIZARDS

The species of lizards that inhabit White Sands, New Mexico provide an ideal system in which to study evolutionary and ecological interactions. Characterized by 250 square miles of gypsum sand dunes, White Sands formed in the last two to seven thousand years. Three lizard species, the Lesser Earless Lizard (Holbrookia maculata), the Southwestern Fence Lizard (Sceloporus cowlesi), and the Little Striped Whiptail (Aspidoscelis inornata) colonized White Sands since its formation and today exhibit blanched colouration, unlike their closely related dark-coloured counterparts inhabiting the surrounding Chihuahuan Desert. As both a geologically young and novel ecosystem, White Sands provides a setting for studying ecological and evolutionary changes in its colonist species. In my dissertation, I examined the ecological implications of morphological differences between White Sands and dark soils lizards and investigated the current dynamics of ecological population dynamics and natural selection on White Sands lizard populations. In Chapter I, I introduced the geological history of White Sands and the biological history of its lizard inhabitants. In Chapter II, I examined whether White Sand lizards show evidence of ecological release. Specifically, I found that there are fewer potential competitor and predator species in White Sands and the three resident species exhibit density compensation. Furthermore, one of the White Sands species, S. cowlesi, demonstrates expansion of resource use by using a greater variety of perch types than in dark soils habitats. In chapters III and IV, I explored whether ecologically relevant morphology, performance, and resource use showed evidence of ecological release and directional selection. In particular, I found that two species White Sands lizards have longer legs than their dark soils counterparts, but this does not influence their sprint speed as much as their behavioural response to a simulated predator. In addition, all three species consume a greater number of prey species in White Sands than in dark soils; however, only A. inornata eats significantly harder prey, and only H. maculata has expanded the variability of its diet in White Sands. Finally, in Chapter V, I investigated the changes in population demographics and selection on ecologically important traits in two species, S. cowlesi and H. maculata on the White Sands ecotone over two to three years. I found extreme differences in the ratio of juveniles to adults, growth, dispersal distances, and potential selection on traits between the two species over time.Thesis (Ph.D., Biology)--University of Idaho, May 201

Conserving intraspecific variation for nature’s contributions to people

International audienceThe rapid loss of intraspecific variation is a hidden biodiversity crisis. Intraspecific variation, which includes the genomic and phenotypic diversity found within and among populations, is threatened by local extinctions, abundance declines, and anthropogenic selection. However, biodiversity assessments often fail to highlight this loss of diversity within species. We review the literature on how intraspecific variation supports critical ecological functions and nature’s contributions to people (NCP). Results show that the main categories of NCP (material, non-material, and regulating) are supported by intraspecific variation. We highlight new strategies that are needed to further explore these connections and to make explicit the value of intraspecific variation for NCP. These strategies will require collaboration with local and Indigenous groups who possess critical knowledge on the relationships between intraspecific variation and ecosystem function. New genomic methods provide a promising set of tools to uncover hidden variation. Urgent action is needed to document, conserve, and restore the intraspecific variation that supports nature and people. Thus, we propose that the maintenance and restoration of intraspecific variation should be raised to a major global conservation objective

Data from: Survival by genotype: patterns at Mc1r are not black and white at the White Sands ecotone

Measuring links among genotype, phenotype and survival in the wild has long been a focus of studies of adaptation. We conducted a 4-year capture–recapture study to measure survival by genotype and phenotype in the Southwestern Fence Lizard (Sceloporus cowlesi) at the White Sands ecotone (transition area between white sands and dark soil habitats). We report several unanticipated findings. First, in contrast with previous work showing that cryptic blanched coloration in S. cowlesi from the heart of the dunes is associated with mutations in the melanocortin-1 receptor gene (Mc1r), ecotonal S. cowlesi showed minimal association between colour phenotype and Mc1r genotype. Second, the frequency of the derived Mc1r allele in ecotonal S. cowlesi appeared to decrease over time. Third, our capture–recapture data revealed a lower survival rate for S. cowlesi individuals with the derived Mc1r allele. Thus, our results suggest that selection at the ecotone may have favoured the wild-type allele in recent years. Even in a system where a genotype–phenotype association appeared to be black and white, our study suggests that additional factors – including phenotypic plasticity, epistasis, pleiotropy and gene flow – may play important roles at the White Sands ecotone. Our study highlights the importance of linking molecular, genomic and organismal approaches for understanding adaptation in the wild. Furthermore, our findings indicate that dynamics of natural selection can be particularly complex in transitional habitats like ecotones and emphasize the need for future research that examines the patterns of ongoing selection in other ecological ‘grey’ zones

Conclusion—Biodiversity for the People

Abstract: Imagining our global future is an extraordinary challenge. Due to our escalating climate crisis, it is uncertain how recognizable our environmental landscape will be 100–150 years from the present. Inarguably, the increased frequencies of once-in-a-lifetime storms, heat waves, droughts, and wildfires already suggest that our current context is ominous. Building solutions that minimize impending catastrophe is therefore a particularly urgent endeavor, one that will undoubtedly require transdisciplinary, agile, and resilient tools that leverage collective forms of knowledge. The development of those tools will require all peoples’ experience and knowledge, emphasizing the need for environmental equity and access. Simultaneously, conserving species will be imperative components that maintain our ecosystem health and function. This work outlines how merging environmental equity and biodiversity conservation will be an essential formula for weathering the figurative and literal storms induced by climate change. In addition, it pinpoints key priorities and gaps in urban conservation research that may be critical components to ecological application and policy designed to fight future disasters. Further, it speculates on the contexts of future urban biodiversity management landscapes if eco-equitable conservation policies are centered at multiple scales of governance. In closing, it stresses that the future blueprint for eco-equitable conservation and climate mitigation has always been embedded in the environmental justice narratives of the past

Ecological and Evolutionary Effects of Stickleback on Community Structure

<div><p>Species’ ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (<i>Gasterosteus aculeatus</i>). We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density) and evolutionary (phenotypic diversity and specialization) factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-<i>a</i> concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-<i>a</i> concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.</p> </div

The Ecological Importance Of Intraspecific Variation

Human activity is causing wild populations to experience rapid trait change and local extirpation. The resulting effects on intraspecific variation could have substantial consequences for ecological processes and ecosystem services. Although researchers have long acknowledged that variation among species influences the surrounding environment, only recently has evidence accumulated for the ecological importance of variation within species. We conducted a meta-analysis comparing the ecological effects of variation within a species (intraspecific effects) with the effects of replacement or removal of that species (species effects). We evaluated direct and indirect ecological responses, including changes in abundance (or biomass), rates of ecological processes and changes in community composition. Our results show that intraspecific effects are often comparable to, and sometimes stronger than, species effects. Species effects tend to be larger for direct ecological responses (for example, through consumption), whereas intraspecific effects and species effects tend to be similar for indirect responses (for example, through trophic cascades). Intraspecific effects are especially strong when indirect interactions alter community composition. Our results summarize data from the first generation of studies examining the relative ecological effects of intraspecific variation. Our conclusions can help inform the design of future experiments and the formulation of strategies to quantify and conserve biodiversity

Test statistics and effect sizes for planned contrasts showing the importance of stickleback ecology and evolution on different community parameters.

<p>Larger effect sizes correspond to responses of larger magnitude.</p>*<p>P<0.1,</p>†<p>P<0.05,</p>††<p>P<0.01.</p