John Macoun

Abstract Asplenium scolopendrium is distributed in northern temperate forests with many global biogeographic disjunctions. The species complex of A. scolopendrium has been generated by spatial segregation coupled with divergent evolution. We elucidated the biogeographic history of the A. scolopendrium complex by exploring its origin, dispersal and evolution, thus providing insights into the evolutionary history of the Tertiary floras with northern pan-temperate disjunct distributions. The results revealed that all infraspecific taxa descended from a widely distributed common ancestor in the Northern Hemisphere. This pan-temperate ancestral population formed by unidirectional westward dispersal from European origins primarily during the Early Eocene when the Earth’s climate was much warmer than today. The splitting of European, American and East Asian lineages occurred during the Early Miocene due to geo-climatic vicariances. Polyploidy events in the American ancestral populations created additional reproductive barriers. The star-shaped haplotypes in each continent indicated that local disjunctions also led to derived genotypes with potential to diverge into different taxa. This intracontinental lineage splitting is likely related to latitudinal range shift and habitat fragmentation caused by glacial cycles and climate change during the Pleistocene. The evolutionary history of the A. scolopendrium complex supported the Boreotropical hypothesis exhibiting range expansion during the Early Eocene Climatic Optimum.

Abstract. Artemisia, along with Chenopodiaceae, is the dominant component growing in the desert and dry grassland of the Northern Hemisphere. Artemisia pollen with its high productivity, wide distribution, and easy identification is usually regarded as an eco-indicator for assessing aridity and distinguishing grassland from desert vegetation in terms of the pollen relative abundance ratio of Chenopodiaceae/Artemisia (C/A). Nevertheless, divergent opinions on the degree of aridity evaluated by Artemisia pollen have been circulating in the palynological community for a long time. To solve the confusion, we first selected 36 species from nine clades and three outgroups of Artemisia based on the phylogenetic framework, which attempts to cover the maximum range of pollen morphological variation. Then, sampling, experiments, photography, and measurements were taken using standard methods. Here, we present pollen datasets containing 4018 original pollen photographs, 9360 pollen morphological trait measurements, information on 30 858 source plant occurrences, and corresponding environmental factors. Hierarchical cluster analysis on pollen morphological traits was carried out to subdivide Artemisia pollen into three types. When plotting the three pollen types of Artemisia onto the global terrestrial biomes, different pollen types of Artemisia were found to have different habitat ranges. These findings change the traditional concept of Artemisia being restricted to arid and semi-arid environments. The data framework that we designed is open and expandable for new pollen data of Artemisia worldwide. In the future, linking pollen morphology with habitat via these pollen datasets will create additional knowledge that will increase the resolution of the ecological environment in the geological past. The Artemisia pollen datasets are freely available at Zenodo (https://doi.org/10.5281/zenodo.6900308; Lu et al., 2022).

Accelerating climate change is expected to cause range shifts of numerous taxa worldwide. While climatic projections and predicted consequences typically focus on the future (2050 or later), a measurable change in climatic conditions has occurred over recent decades. We investigate whether recent climate change has caused measurable shifts in suitable habitat for six North American species in the highly threatened genus Cypripedium (Orchidaceae). We constructed species distribution models using a maximum entropy approach from species occurrence records, 19 bioclimatic variables, land cover data, and soil data for two decadal time intervals (1980–1989 and 2010–2019). Models were compared between time intervals to assess shifts in locality, size, fragmentation, and mean elevation of suitable habitat. For all six congeners, the centroids of suitable habitat shifted between time intervals, although the directionality varied. There was, however, consistency among species within geographic regions. Consistent with our expectations, the optimal habitat for most species shifted to a higher elevation and for western species it shifted northwards. However, the habitat for one northwestern species shifted southwards and the habitat for eastern species converged on the Great Lakes region from different directions. This work illustrates the somewhat idiosyncratic responses of congeneric species to changing climatic conditions and how the geographic region occupied by a species may be more important for predicting shifts in habitat than is the response of a closely related taxon.

We analyzed the geographical distribution of Habromys species based on distributional data from museum specimens, web databases, and literature. We recorded species-presence data of each species in 0.5° × 0.5° grid cells and biogeographic provinces in Mexico and Central America. We analyzed the association between vegetation types and land use. We carried out species distribution models of most species of Habromys and those tree species frequently harboring these mice, finding a high distributional congruence among mice and trees. Species of Habromys occur throughout the montane systems of Mexico and northern Central America, so they can be considered characteristic elements of the Neotropical montane cloud forests. All species of the genus occur in Mexico, whereas Guatemala and El Salvador have only one species. Although all species of Habromys are highly restricted and considered rare species, only one (H. simulatus) is currently protected by Mexican laws. We assigned two species to a high and four to the critical conservation risk. Habromys species contribute to the recognition of Mesoamerica as a biodiversity hotspot.

Mapping biodiversity patterns across taxa and environments is crucial to address the evolutionary and ecological dimensions of species distribution, suggesting areas of particular importance for conservation purposes. Within Cactaceae, spatial diversity patterns are poorly explored, as are the abiotic factors that may predict these patterns. We gathered geographic and genetic data from 921 cactus species by exploring both the occurrence and genetic databases, which are tightly associated with drylands, to evaluate diversity patterns, such as phylogenetic diversity and endemism, paleo-, neo-, and superendemism, and the environmental predictor variables of such patterns in a global analysis. Hotspot areas of cacti diversity are scattered along the Neotropical and Nearctic regions, mainly in the desertic portion of Mesoamerica, Caribbean Island, and the dry diagonal of South America. The geomorphological features of these regions may create a complexity of areas that work as locally buffered zones over time, which triggers local events of diversification and speciation. Desert and dryland/dry forest areas comprise paleo- and superendemism and may act as both museums and cradles of species, displaying great importance for conservation. Past climates, topography, soil features, and solar irradiance seem to be the main predictors of distinct endemism types. The hotspot areas that encompass a major part of the endemism cells are outside or poorly covered by formal protection units. The current legally protected areas are not able to conserve the evolutionary diversity of cacti. Given the rapid anthropogenic disturbance, efforts must be reinforced to monitor biodiversity and the environment and to define/plan current and new protected areas.

Societal impact statement Plant biodiversity is fundamental to the future of food security and agriculture. Berries are the most economically important fruit crops in Canada. Within this article, we explore the nutritional, cultural, and botanical importance of berries, including crop wild relatives (plant species that are closely related to domesticated crops) and plants that are significant to Indigenous Peoples. Using berries as a case study, we explore opportunities for the conservation, use, and public engagement of crop wild relatives. Our objective is to lay the groundwork for future collaborative efforts across these diverse plants. Summary Conservation of plant biodiversity, in particular crop wild relatives including those tended and cultivated by Indigenous Peoples, is critical to food security and agriculture. Building on the 2019 road map for crop wild relatives, we examine berries as a case study for crop wild relative conservation, use, and public engagement. We focus on berries due not only to their economic, cultural, and nutritional importance but also because they are consumed fresh, providing a unique opportunity for individuals and communities to connect with plants. We outline health benefits, geographic distribution, and species at risk for Canadian berries. We describe practices, strategies, and approaches used by Indigenous Peoples to steward berries and emphasize the importance of traditional knowledge. We highlight opportunities for in situ and ex situ berry conservation and use of berries in plant breeding and Indigenous foodways. Our aim is to lay the groundwork for future collaborative efforts in these areas and to showcase berries as a useful case study for conservation of food plant biodiversity and public engagement.

The spread and outbreaks of phytophagous pests are often associated with global warming. In addition to economic interest, these species may be of interest in terms of biological indication of climate changes. In this context, we considered the locust digitate leafminer Parectopa robiniella Clemens, 1863 (Lepidoptera: Gracillariidae). This phytophage was first discovered in Europe in 1970 near Milano in Italy. Since then, it has been spreading across the continent. In Ukraine, it was recorded for the first time in 2003. In 2020–2021, we found areas of massive leaf damage caused by the black locust (Robinia pseudoacacia) in locations on Trukhaniv Island in Kyiv and some places in the Kyiv administrative region. Using 1041 georeferenced records of P. robiniella across Europe and a Bayesian additive regression trees algorithm (BART), we modeled the distribution of the moth. Predictors of current climate (WorldClim v.2, CliMond v.1.2 and ENVIREM) and a black locust habitat suitability raster were employed. Sets of SDMs built for P. robiniella with and without the habitat suitability raster for the host tree performed equally well. Amongst the factors that determine the niche of the locust digitate leafminer, most important are temperature-related conditions assumed to facilitate the spread and naturalization of the pest. In Ukraine, the appearance of the moth has coincided with increasing mean annual temperatures. Particularly favorable for the species are areas in the west and south-west of the country, and Transcarpathia. In the near future, the moth could reach locations in Nordic countries, Estonia, the British Isles, Black Sea coastal areas in Turkey, further into Russia, etc.

Climate change is now a reality and is altering ecosystems, with Canada experiencing 2–4 times the global average rate of warming. This will have a critical impact on berry cultivation and horticulture. Enhancing our understanding of how wild and cultivated berries will perform under changing climates will be essential to mitigating impacts on ecosystems, culture and food security. Our objective was to predict the impact of climate change on habitat suitability of four berry producing Vaccinium species: two species with primarily northern distributions (V. uliginosum, V. vitis-idaea), one species with a primarily southern distribution (V. oxycoccos), and the commercially cultivated V. macrocarpon. We used the maximum entropy (Maxent) model and the CMIP6 shared socioeconomic pathways (SSPs) 126 and 585 projected to 2041–2060 and 2061–2080. Wild species showed a uniform northward progression and expansion of suitable habitat. Our modeling predicts that suitable growing regions for commercial cranberries are also likely to shift with some farms becoming unsuitable for the current varieties and other regions becoming more suitable for cranberry farms. Both V. macrocarpon and V. oxycoccos showed a high dependence on precipitation-associated variables. Vaccinium vitis-idaea and V. uliginosum had a greater number of variables with smaller contributions which may improve their resilience to individual climactic events. Future competition between commercial cranberry farms and wild berries in protected areas could lead to conflicts between agriculture and conservation priorities. New varieties of commercial berries are required to maintain current commercial berry farms.

In the face of global pressures of change and biodiversity loss, crop wild relatives (CWR) and wild‐utilized plants (WUS) urgently require conservation attention. To advance conservation, we assembled a national inventory of CWR and WUS in Canada. To assess current ex situ conservation, we gathered a virtual metacollection of CWR and WUS accession data from national genebanks and from botanical gardens. The inventory includes 779 CWR and WUS taxa (658 distinct species), with 263 (222 distinct species) that are related to food crops of global and national importance such as blueberry and cranberry, apple, stone fruits, strawberry, sunflower and saskatoon. Sixty‐one food crop CWR taxa are prioritized for breeding potential, and sixteen due to conservation threats. Although most food crop CWR are represented in ex situ collections (91% of species), representation of within‐species diversity is low (median = 5% of Canadian ecogeographic types represented per species). Poor representation of within‐species diversity demands an integrative conservation strategy that emphasizes in situ protection especially focusing on wild‐populations in Canada's southern ecoregions where diversity is concentrated. While genebank collections represent more species and higher accession counts per species, botanical gardens include living collections of charismatic fruit crop relatives and other woody‐perennials that are well situated to advance conservation by raising broader awareness of CWR and WUS. To promote further conservation, we present a web application that enables conservation planners and practitioners to identify local CWR and WUS diversity and to identify within‐species ecogeographic types that are underrepresented in ex situ conservation systems.

According to the ‘fitness‐suitability' hypothesis, ongoing changes in climate are expected to affect habitat suitability and hence species' fitness. In trees, differences in fitness may manifest as changes in growth rates, which will alter carbon uptake. Using tree‐ring data, we calculated > 1.5 million annual stem growth rate estimates (standardized for tree size) for 15 677 trees representing 37 species from 558 populations throughout eastern North America. We used collections data and species distribution models to estimate each population's climatic suitability from 1900 to 2010. We then assessed the relationships between growth, suitability and time using linear mixed‐effects models. We found that stem growth rates decreased significantly through time independent of changes in climate suitability and that relationships between growth rates and climate suitability were highly variable across species. Contrary to expectations, we found that growth rates were negatively correlated with species' climate suitability, a relationship that was consistent over time for gymnosperms and became more negative through time for angiosperms. These results may suggest that stem growth rates are not a good proxy for fitness and/or that unidentified factors may be slowing tree growth and outweighing any potential benefits of climate change and increasing atmospheric CO2 concentrations. Regardless of the cause, this finding indicates that we should not count on the increased growth of eastern North American trees to help offset anthropogenic carbon emissions.