William Godsoe

Both theory and experiment indicate that biodiversity may increase productivity. However, theory tends to focus on long‐term equilibria, while experiments are most concerned with short‐term effects. An implication of this is that existing theoretical predictions may not match results of experiments. The purpose of our paper is to explore diversity–productivity mechanisms that can work on both short and long‐term trends. We start from short term theory on population growth and analyze the conditions under which positive diversity–productivity relationships emerge. Consistent with contemporary predictions, we show that species diversity can directly increase productivity by increasing the importance of niche differences. The case is not so simple for selection. Previous authors have suggested that biodiversity shapes productivity through a form of selection: species diversity facilitates the increase in abundance of successful species relative to others leading to greater overall productivity. This mechanism is thought to be analogous to natural selection in evolution, but focuses on different species rather than different genotypes. We show that this analogy is incomplete. When the formal definition of selection is applied, selection does not affect absolute productivity. Instead, selection affects the rate of change of productivity over time. As a result, measuring the effect of selection requires measurements from a minimum of three different time points so that multiple measures of productivity can be contrasted. We illustrate how to measure selection in competition experiments. These results demonstrate that diversity can influence productivity through a broader range of mechanisms than those that have been emphasized in ecology. Our results show that this disconnect between theory and experiment can be reconciled by moving past individual observations of productivity and modeling how productivity changes over time.

Climatic niche shifts have been documented for plant species introduced into new regions, however the underlying mechanisms are poorly understood. Niche shifts into novel climates are particularly difficult to predict as previous occurrence data cannot reveal whether these novel climates are within species' fundamental niche limits. We have previously shown that three globally widespread species ( Rumex obtusifolius, R. crispus, R. conglomeratus ) have undergone a realised niche shift into both analogue and non‐analogue climates in New Zealand. Here we tested two alternative explanations for this realized niche shift 1) that weeds have adapted since introduction, potentially indicating shifts in their fundamental niches, or 2) that they were preadapted to these climates prior to their arrival. For each species, we collected seeds from the native range (United Kingdom) and their introduced range (New Zealand) and established common gardens in the introduced range under climates either analogous or novel compared to the native range. We compared the relative fitness of individuals from the native and introduced ranges for each species across three critical life stages: germination, survival to reproduction, and fertility. Contrary to expectations, individuals from the native range performed similarly to or better than individuals from the introduced range under all climates. Rumex obtusifolius , performed better under non‐analogue climatic conditions compared to the analogue climate common garden. Our results show little‐to‐no evidence that these species have locally adapted to their environments since introduction, and where differences in performance between individuals from different ranges occurred, individuals from the native range typically outperformed individuals from local populations. We provide empirical evidence that even globally widespread species, as opposed to only range restricted species, undergo realised niche shifts representing previously unmeasured environmental tolerances. We highlight the pressing need for a greater understanding of species' fundamental niches to understand the potential extent of biological invasions.

Urban waterways are reservoirs and vectors of antimicrobial resistance (AMR), yet AMR is not routinely measured alongside faecal indicator bacteria. Using 2 years of data on Escherichia coli and AMR in a New Zealand urban river, we tested how AMR quantification could improve water quality risk assessment. Persistently high frequencies of AMR and pathogenic E. coli sequence types were detected near homes and places of recreation. We measured AMR phenotypes and gene mobilisation by conjugation. We compared phenotyping with genotyping by whole‐genome sequencing to assess whether phenotyping could serve as a proxy for costly sequencing methods. Results suggest that one AMR phenotype could act as a sentinel for less common but problematic resistances, potentially due to plasmid‐based linkage of antibiotic resistance genes or enrichment of clinically relevant sequence types. The study offers a low‐cost water quality monitoring strategy to meet community needs. Widespread adoption of AMR hazard reporting could support the World Health Organization's Sustainable Development Goals and Global Action Plan on AMR.

The use of animal symbolism or names is a common practice in advertising and branding. Businesses use animals to project attributes of their brand and thus contribute to public familiarity with the species. In New Zealand, birds are arguably the most prominent animals in national conservation priorities and citizen science activities. This fact reflects New Zealand's unique biogeography and the historic lack of terrestrial mammals. Here we explore the frequency with which bird names have been used in business branding over the last 70 years and examine the trend in the relative use of native, non‐native or generic names. We quantified the use of bird names in New Zealand businesses using the New Zealand Business Register, which provides details of ca. 1.6 million businesses. We identified the most frequent generic and specific names used between 1950 and 2022. We further explored associations between specific bird groups and business sectors. The prevalence of bird names in New Zealand business branding was generally low, with an increase from approximately 0.3% in the 1950s, trebling to about 1% of all registered businesses in recent years. The representation of native species within businesses that use bird names has increased from approximately 25% in the 1950s to more than 50% today. Aside from the kiwi, the most common bird names used by businesses were generic, for example, eagle, swan, or falcon. However, of those names that could be related to a known species, 83% referred to a species native to New Zealand. We detected non‐random associations between bird groups and specific business sectors. For example, raptors were overrepresented in business names from the construction, public administration and safety sectors. We provide an empirical case study on the commercially oriented usage of animal names for business branding. The increased use of bird names over time and associations between specific bird groups and business sectors may indicate socio‐cultural attributes linked to particular bird characteristics. The identification of trends and patterns could be the basis for further investigation into relationships between a species' familiarity and public perceptions, with consequent relevance to species conservation. Read the free Plain Language Summary for this article on the Journal blog.

The role of rapid adaptation during species invasions has historically been minimized with the assumption that introductions consist of few colonists and limited genetic diversity. While overwhelming evidence suggests that rapid adaptation is more prevalent than originally assumed, the demographic and adaptive processes underlying successful invasions remain unresolved. Here we leverage a large whole-genome sequence dataset to investigate the relative roles of colonization history and adaptation during the worldwide invasion of the forage crop, Trifolium repens (Fabaceae). We show that introduced populations encompass high levels of genetic variation with little evidence of bottlenecks. Independent colonization histories on different continents are evident from genome-wide population structure. Five haploblocks—large haplotypes with limited recombination—on three chromosomes exist as standing genetic variation within the native and introduced ranges and exhibit strong signatures of parallel climate-associated adaptation across continents. Field experiments in the native and introduced ranges demonstrate that three of the haploblocks strongly affect fitness and exhibit patterns of selection consistent with local adaptation across each range. Our results provide strong evidence that large-effect structural variants contribute substantially to rapid and parallel adaptation of an introduced species throughout the world.

Changes in biodiversity reflect processes acting at multiple spatial scales, from local to global, among habitats and within communities. This complexity makes it difficult to measure mechanisms that have traditionally interested ecologists, such as environmental filters. To resolve this, we propose an approach to partition temporal changes in biodiversity into contributions from selection at multiple scales. We applied this approach to study changes in the biodiversity of invertebrate herbivores from a large‐scale, plant community experiment. Though the experiment was designed to foster distinct insect communities due to differences in host plants, our approach showed that selection among these treatments was a negligible facet of diversity change. These effects were swamped by rapid changes in relative abundances of aphids due to both immigration and selection across the metacommunity. More broadly, our work highlights how total change in biodiversity across a biogeographic region can be partitioned into logically distinct mechanisms.

A fundamental problem in ecology is understanding the changes in species composition among sites (i.e. beta‐diversity). It is unclear how spatial heterogeneity in species occupancy across sites shapes patterns of beta‐diversity. To address this question, we develop probabilistic models that consider two spatial or temporal sites, where presence probabilities vary both among species and between the sites. We derive analytical and approximate formulae for the expectation of pairwise beta‐diversity. Using a graphical tool, stochastic incidence plots (SIPs), which depict the presence probabilities in two sites along species labels, we develop a means to conceptualize the heterogeneity in presence probabilities: the steepness or unevenness of SIPs reflects species‐level heterogeneity, while the degree of overlap between SIPs indicates site‐level heterogeneity. We find that when SIPs completely overlap (i.e. two sites have the same presence probability for each species), flat SIPs ‐ with all species having the same presence probability ‐ maximize the expected beta‐diversity. We refer to this prediction as the ‘transfer principle for beta'. Second, using SIPs and the probabilistic method in a two‐species scenario, we demonstrate that beta‐diversity is lower when SIPs are parallel compared to when they are anti‐parallel. We also find that this prediction is consistent with the well‐known checkerboard pattern in incidence matrices. Finally, we apply the method to the species distribution models for five woodpecker species in Switzerland, showing that their spatial distributions will change significantly. Overall, this work improves our understanding of how pairwise beta‐diversity responds to occupancy heterogeneity.

Changes in biodiversity reflect processes acting at multiple spatial scales, including globally, among habitats and within communities. This complexity makes it difficult to analyse the mechanisms that change biodiversity over time. To resolve this, we propose a novel approach to partition temporal changes in biodiversity into contributions from selection at multiple scales. We apply this approach to study changes in the biodiversity of invertebrate herbivores from a large-scale, plant community experiment. Though the experiment was designed to foster distinct insect communities due to differences in host plants, our approach shows that selection among these treatments was a negligible facet of diversity change. Instead, the dominant source of community dynamics was rapid changes in the relative abundances of individual species. These shifts produced surprisingly small changes in biodiversity. More broadly our work highlights how total change in biodiversity across a biogeographic region can be partitioned into logically distinct mechanisms.

Experiments suggest that increasing species’ diversity increases productivity over short observation periods. At equilibrium, theory predicts that diversity may increases productivity, such as in communities of coexisting competitors. This suggests a disconnect with theory focusing on long term trends and experiments observing short-term population growth. To resolve this gap, we start from short term models of population growth and analyze the conditions under which diversity productivity relationships emerge. Using this approach, we show that selection (as it is formally defined in dynamic models) does not affect productivity. Instead, selection changes productivity over time. In contrast, niche complementarity can change productivity directly. We illustrate how to measure each of the terms in competition experiments. These results highlight how the effects of diversity on productivity can be obscured by our choice of response variable.