Hugo Gunckel Lüer

Without appropriate and ongoing management interventions, weeds will continue to economically and environmentally disadvantage agricultural and natural ecosystems. For these management strategies to have long‐term sustained success, they need to carefully consider the biological aspects of the targeted weed. These strategies will also need to consider potential adaptations evolved by the targeted weed in response to a range of selection pressures imposed by anthropogenetic factors, climate change, changing environmental conditions, and inappropriate or unsuccessful management regimes. One group of weeds that has been observed to readily adapt to a wide range of conditions and has shown considerable challenges in their management is invasive grasses. Adding to these challenges is that several invasive grasses have also developed resistance to a range of herbicide modes of action, which, to date, has been one of the most commonly used methods of control. To address these challenges, this review explores the biology and ecology of the globally invasive annuals Echinochloa crus‐galli (Barnyard grass) and Panicum capillare (Witchgrass), and the perennial Sorghum halepense (Johnson grass) to identify (i) the most suitable management options for their control and (ii) potential research gaps that may assist in the future management direction of these species. Based on the findings of this review, it is clear that an integrated management approach that targets different aspects of the plant's biology, in combination with early detection and treatment and ongoing surveillance, is necessary for the long‐term control of these species. Although a combination of methods appears promising, further investigation still is required to evaluate their efficiency and long‐term success in a changing environment, all of which are further discussed within this review.

Accessing the rich biodiversity in tropical ecosystems has been of great interest to scientists across the globe. While several species have been underutilized despite their wide distribution, many others are faced with continuous population decline across their native range. Here, we amassed occurrence data and environmental variables to estimate the spatial distribution and habitat suitability of six important Pelargonium species whose conservation status in South Africa has been of concern. These were combined and used to project the future habitats under 2 Global Climate Models (GCMs) and 2 Scenarios (RCP 4.5 & 8.5). We overlayed our area maps and conducted a gap analysis to identify priority areas for the conservation of our focal species. Results showed a distribution pattern driven by temperature and precipitation, and unstable suitable areas by the years 2050 and 2070. Five temperature and precipitation variables (Bio2, Bio4, Bio12, Bio14, and Bio18) were identified as primary contributors to the habitat suitability of the selected Pelargonium species. Our model evaluation demonstrated a strong performance, with an AUC score >0.8, providing robust support for its replicability in monitoring the spatial distribution of other related taxa. We identified key areas for conservation activities in a bid to expand the current known habitats of the species in focus. While we leveraged SDM approach for explaining the area of occupancy and the spatial extent of Pelargonium species across in South Africa, we posit that attention should be drawn to the preservation of the remaining populations of the species and their associated habitats, towards mitigating their extinction.

Abstract The Neotropics have been host to a myriad of geological and climatic events that have shaped the biodiversity present in the region. Bromeliaceae forms one of the most prominent components of the Neotropical flora, being considered the largest group nearly exclusive to the Americas, with almost 4000 species divided into eight subfamilies. Here, we utilize a new time-calibrated molecular phylogeny including 1268 bromeliad taxa and integrate habitat and morphological data to answer the following questions: (i) Are bromeliad subfamilies monophyletic, and did Neogene and Quaternary events in South America coincide with their divergence? (ii) Did naked seeds of berry-fruited species, epiphytic growth, and climatic factors increase bromeliad diversification? Our analysis reconstructed a new topology concerning some recently diverged lineages, with the genus Bromelia emerging as the sister group of a clade including all remaining Bromelioideae lineages + Puyoideae. Miocene events possibly triggered the diversification of bromeliads after a long period of stasis during the Palaeogene. We hypothesize that the morphological shift between Bromelia and Bromelioideae (except Bromelia) is related to the colonization of a new high-elevation environment by Puyoideae in the Andes. Additionally, our results show that naked seeds and the epiphytic growth form positively influence diversification rate, while precipitation, temperature, and elevation have a negative influence. We emphasize the importance of considering a variety of morphological and ecological features to enhance our understanding of bromeliad evolution.

AbstractThe availability of valid, non-biased species occurrence data has always been a major challenge for biodiversity research and modelling studies. Data from open-source databases or remote sensing are promising approaches to increase the availability of species occurrence data. However, these data may contain spatial, temporal, and taxonomic biases or require ground truthing. In recent years, social media has received attention for its contribution to species occurrence data sampling and ground truthing approaches. The wide reach of social media platforms allows for rapid and large-scale analyses.Here we introduce a novel Instagram ground truthing approach to validate the occurrence mapping of Nothofaguspumilio across its entire distribution range. The treeline species of the southern Andes has been extensively studied in small-scale studies, but large-scale modelling approaches are largely missing due to limited accessibility to treeline sites resulting in a lack of occurrence data. The content posted on the social media platform Instagram consists of images and videos in which the species N.pumilio and its location can be identified. By searching for suitable posts using hashtags and location tags, we created 1238 Instagram ground truthing points. We compared the performance of our dataset with open-source data from the Global Biodiversity Information Facility (GBIF) through visual, quantitative, and bias analyses, acknowledging that both social media-based and Citizen Science data are subject to sampling and spatial biases due to collection in human-accessible areas. The Instagram ground truthing points were subsequently used to validate remote sensing occurrence data, generated using Sentinel-2 level 2A data and Supervised Classification. The combined approach – Instagram ground truthing and remote sensing – allows for the collection of occurrence data over the entire latitudinal range of N.pumilio, covering approximately 2000 km.HighlightsThe use of social media content provides potentially important contributions to species occurrence data sampling and ground truthingIn our study we introduce a novel ground truthing approach for species occurrence data sampling based on Instagram dataInstagram ground truthing points, combined with Supervised Classification generate species occurrence data of Nothofaguspumilio over its entire distribution range in the southern AndesThe performance of the Instagram ground truthing points is evaluated by comparison with existing data from the GBIF database.Our Instagram ground truthing approach demonstrates a new way of sampling species occurrence data and can be applied to other suitable species and study areas.

Abstract After many decades of effective control of stem rust caused by the Puccinia graminis f.sp. tritici, (hereafter Pgt) the reported emergence of race TTKSK/Ug99 of Pgt in Uganda reignited concerns about epidemics worldwide because ∼90% of world wheat cultivars had no resistance to the new race. Since it was initially detected in Uganda in 1998, Ug99 variants have now been identified in thirteen countries in Africa and the Middle East. Stem rust has been a major problem in the past, and concern is increasing about the risk of return to Central and East Asia. Whilst control programs in North America and Europe relied on the use of resistant cultivars in combination with eradication of barberry (Berberis spp.), the alternate host required for the stem rust pathogen to complete its full lifecycle, the focus in East Asia was principally on the use of resistant wheat cultivars. Here, we investigate potential airborne transmission pathways for stem rust outbreaks in the Middle East to reach East Asia using an integrated modelling framework combining estimates of fungal spore deposition from an atmospheric dispersion model, environmental suitability for spore germination, and crop calendar information. We consider the role of mountain ranges in restricting transmission pathways, and we incorporate a representation of a generic barberry species into the lifecycle. We find viable transmission pathways to East Asia from the Middle East to the north via Central Asia and to the south via South Asia and that an initial infection in the Middle East could persist in East Asia for up to three years due to the presence of the alternate host. Our results indicate the need for further assessment of barberry species distributions in East Asia and appropriate methods for targeted surveillance and mitigation strategies should stem rust incidence increase in the Middle East region.

In this study, we explored the distributions of grass genera in the Southern Cone (SC) of South America, applying several phylogenetic diversity (PD) metrics and randomization tests. Grasses appear to have been present in South America since their early evolution as tropical understory species more than 60 Ma. During the course of evolution, grasses have adapted to all terrestrial biomes and become one of the most successful plant families on earth. At present, the SC contains nearly all terrestrial biomes and a wide range of humid to arid ecoregions. Analyzing 126.514 point occurrences and four plastid markers for 148 genera (91% of the native grass genera), we found that tropical humid regions hold the highest PD, with no observed bias in branch lengths. These results indicate that niche conservatism dominates the diversity pattern of grasses in the SC. We found significantly low PD in the Dry Chaco and in the Patagonian Steppe, which suggest ecological filtering in both warm and cold arid regions. The Patagonian Steppe also holds significantly longer branches than expected by chance, as the native grass flora is mainly composed of distantly related Pooideae genera with a northern hemisphere origin. Short branches are found in the Uruguayan Savanna, suggesting that these grasslands could be a cradle for grass diversity within the SC. The dated phylogeny supported the current view of a relatively recent evolution of the family within the SC, with most diversification taking place from the middle Miocene and onwards.

It would be advantageous to grow legume forage crops in order to increase the productivity and sustainability of sloped croplands in Hamkyongbukdo. In particular, the identification of potential cultivation areas for alfalfa in the given region could aid decision-making on policies and management related to forage crop production in the future. This study aimed to analyze the climate suitability of alfalfa in Hamkyongbukdo under current and future climate conditions using the Fuzzy Union model. The climate suitability predicted by the Fuzzy Union model was compared with the actual alfalfa cultivation area in the northern United States. Climate data obtained from 11 global climate models were used as input data for calculation of climate suitability in the study region to examine the uncertainty of projections under future climate conditions. The area where the climate suitability index was greater than a threshold value (22.6) explained about 44% of the variation in actual alfalfa cultivation areas by state in the northern United States. The climatic suitability of alfalfa was projected to decrease in most areas of Hamkyongbukdo under future climate scenarios. The climatic suitability in Onseong and Gyeongwon County was analyzed to be over 88 in the current climate conditions. However, it was projected to decrease by about 66% in the given areas by the 2090s. Our study illustrated that the impact of climate change on suitable cultivation areas was highly variable when different climate data were used as inputs to the Fuzzy Union model. Still, the ensemble of the climate suitability projections for alfalfa was projected to decrease considerably due to summer depression in Hamkyongbukdo. It would be advantageous to predict suitable cultivation areas by adding soil conditions or to predict the climate suitability of other leguminous crops such as hairy vetch, which merits further studies.

Orsillus depressus , a circum-mediterranean species of seed bug that lives on several genera and species of Cupressaceae is considered a pest of these trees, has recently been recorded for the first time in America, in Argentina. As the western records of O. depressus are close to endemic Cupressaceae forests from the Andean Region, our attention is drawn to the possible risk of colonization and establishment of O. depressus on these forests, where three endemic monotipic genera are found: Austrocedrus chilensis , Fitzroya cupressoides and Pilgerodendron uviferum . Maxent Models for present and future scenarios, and Minimum Volume Ellipsoids were used, and natural pathways were explored. Orsillus depressus has shown a high adaptive capacity to environments with different climates, and considering the models predictions, there are large suitable areas for its establishment in southern Argentina and Chile. Also, the climatic space O. depressus occupies is small and in part new, and an expansion should be expected. Moreover, multiple natural pathways were recognized that would allow its ingression in areas highly suitable with endemic Cupressaceae forests.

Present-day geographic and phylogenetic patterns often reflect the geological and climatic history of the planet. Neontological distribution data are often sufficient to unravel a lineage’s biogeographic history, yet ancestral range inferences can be at odds with fossil evidence. Here, I use the fossilized birth–death process and the dispersal–extinction cladogenesis model to jointly infer the dated phylogeny and range evolution of the tree fern order Cyatheales. I use data for 101 fossil and 442 extant tree ferns to reconstruct the biogeographic history of the group over the last 220 million years. Fossil-aware reconstructions evince a prolonged occupancy of Laurasia over the Triassic–Cretaceous by Cyathealean tree ferns, which is evident in the fossil record but hidden from analyses relying on neontological data alone. Nonetheless, fossil-aware reconstructions are affected by uncertainty in fossils’ phylogenetic placement, taphonomic biases, and specimen sampling and are sensitive to interpretation of paleodistributions and how these are scored. The present results highlight the need and challenges of incorporating fossils into joint inferences of phylogeny and biogeography to improve the reliability of ancestral geographic range estimation.

Maqui ( Aristotelia chilensis ) is a small tree endemic to Patagonia. It is currently being actively domesticated for its edible berries, which have high polyphenol content and anti-oxidant capability. However, little is known about its population structure and evolutionary history, information which is useful for the design of effective conservation and domestication strategies. Based on information from other species, we hypothesize that genetic diversity in maqui is higher in northern population and decrease to the South, associated with past migration patterns and as a result has well-structured populations. To explore the genetic diversity of 14 populations (183 samples) of this species, that represent the geographic distribution of the species in Chile we used 13 polymorphic microsatellite markers. Clusters based on Bayesian genetic and spatial structure analyses were used to reconstruct patterns of phylogeographic and demographic history. We found that maqui populations are well-structured, with a substantial reduction of genetic diversity from north to south. The lowest diversity was found in areas that were once covered by ice during the quaternary glaciation. In conclusion, three main genetic groups were revealed by Structure analysis, and genetic diversity reduction from its northern limit in central Chile to the Patagonian region was found, suggesting that an active recolonization process took place during the last few millennia following the last glacial period. These results will help to define accessions from different regions and contribute to support conservation and domestication initiatives.