Does the individual matter? Quantifying the role of intraspecific variation and phenotypic plasticity in plant responses to climate change

Our ability to understand the underlying morphological and physiological responses of plants to changing temperature and precipitation regimes is crucial, as we seek to construct increasingly complex models to predict how ecosystems may respond to climate change. Here, I investigate trait variation and phenotypic plasticity at the species and population level using glasshouse experiments, field transplant manipulations, and large scale, multi-habitat, multi-species observational work. Climate change models predict warming temperatures and increasingly variable precipitation and snow cover across the Australian Alps. Plasticity in water use traits and responsiveness to extremes in temperature may become important for the establishment and persistence of Australian alpine plants. Plants from relatively lower elevations inhabit a more heterogeneous environment with more frequent frosts, greater temperature extremes, and higher evapotranspiration. To test whether adaptive plasticity may be more common at lower elevations, I investigated the extent of plasticity and its adaptive value using a glasshouse and field experiment. To test the responses of reduced water availability and determine if plasticity varies across elevation, seeds of three alpine species from low and high elevation sites were grown under ample and water-limited conditions in a glasshouse. Patterns of plasticity were highly variable among species and among traits within species, however, responses were independent of elevation. Furthermore, there were few instances of adaptive plastic responses. Given the lack elevational variation in plant responses, there is need to understand the extent to which microhabitat variation within a given elevation may be important in shaping the persistence of these alpine species. Climatic changes leading to decreasing snowfall and earlier snowmelt in alpine areas may expose the underlying plants to frosts and wide range of thermal extremes. To test how populations from different elevations vary in their capacity to respond to such thermal extremes, I conducted a field manipulation using alpine seedlings in open-top chambers (OTCs). I proposed that seedlings from environments with greater thermal ranges would have a greater capacity to acclimate to warming temperatures and tolerate freezing events. The warmer conditions provided by the OTCs significantly increased seedling mortality, but seedlings that survived grew slightly taller. Warming did not affect freezing resistance, leaf production or photosynthetic efficiency. There was little evidence of intraspecific variation. A warming climate exposing plants to extreme events may lead to a reduction in seedling establishment and survival, although survivors may not exhibit any ongoing detrimental effects. The links between ecology and evolution are driven by the variation in species traits, and these inform our capacity to predict species and community responses to changing conditions. In this final section, I sought to determine: 1) the extent of variation in trait values and plasticity at habitat to site scales, and among species and individuals; 2) whether patterns of variation were consistent across plant functional traits, and; 3) whether trait variation was associated with increased fitness consistent with adaptive plastic responses. I used field data from three habitats, six sites, 36 species, and repeated sampling of 30 individuals per species, resulting in over 200,000 leaf samples. Differences between species explained the largest component of variation in trait values and trait plasticity. A large proportion of variance in plasticity was explained by among individual variation, which, as the level at which selection acts, is important. That said, there were very few instances where indices of plasticity correlated with measures of fitness, providing little evidence of adaptive plasticity across the study

Evaluation of the full set of habitat suitability models for vulnerable marine ecosystem indicator taxa in the South Pacific high seas

\ua9 2024 The Authors. Fisheries Management and Ecology published by John Wiley & Sons Ltd. In the high seas, regional fishery management organisations are required to implement measures to prevent significant adverse impacts on vulnerable marine ecosystems (VMEs). Our objectives were to develop habitat suitability models for use in the spatial management of bottom fisheries in the South Pacific and to evaluate these and existing models using independent data from high-quality seafloor imagery. Presence-only models for seven VME indictor taxa were developed to complement previous modelling. Evaluation of habitat suitability models using withheld data indicated high mean True Skill Statistic scores of 0.44–0.64. Most habitat suitability models performed adequately when assessed with independent data on taxon presence and absence but were poor surrogates for abundance. We therefore advocate caution when using presence-only models for spatial management and call for more systematically collected data to develop abundance models

Independent statistical validation of the New Zealand Seafloor Community Classification

\ua9 2024 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons Ltd. The New Zealand Seafloor Community Classification (NZSCC) is a national-scale numerical community classification which depicts compositional turnover of 1716 taxa (demersal fish, reef fish, benthic invertebrates and macroalgae) classified into 75 groups representing seafloor communities. To ensure the continual use of the NZSCC for spatial planning and reporting, a robust maintenance framework must be set in place; key to this is being able to assess the ability of the classification to represent (discriminate between) different seafloor communities. Here we describe an approach for validating the NZSCC using temporally independent evaluation data for demersal fish and benthic invertebrates (the latter sampled via a different method), which identifies whether the NZSCC represents different seafloor communities (i.e., assesses classification strength), evaluates the underlying statistical model, and considers heterogeneity in environmental coverage and statistical uncertainty. Additionally, the availability of abundance estimates for these evaluation datasets provides an opportunity to test whether the NZSCC—which was developed using presence-absence data—can reflect abundance-weighted seafloor communities. The ANOSIM global R values (measuring classification strength) were 0.53 and 0.46 (and significant at the 1% level) for demersal fish and benthic invertebrates, respectively, indicating that the NZSCC groups define biologically distinctive environments. The proportion of significant inter-group differences were very high (95% and 97% for demersal fish and benthic invertebrates, respectively) suggesting NZSCC groups were distinct from each other in their taxonomic composition. There were positive relationships between the evaluation datasets and the underlying statistical model. There was no evidence of these relationships being affected by the statistical uncertainty of the NZSCC. NZSCC model validation metrics using abundance evaluation data were also moderately high (albeit lower than for presence-absence for invertebrates) suggesting that the NZSCC, can at least in part, represent variation in abundance-weighted communities. Results presented here suggest that the existing NZSCC is currently fit-for-purpose for informing management decisions

IDEAcology: An interface to streamline and facilitate efficient, rigorous expert elicitation in ecology

Here, we demonstrate how IDEAcology aids in preparing for and implementing a structured expert elicitation using the IDEA protocol, an iterative quantitative expert elicitation framework. Expert judgement is used to inform decision-making on environmental assessment and management when imminent decisions are required, and quantitative data are absent or uninformative. Structured elicitation protocols can help improve the final judgements derived from experts, but they can also be administratively heavy and time-consuming, requiring manual collation of experts' estimates and rationales, construction and dissemination of summary plots for discussion and collating final estimates post-discussion. These challenges highlight the need for a centralised portal that enables synchronous access by all contributors, real-time structured facilitation of discussion, whether in person or online, and streamlined data management. To meet this need, we developed the IDEAcology interface (www.ideacology.com) to support data collation, summary, interactions and ultimately the deployment of structured expert elicitation using the IDEA protocol. The IDEAcology interface is designed to be a central portal for scientists and practitioners to easily implement structured expert elicitation projects, while also facilitating data management by providing a reliable and efficient way for elicitation managers to design and run an elicitation, and for experts to input, visualise and cross-examine estimates. The key advantages that IDEAcology provides include an easy-to-use interface with synchronous access to a single platform, reducing logistic difficulties, facilitating transparent discussion, improving the accuracy of estimates, enabling fast and efficient reporting by providing analysis-ready data outputs and lastly, flexibility in the types of elicitation questions that can be accommodated in the interface.publishedVersio

Communicating the value of marine conservation using an ecosystem service matrix approach

Matrix approaches are useful for linking ecosystem services to habitats that underpin their delivery. Matrix applications in marine ecosystem services research have been primarily qualitative, focusing on 'habitat presence' without including other attributes that effect service potential. We developed an evidence-based matrix approach of Ecosystem Service Potential (ESP) for New Zealand benthic marine habitats, and used two marine reserves to demonstrate that integrating information on the spatial extent and quality of habitats improved ESP evaluation. The two case studies identified substantial spatio-temporal variability in ESP: within one reserve, specific ESP showed an approximately 1.5-fold increase in the 29 years following protection. A comparison of two reserves found that the spatial extent of habitats contributing to the medicinal resources and waste-water treatment were 5 and 53 times greater respectively in one relative to the other. Integrating habitat area and quality with the ESP matrix improves on previous marine matrix-based approaches, providing a better indication of service potential. The matrix approach helps to communicate the non-market value of supporting and regulating services and can be used by resource managers to identify and track the potential for benefits derived from benthic marine habitats within existing, or new, marine protected areas

Persist in place or shift in space? Evaluating the adaptive capacity of species to climate change

Assessing the vulnerability of species to climate change serves as the basis for climate-adaptation planning and climate-smart conservation, and typically involves an evaluation of exposure, sensitivity, and adaptive capacity (AC). AC is a species’ ability to cope with or adjust to changing climatic conditions, and is the least understood and most inconsistently applied of these three factors. We propose an attribute-based framework for evaluating the AC of species, identifying two general classes of adaptive responses: “persist in place” and “shift in space”. Persist-in-place attributes enable species to survive in situ, whereas the shift-in-space response emphasizes attributes that facilitate tracking of suitable bioclimatic conditions. We provide guidance for assessing AC attributes and demonstrate the framework's application for species with disparate life histories. Results illustrate the broad utility of this generalized framework for informing adaptation planning and guiding species conservation in a rapidly changing climate.publishedVersio

Predicting species and community responses to global change using structured expert judgement : an Australian mountain ecosystems case study

Conservation managers are under increasing pressure to make decisions about the allocation of finite resources to protect biodiversity under a changing climate. However, the impacts of climate and global change drivers on species are outpacing our capacity to collect the empirical data necessary to inform these decisions. This is particularly the case in the Australian Alps which has already undergone recent changes in climate and experienced more frequent large-scale bushfires. In lieu of empirical data, we used a structured expert elicitation method (the IDEA protocol) to estimate the abundance and distribution of nine vegetation groups and 89 Australian alpine and subalpine species by the year 2050. Experts predicted that most alpine vegetation communities would decline in extent by 2050; only woodlands and heathlands are predicted to increase in extent. Predicted species-level responses for alpine plants and animals were highly variable and uncertain. In general, alpine plants spanned the range of possible responses, with some expected to increase, decrease or not change in cover. By contrast, almost all animal species are predicted to decline or not change in abundance or elevation range; more species with water-centric life-cycles are expected to decline in abundance than other species. While long-term ecological data will always be the gold-standard in informing the future of biodiversity, the method and outcomes outlined here provide a pragmatic and coherent basis upon which to start informing conservation policy and management in the face of rapid change and paucity of data