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\"Harrowing journeys of animals and plants-fleeing skyrocketing temperatures and mega-droughts-reported from the frontlines of the greatest migration of species since the Ice Age\"-- Provided by publisher.

Bulrushes of the genus Bolboschoenus are robust, ecologically important sedges occurring in wetlands, including intertidal marshes and mudflats. Despite their importance and multiple serious threats to their habitats, estuarine Bolboschoenus species remain poorly known. We conducted herbarium and field research in order to document historic and current geographic distributions, characterize the habitats, and assess the conservation status of Bolboschoenus species in the Hudson River Estuary, New York, U.S.A. Three species of Bolboschoenus grow in intertidal zones in the Hudson Estuary. Bolboschoenus fluviatilis occurs in the northern, upstream, and freshwater portion of the estuary with multi-year mean surface salinities of 0.078-2.0 ppt. Bolboschoenus robustus occupies the southernmost, downstream, and brackish to saline portion of the estuary with salinities of 4.9-16 ppt. Bolboschoenus novae-angliae occurs in the slightly to strongly brackish region between the other two species with salinities of 1.8-8.0 ppt. The geographic ranges of B. fluviatilis and B. robustus do not overlap, but B. novae-angliae has short zones of sympatry with each of the other two species. Syntopy of B. novae-angliae with each of the other two species is rare. In the Hudson Estuary, B. fluviatilis is secure, but B. novae-angliae and B. robustus are critically imperiled. Threats to future survival of Bolboschoenus species in the Hudson Estuary include competition from invasive plant species (especially Phragmites australis), eutrophication resulting from excess nutrient pollution, and habitat destruction. Our data and analyses provide critical new information for management of existing environmental problems and planned habitat restoration efforts in the Hudson River Estuary.

\"Alexander von Humboldt (1769-1859) was an intrepid explorer and the most famous scientist of his age. His life was packed with adventure and discovery, whether he was climbing volcanoes in the Andes, racing through anthrax-infected Siberia, or publishing groundbreaking bestsellers. Ahead of his time, he recognized nature as an interdependent whole and he saw before anyone else that humankind was on a path to destroy it\"-- Provided by publisher.

Oxalis debilis Kunth, an invasive plant native to South America, has already spread extensively throughout various regions in China including West China, East China, Central China, and South China. It poses a certain degree of damage to the local ecosystem and demonstrates significant invasive potential. Utilizing distribution information along with environmental variables such as bioclimate, soil factors, elevation, and UV-B radiation, the MaxEnt model combined with ArcGIS was employed to forecast the potential distribution of O. debilis in China. The ROC curve was employed to assess the accuracy of the model, while the jackknife test was utilized to identify dominant environmental variables and determine their optimal values. The simulated AUC value was 0.946 ± 0.004, and the predicted results exhibited a remarkable concordance with the actual outcomes, thereby indicating that the Maxent model demonstrated a high level of confidence in its predictive capabilities. The potential distribution of O. debilis in China spanned 18,914,237 km[sup.2] , accounting for 19.70% of the total land area. This distribution was primarily observed in East, Central, and South China, with Guangdong, Guangxi, and Guizhou being identified as highly suitable habitats for O. debilis. Furthermore, it was observed that the distribution of O. debilis is primarily influenced by environmental variables such as the precipitation of the driest month, the monthly diurnal range, the mean temperature of the wettest quarter, and the isothermality. The findings can serve as a valuable point of reference for the prevention and monitoring of O. debilis spread, thereby contributing to the protection of China’s agricultural, forestry, and ecological environments. It is imperative to acknowledge the hazards associated with O. debilis, closely monitor its invasion, and prevent uncontrolled dissemination.

Pinus trifolia Miki 1939 (Pinaceae) was originally proposed based on seed cones from the upper Miocene of Aichi and Gifu Prefectures, central Japan. However, before the publication of P. trifolia, a different name (Pinus fujiii (Yasui) Miki) was given to a female cone with the same morphology. On the other hand, P. fujiii auct. non (Yasui) Miki has been used for seed cones with different morphologies from Yasui's holotype, i.e., apophyses arranged in 5:8 parastichies and a perexcentromucronate slightly-pointed umbo. As a result of re-examination on the Miki and Yasui specimens, we concluded that P. trifolia was a synonym for P. fujiii and proposed here Pinus mikii sp. nov. for cones assigned to P. fujiii auct. non (Yasui) Miki. We also emended the diagnosis of P. fujiii based on these specimens. Pinus fujiii is characterized by a large female cone in which the apophyses with a centromucronate prickle-like umbo are arranged in 8:13 parastichies, and deciduous seed wings. These characters suggest that P. fujiii belongs to the section Trifoliae of the subgenus Pinus, which is now restricted to North and Central America and the Caribbean islands. Fossil data suggest that the P. fujiii lineage firstly appeared in Japan around the Eocene/Oligocene boundary. We speculate that the P. fujiii lineage might have moved southward to Japan from a refugium located elsewhere in high-latitude areas in response to the late Eocene cooling event, as occurred with other Trifoliae species in North America.

The identity of the dominant root-associated microbial symbionts in a forest determines the ability of trees to access limiting nutrients from atmospheric or soil pools1,2, sequester carbon3,4 and withstand the effects of climate change5,6. Characterizing the global distribution of these symbioses and identifying the factors that control this distribution are thus integral to understanding the present and future functioning of forest ecosystems. Here we generate a spatially explicit global map of the symbiotic status of forests, using a database of over 1.1 million forest inventory plots that collectively contain over 28,000 tree species. Our analyses indicate that climate variables—in particular, climatically controlled variation in the rate of decomposition—are the primary drivers of the global distribution of major symbioses. We estimate that ectomycorrhizal trees, which represent only 2% of all plant species7, constitute approximately 60% of tree stems on Earth. Ectomycorrhizal symbiosis dominates forests in which seasonally cold and dry climates inhibit decomposition, and is the predominant form of symbiosis at high latitudes and elevation. By contrast, arbuscular mycorrhizal trees dominate in aseasonal, warm tropical forests, and occur with ectomycorrhizal trees in temperate biomes in which seasonally warm-and-wet climates enhance decomposition. Continental transitions between forests dominated by ectomycorrhizal or arbuscular mycorrhizal trees occur relatively abruptly along climate-driven decomposition gradients; these transitions are probably caused by positive feedback effects between plants and microorganisms. Symbiotic nitrogen fixers—which are insensitive to climatic controls on decomposition (compared with mycorrhizal fungi)—are most abundant in arid biomes with alkaline soils and high maximum temperatures. The climatically driven global symbiosis gradient that we document provides a spatially explicit quantitative understanding of microbial symbioses at the global scale, and demonstrates the critical role of microbial mutualisms in shaping the distribution of plant species.

This work presents an updated list of the species belonging to the genus Phaseolus following its definition of 1978; it is the outcome of the study of eighty-six herbaria and forty-one explorations in the field in the period 1978–2019. There are currently eighty-one species, all of them native to the Americas, most of them distributed north of Panama (the genus is a migrant into South America), and half of them being known by very few records. They thrive in warm to mild temperate, seasonally dry, open forest, with rains under favorable temperature, from sea level up to 3,000 m. The recent increase in the number of recognized species is due to the endemic ones; this in combination with few unclassified specimens may indicate that the total number of species is not final yet, and that field work will be rewarding. Este trabajo presenta una lista actualizada de las especies que pertenecen al género Phaseolus según la definición de 1978. Es el resultado del estudio de ochenta y seis Herbarios y de cuarenta y una bioprospecciones en el campo durante el período 1978–2019. Hay ochenta y una especies hasta la fecha, siendo todas parte de la flora americana, la mayoría distribuida al norte de Panamá (el género es un migrante en Suramérica), y más de la mitad conocida por sólo muy pocas poblaciones. Crecen en climas cálidos a templados moderados, con estación seca y con las lluvias durante el período de temperaturas favorables, en bosques abiertos desde el nivel del mar hasta los 3,000 m. El crecimiento reciente en el número de especies se debe al descubrimiento de especies endémicas. Esta situación combinada con la presencia de algunos especímenes aún por identificar puede indicar que el número total de especies no sea definitivo, y que el trabajo de campo aún puede ser muy gratificante. Ce travail présente une liste actualisée des espèces appartenant au genre Phaseolus suivant la définition adoptée en 1978. C'est le résultat de l'étude de quatre-vingt-six Herbiers et de quarante et une prospections. Quatre-vingt-une espèces sont actuellement recensées, elles font toutes partie de la flore américaine. La majeure quantité des espèces ont leur distribution au nord du Panama (le genre est un migrant en Amérique du Sud), y plus de la moitié des espèces sont connues seulement par quelques populations. Elles se trouvent dans des climats chauds à modérément tempérés, avec une saison sèche et les pluies distribuées pendant la période de températures favorables. Elles font partie de forêts ouvertes, depuis le niveau de la mer jusqu'à 3,000 m. L'accroissement récent du nombre d'espèces est dû à la découverte d'espèces endémiques. Cette situation combinée à la présence de quelques spécimens encore non identifiés peut indiquer que le nombre total d'espèces n'est pas définitif, et que le travail de terrain peut encore être très positif.

Copyright Lars Söderström et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CCBY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.