Ira Loren Wiggins

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.

Tree species in the Pinaceae are some of the most widely introduced non-native tree species globally, especially in the southern hemisphere. In New Zealand, plantations of radiata pine ( Pinus radiata D. Don) occupy c . 1.6 million ha and form 90% of planted forests. Although radiata pine has naturalized since 1904, there is a general view in New Zealand that this species has not invaded widely. We comprehensively review where radiata pine has invaded throughout New Zealand. We used a combination of observational data and climate niche modelling to reveal that invasion has occurred nationally. Climate niche modelling demonstrates that while current occurrences are patchy, up to 76% of the land area (i.e. 211,388 km 2 ) is climatically capable of supporting populations. Radiata pine has mainly invaded grasslands and shrublands, but also some forests. Notably, it has invaded lower-statured vegetation, including three classes of naturally uncommon ecosystems, primary successions and secondary successions. Overall, our findings demonstrate pervasive and ongoing invasion of radiata pine outside plantations. The relatively high growth rates and per individual effects of radiata pine may result in strong effects on naturally uncommon ecosystems and may alter successional trajectories. Local and central government currently manage radiata pine invasions while propagule pressure from existing and new plantations grows, hence greater emphasis is warranted both on managing current invasions and proactively preventing future radiata pine invasions. We therefore recommend a levy on new non-native conifer plantations to offset costs of managing invasions, and stricter regulations to protect vulnerable ecosystems. A levy on economic uses of invasive species to offset costs of managing invasions alongside stricter regulations to protect vulnerable ecosystems could be a widely adopted measure to avert future negative impacts.

Western Ecuador harbours high plant diversity and endemism. The region of Manabí has known intense deforestation over the last decades, but lowland rain forests persist in a network of small forest fragment patches. Here, we describe two new magnoliid tree species from a small privately owned forest fragment known as La Esperanza reserve, in the El Carmen canton (Manabí): Aniba ecuadorica (Lauraceae) and Guatteria esperanzae (Annonaceae). For both species a detailed morphological description, a preliminary conservation status following IUCN criteria, distribution maps and high quality photographs are provided. This represents the second species of Aniba known to occur in western Ecuador, while there are 14 species of Guatteria documented for Ecuador west of the Andes. Aniba ecuadorica is only known from two localities and has a preliminary IUCN conservation status of Critically Endangered, while Guatteria esperanzae is known from six localities and is suggested to be Endangered. Finally, we provide a quick overview of Guatteria species in western Ecuador with a key to the species in the region. The description of these two new tree species underlines the important need of prospection and conservation of the remnant forests in the Manabí region of western Ecuador. We also stress the importance of privately owned forest fragments for biodiversity conservation.

Digital point‐occurrence records from the Global Biodiversity Information Facility (GBIF) and other data providers enable a wide range of research in macroecology and biogeography. However, data errors may hamper immediate use. Manual data cleaning is time‐consuming and often unfeasible, given that the databases may contain thousands or millions of records. Automated data cleaning pipelines are therefore of high importance. Taking North American Ephedra as a model, we examined how different data cleaning pipelines (using, e.g., the GBIF web application, and four different R packages) affect downstream species distribution models (SDMs). We also assessed how data differed from expert data. From 13,889 North American Ephedra observations in GBIF, the pipelines removed 31.7% to 62.7% false positives, invalid coordinates, and duplicates, leading to datasets between 9484 (GBIF application) and 5196 records (manual‐guided filtering). The expert data consisted of 704 records, comparable to data from field studies. Although differences in the absolute numbers of records were relatively large, species richness models based on stacked SDMs (S‐SDM) from pipeline and expert data were strongly correlated (mean Pearson's r across the pipelines: .9986, vs. the expert data: .9173). Our results suggest that all R package‐based pipelines reliably identified invalid coordinates. In contrast, the GBIF‐filtered data still contained both spatial and taxonomic errors. Major drawbacks emerge from the fact that no pipeline fully discovered misidentified specimens without the assistance of taxonomic expert knowledge. We conclude that application‐filtered GBIF data will still need additional review to achieve higher spatial data quality. Achieving high‐quality taxonomic data will require extra effort, probably by thoroughly analyzing the data for misidentified taxa, supported by experts.

The most recent glacial cycles of the Pleistocene affected the distribution, population sizes, and levels of genetic structure of temperate-forest species in the main Mexican mountain systems. Our objective was to investigate the effects these cycles had on the genetic structure and distribution of a dominant species of the “mexical” vegetation across North and Central America. We studied the genetic diversity of Juniperus deppeana, a conifer distributed from the Southwestern United States to the highlands of Central America. We combined information of one plastid marker and two nuclear markers to infer phylogeographic structure, genetic diversity and demographic changes. We also characterized the climatic niche for each variety to infer the plausible area of suitability during past climatic conditions and to evaluate climatic niche discontinuities along with the species distribution. We found a marked phylogeographic structure separating the populations North and South of the Isthmus of Tehuantepec, with populations to the South of this barrier forming a distinct genetic cluster corresponding to Juniperus deppeana var. gamboana. We also found signals of population expansion in the Northern genetic cluster. Ecological niche modeling results confirmed climatic niche differences and discontinuities among J. deppeana varieties and heterogeneous responses to climatic oscillations. Overall, J. deppeana’s genetic diversity has been marked by distribution shifts, population growth and secondary contact the North, and in situ permanence in the South since the last interglacial to the present. High genetic variation suggests a wide and climatically diverse distribution during climatic oscillations. We detected the existence of two main genetic clusters, supporting previous proposals that Juniperus deppeana and Juniperus gamboana may be considered two separate species.

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.

AbstractEarly detection and eradication of invasive plants are more cost-effective than managing well-established invasive plant populations and their impacts. However, there is high uncertainty around which taxa are likely to become invasive in a given area. Horizon scanning that combines a data-driven approach with rapid risk assessment and consensus building among experts can help identify invasion threats. We performed a horizon scan of potential invasive plant threats to Florida, USA—a state with a high influx of introduced species, conditions that are generally favorable for plant establishment, and a history of negative impacts from invasive plants. We began with an initial list of 2128 non-native plant taxa that are known invaders or crop pests. We built on previous invasive species horizon scans by developing data-based criteria to prioritize 100 taxa for rapid risk assessment. The semi-automated prioritization process included selecting taxa “on the horizon” (i.e., not yet in the target location and not on a noxious weed list) with climate matching, naturalization history, “weediness” record, and global commonness. We derived overall invasion risk scores with rapid risk assessment by evaluating the likelihood of each of the taxa arriving, establishing, and having an impact in Florida. Then, following a consensus-building discussion, we identified six plant taxa as high risk, with overall risk scores ranging from 75 to 100 out of a possible 125. The six taxa are globally distributed, easily transported to new areas, found in regions with climates similar to Florida’s, and can impact native plant communities, human health, or agriculture. Finally, we evaluated our initial and final lists for potential biases. Assessors tended to assign higher risk scores to taxa that had more available information. In addition, we identified biases towards four plant families and certain geographical regions of origin. Our horizon scan approach identified taxa conforming to metrics of high invasion risk and used a methodology refined for plants that can be applied to other locations.

The consequences of rising temperatures for trees will vary between species based on their abilities to acclimate their leaf thermoregulatory traits and photosynthetic thermal tolerances. We tested the hypotheses that adult trees in warmer growing conditions (1) acclimate their thermoregulatory traits to regulate leaf temperatures and (2) acclimate their thermal tolerances such that tolerances are positively correlated with leaf temperature, and that (3) species with broader thermal niche breadths have greater acclimatory abilities. To test these hypotheses, we measured leaf traits and thermal tolerances of seven focal tree species across steep thermal gradients in Miami’s urban heat island. We found that some functional traits varied significantly across air temperatures within species. For example, leaf thickness increased with maximum air temperature in three species, and leaf mass per area and leaf reflectance both increased with air temperature in one species. Only one species was marginally more homeothermic than expected by chance due to acclimation of its thermoregulatory traits, but this acclimation was insufficient to offset elevated air temperatures. Thermal tolerances acclimated to higher maximum air temperatures in two species. As a result of limited acclimation, leaf Thermal Safety Margins (TSMs) were narrower for trees in hotter areas. We found some support for our hypothesis that species with broader thermal niches are better at acclimating in order to maintain more-stable TSMs across the temperature gradients. These findings suggest that trees have limited abilities to acclimate to high temperatures and that thermal niche specialists may be at a heightened risk of thermal stress as global temperatures continue to rise.

Identifying the environmental drivers of the global distribution of succulent plants using the Crassulacean acid metabolism pathway of photosynthesis has previously been investigated through ensemble‐modeling of species delimiting the realized niche of the natural succulent biome. An alternative approach, which may provide further insight into the fundamental niche of succulent plants in the absence of dispersal limitation, is to model the distribution of selected species that are globally widespread and have become naturalized far beyond their native habitats. This could be of interest, for example, in defining areas that may be suitable for cultivation of alternative crops resilient to future climate change. We therefore explored the performance of climate‐only species distribution models (SDMs) in predicting the drivers and distribution of two widespread CAM plants, Opuntia ficus‐indica and Euphorbia tirucalli. Using two different algorithms and five predictor sets, we created distribution models for these exemplar species and produced an updated map of global inter‐annual rainfall predictability. No single predictor set produced markedly more accurate models, with the basic bioclim‐only predictor set marginally out‐performing combinations with additional predictors. Minimum temperature of the coldest month was the single most important variable in determining spatial distribution, but additional predictors such as precipitation and inter‐annual precipitation variability were also important in explaining the differences in spatial predictions between SDMs. When compared against previous projections, an a posteriori approach correctly does not predict distributions in areas of ecophysiological tolerance yet known absence (e.g., due to biotic competition). An updated map of inter‐annual rainfall predictability has successfully identified regions known to be depauperate in succulent plants. High model performance metrics suggest that the majority of potentially suitable regions for these species are predicted by these models with a limited number of climate predictors, and there is no benefit in expanding model complexity and increasing the potential for overfitting.

Melinis repens subsp. repens is an annual herb native to Africa and southwestern Asia. In 2008, this species was detected growing in road verges and showing a reduced occupancy area of 6 km2 in a natural area of the southern Iberian Peninsula in the province of Malaga (Andalusia, Spain). The rest of the existing European records of this species comes from the Czech Republic, the Italian Peninsula, and Great Britain and can be considered casual. Furthermore, this species has become naturalised in Sardinia. The aim of this work is to study the invasion status, habitats, potential impacts, invasive behaviour, and pathways of introduction of Melinis repens subsp. repens in the southern Iberian Peninsula (Spain) to contribute to the control of this species. This species was most probably introduced into Europe for ornamental, fodder, or slope stabilization purposes. Our field work revealed this species has become naturalised in several habitats of Malaga and Granada provinces (Andalusia) occupying an area of 263 km2 in 2021. It behaves as a pioneer species that colonizes disturbed road margins and occurs in the same habitat as Cenchrus setaceus. Melinis repens subsp. repens can become dominant in natural EUNIS habitats and can also occupy cultivated areas. Because of the high occupancy area detected, and because the species has been assigned to the European Union List of Invasive Alien Plants based on the EPPO prioritization process, this plant should be considered the object of a control programme and its use should be legally prohibited in Spain, and more largely in European Mediterranean areas.