Science Enabled by Specimen Data

Bürger, M., and J. Chory. 2024. A potential role of heat‐moisture couplings in the range expansion of Striga asiatica. Ecology and Evolution 14.

Parasitic weeds in the genera Orobanche, Phelipanche (broomrapes) and Striga (witchweeds) have a devastating impact on food security across much of Africa, Asia and the Mediterranean Basin. Yet, how climatic factors might affect the range expansion of these weeds in the context of global environmental change remains unexplored. We examined satellite‐based environmental variables such as surface temperature, root zone soil moisture, and elevation, in relation to parasitic weed distribution and environmental conditions over time, in combination with observational data from the Global Biodiversity Information Facility (GBIF). Our analysis reveals contrasting environmental and altitude preferences in the genera Striga and Orobanche. Asiatic witchweed (Striga asiatica), which infests corn, rice, sorghum, and sugar cane crops, appears to be expanding its range in high elevation habitats. It also shows a significant association with heat‐moisture coupling events, the frequency of which is rising in such environments. These results point to geographical shifts in distribution and abundance in parasitic weeds due to climate change.

Zhao, Y., G. A. O’Neill, N. C. Coops, and T. Wang. 2024. Predicting the site productivity of forest tree species using climate niche models. Forest Ecology and Management 562: 121936.

Species occurrence-based climate niche models (CNMs) serve as valuable tools for predicting the future ranges of species’ suitable habitats, aiding the development of climate change adaptation strategies. However, these models do not address an essential aspect - productivity, which holds economic significance for timber production and ecological importance for carbon sequestration and ecosystem services. In this study, we investigated the potential to extend the CNMs to predict species productivity under various climate conditions. Lodgepole pine (Pinus contorta Dougl. ex Loud.) and Douglas-fir (Pseudotsuga menziesii Franco.) were selected as our model species due to their comprehensive range-wide occurrence data and measurement of site productivity. To achieve this, we compared and optimized the performance of four individual modeling algorithms (Random Forest (RF), Maxent, Generalized Boosted Models (GBM), and Generalized Additive Model (GAM)) in reflecting site productivity by evaluating the effect of spatial filtering, and the ratio of presence to absence (p/a ratio) observations. Additionally, we applied a binning process to capture the overarching trend of climatic effects while minimizing the impact of other factors. We observed consistency in optimal performance across both species when using the unfiltered data and a 1:1.5 p/a ratio, which could potentially be extended to other species. Among the modeling algorithms explored, we selected the ensemble model combining RF and Maxent as the final model to predict the range-wide site productivity for both species. The predicted range-wide site productivity was validated with an independent dataset for each species and yielded promising results (R2 above 0.7), affirming our model’s credibility. Our model introduced an innovative approach for predicting species productivity with high accuracy using only species occurrence data, and significantly advanced the application of CNMs. It provided crucial tools and insights for evaluating climate change's impact on productivity and holds a better potential for informed forest management and conservation decisions.

Serra‐Diaz, J. M., J. Borderieux, B. Maitner, C. C. F. Boonman, D. Park, W. Guo, A. Callebaut, et al. 2024. occTest: An integrated approach for quality control of species occurrence data. Global Ecology and Biogeography.

Aim Species occurrence data are valuable information that enables one to estimate geographical distributions, characterize niches and their evolution, and guide spatial conservation planning. Rapid increases in species occurrence data stem from increasing digitization and aggregation efforts, and citizen science initiatives. However, persistent quality issues in occurrence data can impact the accuracy of scientific findings, underscoring the importance of filtering erroneous occurrence records in biodiversity analyses.InnovationWe introduce an R package, occTest, that synthesizes a growing open‐source ecosystem of biodiversity cleaning workflows to prepare occurrence data for different modelling applications. It offers a structured set of algorithms to identify potential problems with species occurrence records by employing a hierarchical organization of multiple tests. The workflow has a hierarchical structure organized in testPhases (i.e. cleaning vs. testing) that encompass different testBlocks grouping different testTypes (e.g. environmental outlier detection), which may use different testMethods (e.g. Rosner test, jacknife,etc.). Four different testBlocks characterize potential problems in geographic, environmental, human influence and temporal dimensions. Filtering and plotting functions are incorporated to facilitate the interpretation of tests. We provide examples with different data sources, with default and user‐defined parameters. Compared to other available tools and workflows, occTest offers a comprehensive suite of integrated tests, and allows multiple methods associated with each test to explore consensus among data cleaning methods. It uniquely incorporates both coordinate accuracy analysis and environmental analysis of occurrence records. Furthermore, it provides a hierarchical structure to incorporate future tests yet to be developed.Main conclusionsoccTest will help users understand the quality and quantity of data available before the start of data analysis, while also enabling users to filter data using either predefined rules or custom‐built rules. As a result, occTest can better assess each record's appropriateness for its intended application.

Ashraf, U., T. L. Morelli, A. B. Smith, and R. R. Hernandez. 2024. Aligning renewable energy expansion with climate-driven range shifts. Nature Climate Change 14: 242–246.

Fossil fuel dependence can be reduced, in part, by renewable energy expansion. Increasingly, renewable energy siting seeks to avoid significant impacts on biodiversity but rarely considers how species ranges will shift under climate change. Here we undertake a systematic literature review on the topic and overlay future renewable energy siting maps with the ranges of two threatened species under future climate scenarios to highlight this potential conflict. The authors conduct a systematic literature review on renewable energy expansion and biodiversity. Comparing renewable energy siting maps with the ranges of two threatened species under future climates, they highlight the potential conflict and need for consideration of climate-change-driven range shifts.

Souto, C. P., L. P. Zalazar, M. Tadey, and A. C. Premoli. 2024. Modeling past, present and future: Species-specific responses to climate changes in three shrub congeners from south American drylands. Journal of Arid Environments 221: 105139.

Drylands cover ca. 40% of the land global surface and deliver significant ecosystem services. These regions are the most sensitive, prone to suffer the effects of climate and distribution changes, so estimates on projected range shifts are crucial to complement traditional approaches to biodiversity conservation and sustainability. Shrubs of the Monte Desert dominate the largest temperate dryland in South America. Our goal is to assess the spatial distribution and niche overlap of three native shrubs (Larrea cuneifolia (LC), L. divaricata (LD), and L. nitida (LN)), under present climate conditions, to retrodict their potential past distribution, and anticipate their predicted range under future climate scenarios. We used ecological niche modeling that were projected to the past (LGM and Mid Holocene) and future (2050 and 2070) under two scenarios of greenhouse gas emissions and two model of global circulation. All species have high niche overlap (67–89%), but showed species-specific responses, highlighting the need to develop mitigation measures particularly for LD and LN in the face of climate change and land use pressures. Global South deserts are being highly degraded and information on future potential ranges of endemic species can support the development of sustainable conservation and management plans.

Xiao, S., S. Li, J. Huang, X. Wang, M. Wu, R. Karim, W. Deng, and T. Su. 2024. Influence of climate factors on the global dynamic distribution of Tsuga (Pinaceae). Ecological Indicators 158: 111533.

Throughout the Quaternary period, climate change has significantly influenced plant distribution, particularly affecting species within the genus Tsuga (Endl.) Carrière. This climatic impact ultimately led to the extinction of all Tsuga species in Europe. Today, there are ten recognized species of Tsuga worldwide, one of listed as a vulnerable species and four as near-threatened species. The genus Tsuga exhibits a disjunctive distribution in East Asia (EA), eastern North America (ENA), and western North America (WNA). It is crucial to comprehend the mechanisms underlying these distributional changes and to identify key climate variables to develop effective conservation strategies for Tsuga under future climate scenarios. In this study, we applied the maximum entropy (MaxEnt) model by combining distribution data for Tsuga with abundant pollen fossil data. Our objective was to investigate the climate factors that shape the distribution of Tsuga, identify climate thresholds, and elucidate distribution dynamics in the context of significant climate changes over the past 1070 thousand years (ka). Our findings highlight the pivotal role of precipitation as the key climate factor affecting the distribution of Tsuga. Specifically, in EA, summer precipitation was the key driver, while in North America (NA), winter precipitation exerted greater importance. Moreover, we observed similarities in climatic requirements between Tsuga species in Europe and EA, and declines in summer precipitation and winter temperature were major factors contributing to the extinction of Tsuga species in Europe. Quaternary glacial and interglacial fluctuations exerted substantial impacts on Tsuga distribution dynamics. The disappearance of Tsuga species in the Korean Peninsula may have occurred during the LGM (Last Glacial Maximum). The potential suitable area for Tsuga species in EA expanded during the cold periods, while in NA, it contracted. In the future, climate change may result Tsuga distribution area contraction in both the EA and NA. Our study has identified distinct response patterns of Tsuga in various geographic regions to Quaternary climate change and offers corresponding suggestions for Tsuga conservation. In the future, it will be imperative to prioritize the conservation of natural Tsuga distributions in EA and NA, with a focus on the impacts of precipitation fluctuation on the dynamic distribution of this genus.

Novoa, A., H. Hirsch, M. L. Castillo, S. Canavan, L. González, D. M. Richardson, P. Pyšek, et al. 2023. Genetic and morphological insights into the Carpobrotus hybrid complex around the world. NeoBiota 89: 135–160.

The genus Carpobrotus N.E.Br. comprises between 12 and 25 species, most of which are native to South Africa. Some Carpobrotus species are considered among the most damaging invasive species in coastal dune systems worldwide. In their introduced areas, these species represent a serious threat to native species and significantly impact soil conditions and geochemical processes. Despite being well studied, the taxonomy of Carpobrotus remains problematic, as the genus comprises a complex of species that hybridize easily and are difficult to distinguish from each other. To explore the population genetic structure of invasive Carpobrotus species (i.e., C. acinaciformis and C. edulis) across a significant part of their native and non-native ranges, we sampled 40 populations across Argentina, Italy, New Zealand, Portugal, South Africa, Spain, and the USA. We developed taxon-specific microsatellite markers using a Next Generation Sequencing approach to analyze the population genetic structure and incidence of hybridization in native and non-native regions. We identified three genetically distinct clusters, which are present in both the native and non-native regions. Based on a set of selected morphological characteristics, we found no clear features to identify taxa morphologically. Our results suggest that the most probable sources of global introductions of Carpobrotus species are the Western Cape region of South Africa and the coastline of California. We suggest that management actions targeting Carpobrotus invasions globally should focus on preventing additional introductions from the east coast of South Africa, and on searching for prospective biocontrol agents in the Western Cape region of South Africa.

Zhang, H., W. Guo, and W. Wang. 2023. The dimensionality reductions of environmental variables have a significant effect on the performance of species distribution models. Ecology and Evolution 13.

How to effectively obtain species‐related low‐dimensional data from massive environmental variables has become an urgent problem for species distribution models (SDMs). In this study, we will explore whether dimensionality reduction on environmental variables can improve the predictive performance of SDMs. We first used two linear (i.e., principal component analysis (PCA) and independent components analysis) and two nonlinear (i.e., kernel principal component analysis (KPCA) and uniform manifold approximation and projection) dimensionality reduction techniques (DRTs) to reduce the dimensionality of high‐dimensional environmental data. Then, we established five SDMs based on the environmental variables of dimensionality reduction for 23 real plant species and nine virtual species, and compared the predictive performance of those with the SDMs based on the selected environmental variables through Pearson's correlation coefficient (PCC). In addition, we studied the effects of DRTs, model complexity, and sample size on the predictive performance of SDMs. The predictive performance of SDMs under DRTs other than KPCA is better than using PCC. And the predictive performance of SDMs using linear DRTs is better than using nonlinear DRTs. In addition, using DRTs to deal with environmental variables has no less impact on the predictive performance of SDMs than model complexity and sample size. When the model complexity is at the complex level, PCA can improve the predictive performance of SDMs the most by 2.55% compared with PCC. At the middle level of sample size, the PCA improved the predictive performance of SDMs by 2.68% compared with the PCC. Our study demonstrates that DRTs have a significant effect on the predictive performance of SDMs. Specifically, linear DRTs, especially PCA, are more effective at improving model predictive performance under relatively complex model complexity or large sample sizes.

Issaly, E. A., M. C. Baranzelli, N. Rocamundi, A. M. Ferreiro, L. A. Johnson, A. N. Sérsic, and V. Paiaro. 2023. Too much water under the bridge: unraveling the worldwide invasion of the tree tobacco through genetic and ecological approaches. Biological Invasions.

Understanding how, and from where, invasive species were introduced is critical for revealing the invasive mechanism, explaining the invasion success, and providing crucial insights for effective management. Here, we combined a phylogeographic approach with ecological niche modeling comparisons to elucidate the introduction mode and source of Nicotiana glauca , a native South American species that is now invasive worldwide. We tested three different scenarios based on the invasion source—random native, restricted native, and bridgehead invasive—considering genetic diversity and climatic niche comparisons among native and invaded areas. We found three genetic lineages geographically and climatically differentiated within the native range. Only one of these genetic groups contained the invasive haplotypes, but showed no climatic niche overlap with any invaded area. Conversely, one invaded area located in western South America, with more genetic diversity than other invaded areas but less than the native range, showed climatic niche overlap with almost all other invaded areas worldwide. These findings indicate that N. glauca first likely invaded the southernmost areas beyond its native range, forming a bridgehead invasive source, from which the species subsequently invaded other regions around the world. Invasiveness would have been fostered by changes in the environmental preferences of the species in the bridgehead area, towards drier, colder and less seasonal climates, becoming the actual source of invasion to areas climatically similar throughout the world. The fine scale resolution analyses combining genetic and climatic approaches within the native range were essential to illuminating the introduction scenario of this invasive species.

Ambrosia trifida L. (Asteraceae) – североамериканское однолетнее растение, включенное в перечень карантинных объектов в Европе, в том числе в Российской Федерации и сопредельных странах. Об- суждаются результаты исследований 2017–2021 гг. по выявлению современного распространения и особенностей натурализации этого вида на европейской части России. Центрами массовой натура- лизации А. trifida на исследуемой территории являются Заволжье (Самарская область, юг Татарста- на), Предуралье (Оренбургская область, Башкортостан), Предволжье (запад Саратовской области), Хоперско-Бузулукская равнина (северо-запад Волгоградской области), юго-запад Окско-Донского плоскоместья и Калачская возвышенность (центр и юг Воронежской области). Анклавы в виде на- турализовавшихся популяций отмечены в Брянской и Владимирской областях, а также в городах Казань и Уфа. В дальнейшем можно ожидать распространение A. trifida на большой части европей- ской территории России.