Ongoing climate change is having profound impacts on the growth and distribution of trees worldwide. However, there remain substantial gaps in our understanding of how environmental factors influence tree-growth responses to climate at larger scales, which is critical for identifying regions susceptible to the impacts of climate change. In this study, we aimed to reveal the main environmental factors that determine the spatial heterogeneity of tree-growth sensitivity to temperature, precipitation, and drought across temperate forests in Northeast Asia (30-45 degrees N, 124-146 degrees E). Utilising an extensive tree-ring network of 101 chronologies of 22 tree species, across 79 sites, we found that local climate, and especially climate water deficit, plays a dominant role in shaping the spatial heterogeneity of tree-growth sensitivity, while geospatial variables were less important. Our analysis revealed a pervasive pattern of increased tree susceptibility to drought across Northeast Asian forests. Specifically, at sites experiencing high climate water deficit, tree growth was consistently reduced across both broadleaved and coniferous species under conditions of low precipitation, elevated temperatures, and increased dryness during the growing season. Our findings suggest that ongoing climate warming may further negatively affect tree-growth performance, especially at drier sites, across Northeast Asian forests.

Temperate deciduous forests of North America, west Eurasia, and east Eurasia share a common origin but were later separated by major geographic barriers. Here, we examine their diverging biodiversity and evolutionary patterns by analyzing floristic richness, phylogenetic turnover, and community evolutionary distinctiveness (CED). We analyzed ~ 9600 vegetation plots across the Northern Hemisphere to calculate species rarefaction curves, within‐ and between‐region phylogenetic turnover, and CED to assess the presence of evolutionarily isolated lineages within communities. We then modeled CED as a function of present‐day and last glacial maximum (LGM) macro‐environmental factors using boosted regression trees (BRTs). East Eurasian forests had the highest floristic richness, especially among woody species, while west Eurasia featured the richest herbaceous component. Within‐region phylogenetic turnover was lowest in east Eurasia, followed by North America and west Eurasia. Between‐region phylogenetic turnover was highest between west Eurasia and east Eurasia, and lowest for North America–east Eurasia. North America ranked highest in CED, followed by east Eurasia and west Eurasia. The BRTs revealed contrasting effects of the current and LGM climate on CED across regions. Present precipitation seasonality had a striking negative impact on CED in east Eurasia, whereas temperature seasonality had a strong negative effect in west Eurasia. East Eurasia's exceptional woody, gymnosperm, and fern diversity may reflect the region's long‐term climatic and geological stability, which has allowed the persistence and diversification of ancient lineages. Meanwhile, the pronounced evolutionary distinctiveness of North American forests may be linked to more intense climatic and tectonic shifts over both Quaternary and deeper timescales. These findings highlight the unique evolutionary legacies of the temperate deciduous biome and call for future research that expands geographic and climatic coverage to capture the full diversity of temperate deciduous forests worldwide.

The first complete and updated checklist of vascular plants of Asian Russia is compiled. It is based on “Checklist of Flora of Asian Russia: Vascular Plants” (Baikov 2012) but incorporates numerous floristic, taxonomic and nomenclatural novelties. The territorial scope of the checklist is constituted by three federal districts of Russia (Ural, Siberian and Far Eastern). Sverdlovsk Oblast and Chelyabinsk Oblast are included in the checklist for the first time. Native, alien, naturalized, casual aliens and frequently cultivated (not found outside cultivation) taxa are included. The monotypic species concept is consistently followed. Species and nothospecies (interspecific hybrids) are distinguished; very closely related taxa are grouped into species aggregates. The generic concept of the Catalogue of Life (COL) is accepted to avoid conflicts between contrasting taxonomies. For accepted species, references are made to the corresponding taxonomy in Baikov (2012), COL and Plants of the World Online (POWO); in case of name changes, synonyms are provided. Further synonyms are added when deemed necessary to indicate taxonomic circumscriptions. Most important changes in nomenclature and taxonomy, recently described taxa and additions to the flora of Asian Russia are annotated. The occurrence and residence status (native, alien, cultivated) of species in 13 botanical provinces of Asian Russia are given. The vascular flora of Asian Russia includes 8251 species and 489 hybrids. Of these, 7340 species are native (+420 hybrids), 684 are alien (+46 hybrids) and 227 are cultivated (+23 hybrids). Altogether, 3683 species are assigned to one of 1156 species aggregates. Among native species, 1235 are endemic to Asian Russia; 252 species are included in the Red Data Book of the Russian Federation. The whole vascular flora of Asian Russia is classified into 165 families, 1199 genera and 9 nothogenera. According to our estimations, the floristic richness of Asian Russia comprises 73.3 % of the Russian flora.

The vegetation of the Kuril Islands remains insufficiently explored due to their remote location and harsh environment. Understanding the factors that influence vegetation distribution in this extensive volcanic chain of islands, spanning over a thousand kilometers, is important for global biogeography. Our paper presents the first vegetation map of Kunashir Island from the Kuril archipelago, compiled using Sentinel-2 medium-resolution multispectral satellite imagery, incorporating original field research data and the Random Forest machine-learning algorithm. The temperate broad-leaved forests are mainly composed of Acer mono subsp. mayrii and Quercus mongolica, predominantly limited to the southwestern coast, and true-boreal dark-coniferous Abies sachalinensis–Picea jezoensis forests located in the northeast part of Kunashir. The vegetation distribution pattern is associated with the warming effect of the Soja current on the east coast of Kunashir Island and the cooling effect of the Kuril current on the west coast. Kunashir's vegetation displays features of an ecotone between temperate and boreal zones. Still, the boundary between these zones should be drawn within the island, rather than between Kunashir and Hokkaido or Kunashir and Iturup, as suggested in some previous biogeographic generalizations.

The incorrect syntaxon names were mentioned in the original article (Krestov et al. 2023). The association "Athyrio–Pinetum koraiensis (validated in this paper)" was indicated as a typical element for the alliance Tilio amurensis– Pinion koraiensis. However, this association was described under a different name: Diplazio sibirici–Pinetum koraiensis Kim ex Krestov, Dzizyurova et Korznikov 2023. Here, we validate the alliance Tilio amurensis–Pinion koraiensis all. nov., holotypus hoc loco – Diplazio sibirici–Pinetum koraiensis Kim ex Krestov, Dzizyurova et Korznikov 2023 (Krestov et al. 2023), the full diagnosis is on page 121 in Krestov et al. (2006). We also validate the order Tilio amurensis–Pinetalia koraiensis ord. nov., holotypus hoc loco – Tilio amurensis–Pinion koraiensis (validated above); the full diagnosis is on pages 117–118 in Krestov et al. (2006). We apologise for any confusion caused.

Betula davurica and deciduous Quercus forests are among the principal forest types in Northeast Asia. They are found throughout continental Northeast Asia and in some mountainous regions of Central Honshu and eastern Hokkaido in the Japanese Archipelago. B. davurica-Quercus crispula forests in Japan are significant for understanding the phytogeography of Japan and Northeast Asia. However, their relationships with B. davurica-Quercus mongolica forests in continental Northeast Asia remain poorly understood. We compared the species composition of B. davurica-Q. crispula forests of Japan, with those of Q. crispula dominant forests and B. davurica-Q. mongolica forests using phytosociological methods. The results suggested that B. davurica-Q. crispula forests of Japan had a significant number of species common to the order Lespedezo bicoloris-Quercetalia mongolicae and the class Querco mongolicae-Betuletea davuricae in continental Northeast Asia than in other associations in Japan. Furthermore, our results showed that associations between B. davurica and Q. crispula forests in Central Honshu and Hokkaido are related to different orders in continental Northeast Asia. The relations of the associations between Japan and the continent are considered to have been caused by the environmental similarities, the histories of taxa, and the changes in vegetation distribution. (c) 2023 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Spruce taiga forests in Northeast Asia are of great economic and conservation importance. Continued climate warming may cause profound changes in their distribution. We use prognostic and retrospective species distribution models based on the Random Forest machine learning method to estimate the potential range change of the dominant taiga conifer Jezo spruce (Picea jezoensis (Siebold & Zucc.) Carrière) for the year 2070 climate warming scenarios and for past climate epochs–the Last Glacial Maximum (LGM) (~21,000 years before present) and the mid-Holocene Climatic Optimum (MHO) (~7000 years before the present) using the MIROC-ESM and CCSM4 climate models. The current suitable climatic conditions for P. jezoensis are estimated to be 500,000 km2. Both climatic models show similar trends in past and future ranges but provide different quantitative areal estimates. During the LGM, the main part of the species range was located much further south than today at 35–45° N. Projected climate warming will cause a greater change in the distributional range of P. jezoensis than has occurred since the MHO. Overlapping climatic ranges at different times show that the Changbai Mountains, the central parts of the Japanese Alps, Hokkaido, and the Sikhote-Alin Mountains will remain suitable refugia for Jezo spruce until 2070. The establishment of artificial forest stands of P. jezoensis and intraspecific taxa in the future climate-acceptable regions may be important for the preservation of genetic diversity.

This paper presents a characterization of the syntaxa of zonal dark coniferous forests dominated by Abies nephrolepis, A. sachalinensis, Picea jezoensis, P. glehnii, and P. obovata of the class Vaccinio-Piceetea Br.-Bl. in Br.-Bl. et al. 1939 and the order Abieti veitchii–Piceetalia jezoensis Miyawaki, Ohba, Okuda, Nakayama et Fujiwara 1968. The order Pinetalia pumilae Suzuki 1964, which unites thickets of Siberian dwarf pine (Pinus pumila), is also included. Each syntaxon is presented with its diagnostic taxa list, distribution, and habitat conditions. Furthermore, we validate the names of one alliance, two associations, and two subassociations of dark coniferous forests, because these syntaxa were described invalidly earlier (Vegetation…, 1988; Krestov, Nakamura 2002). Ass. Piceetum glehnii Nakamura ex Korznikov et Krestov ass. nov. Diagnostic species: Picea glehnii, Menziesia pentandra, Pogonatum japonicum (Krestov, Nakamura, 2002). Synonyms: Piceetum glehnii Suzuki ex Nakamura in Miyawaki 1988 nom. inval. (3o, 5a); Piceetum glehnii Suzuki ex Krestov et Nakamura 2002 nom. inval. (3o, 5a). Subass. Piceetum glehnii typicum Korznikov et Krestov subass. nov. Diagnostic species: Arachniodes mutica, Rhododendron brachycarpum, Scapania sp. (Krestov, Nakamura, 2002). Synonyms: Piceetum glehnii subass. von Rhododendron brachycarpum Nakamura in Miyawaki 1988 (orig. name) nom. inval. (3e, 3o, 5); Piceetum glehnii rhododendretosum brachycarpi Nakamura ex Krestov et Nakamura 2002 nom. inval. (3o, 4a, 5) Subass. Piceetum glehnii sasetosum kurilense Krestov et Nakamura ex Korznikov et Krestov subass. nov. Diagnostic species: Sasa kurilensis (Krestov, Nakamura, 2002). Synonyms: Piceetum glehnii sasetosum kurilense Krestov et Nakamura 2002 nom. inval. (4a). Ass. Piceo jezoensis–Abietetum sachalinensis Ohba ex Korznikov et Krestov ass. nov. Diagnostic species: Acer mono subsp. mayrii, Galium kamtschaticum, Hydrangea petiolaris, Kalopanax septemlobus, Toxicodendron orientale, Trillium smallii, Prunus ssiori, Quercus mongolica (Krestov, Nakamura, 2002). Synonyms: Piceo jezoensis–Abietetum sachalinensis Ohba 1967 nom. inval. (2b); Piceo jezoensis–Abietetum sachalinensis Ohba ex Nakamura in Miyawaki 1988 nom. inval (3o, 5a); Piceo jezoensis–Abietetum sachalinensis Ohba ex Krestov et Nakamura 2002 nom. inval. (3f, 3o, 5a, 16). All. Pino pumilae–Piceion jezoensis Krestov et Nakamura ex Korznikov et Krestov all. nov. Diagnostic species: Allium ochotense, Betula pendula subsp. mandshurica, Equisetum sylvaticum, Lonicera chamissoi, Pinus pumila, Pyrola asarifolia subsp. asarifolia, Sorbus aucuparia subsp. glabrata, Sorbus sambucifolia, Spiraea betulifolia var. aemiliana (Krestov, Nakamura, 2002). Synonyms: Pino pumilae–Piceion jezoensis Krestov et Nakamura 2002 nom. inval. (3o, 5a). Two alliances and two suballiances of larch forests, which belong to the class Vaccinio-Piceetea, are also validated in this paper. These names were previously published invalidly (Krestov et al., 2009; Sinelnikova, 2016). All. Rhododendro aurei–Laricion cajanderi Krestov, Ermakov, Osipov et Nakamura ex Korznikov et Krestov all. nov. hoc loco Diagnostic species: Pinus pumila, Spiraea betulifolia var. aemiliana, Rhododendron aureum (Krestov et al., 2009). Synonyms: Rhododendro aurei–Laricion cajanderi Krestov, Ermakov, Osipov, Nakamura 2009 nom. inval. (3f). Suball. Junipero sibiricae–Laricenion cajanderi Krestov, Ermakov, Osipov et Nakamura ex Korznikov et Krestov suball. nov. Diagnostic species: Carex pallida, Chamaenerion angustifolium, Equisetum pratense, Juniperus sibirica, Lathyrus pilosus, Pyrola incarnata, Solidago decurrens (Krestov et al., 2009). Synonyms:Junipero sibiricae–Laricenion cajanderi Krestov, Ermakov, Osipov et Nakamura 2009 nom. inv. (4a, 5a, 17). All. Roso acicularis–Laricion cajanderi Sinelnikova ex Korznikov et Krestov all. nov. Diagnostic species: Betula platyphylla, Calamagrostis langsdorffii, Chamaenerion angustifolium, Equisetum pratense, Galium boreale, Larix cajanderi, Ribes triste, Rosa acicularis, Rubus arcticus (Sinelnikova, 2016). Synonyms: Roso acicularis–Laricion cajanderi Sinelnikova 2016 nom. inval. (3o, 5a). The current phytosociological diversity of dark coniferous forests in the region includes one order, three alliances, and 17 associations. In further development of the Vaccinio-Piceetea classification system, we propose dividing the azonal subalpine forests from the temperate zone and the zonal boreal forests into two orders: the order Abieti veitchii–Piceetalia jezoensis s. str. for the temperate zone in Japan and Korea, and a new order for the boreal zone. The order Vaccinio–Pinetalia pumilae Suzuki 1964, which includes the alliance Vaccinio–Pinion pumilae Suzuki 1964 and two associations, Vaccinio–Pinetum pumilae Maeda and Shimazaki ex Suzuki 1966, and Ledo–Pinetum pumilae Kobayashi 1967, unites communities dominated by Pinus pumila. The syntaxonomical concept of the order Vaccinio–Pinetalia pumilae was established based on vegetation data from Japan (Kobayashi, 1967; 1971) and should be updated with vegetation relevés from the Russian Far East.

We validate the name Quercetea mongolicae and 56 subordinated syntaxa of broadleaved and mixed forests from the Far East which were published invalidly. We suggest a new syntaxonomical decision to consider the order Lespedezo bicoloris- Quercetalia mongolicae in the class Quercetea mongolicae instead of Querco mongolicae– Betuletea davuricae Ermakov 1997.

The use of drone-borne imagery for tree recognition holds high potential in forestry and ecological studies. Accurate species identification and crown delineation are essential for tasks such as species mapping and ecological assessments. In this study, we compared the results of tree crown recognition across three neural networks using high-resolution optical imagery captured by an affordable drone with an RGB camera. The tasks included the detection of two evergreen coniferous tree species using the YOLOv8 neural network, the semantic segmentation of tree crowns using the U-Net neural network, and the instance segmentation of individual tree crowns using the Mask R-CNN neural network. The evaluation highlighted the strengths and limitations of each method. YOLOv8 demonstrated effective multiple-object detection (F1-score—0.990, overall accuracy (OA)—0.981), enabling detailed analysis of species distribution. U-Net achieved less accurate pixel-level segmentation for both species (F1-score—0.981, OA—0.963). Mask R-CNN provided precise instance-level segmentation, but with lower accuracy (F1-score—0.902, OA—0.822). The choice of a tree crown recognition method should align with the specific research goals. Although YOLOv8 and U-Net are suitable for mapping and species distribution assessments, Mask R-CNN offers more detailed information regarding individual tree crowns. Researchers should carefully consider their objectives and the required level of accuracy when selecting a recognition method. Solving practical problems related to tree recognition requires a multi-step process involving collaboration among experts with diverse skills and experiences, adopting a biology- and landscape-oriented approach when applying remote sensing methods to enhance recognition results. We recommend capturing images in cloudy weather to increase species recognition accuracy. Additionally, it is advisable to consider phenological features when selecting optimal seasons, such as early spring or late autumn, for distinguishing evergreen conifers in boreal or temperate zones.

Background: Pinus koraiensis Siebold & Zucc. (Korean pine) is a key species of the mixed cold temperate forests of Northeast Asia. Current climate change can significantly worsen the quality of P. koraiensis habitats and therefore lead to a large-scale structural and functional transformation of the East Asian mixed forests. We built a species distribution model (SDM) for P. koraiensis using the random forest classifier - a versatile machine learning algorithm, to discover overlap areas of potential species occurrence in the climate condition of the Last Glacial Maximum (similar to 21,000 year before present) and in the projected future climates (2070 year), from which possible permanent refugia for P. koraiensis were identified. Results: Using the random forest supervised learning algorithm, we developed models of the modern distribution of P. koraiensis in accordance with the five selected bioclimatic variables (Kira's warmth and coldness indices, the index of continentality, the rain precipitation index, and the snow precipitation index). In addition to current climatic conditions, we performed this analysis for the climate of the Last Glacial Maximum and for the future projected climate (2070) under scenarios RCP2.6 and RCP8.5. Among the predictors, the rain index appears to be the most significant. The land area estimates with high suitability for P. koraiensis was 303,785 km(2) under current climatic conditions, 586,499 km(2) for the Last Glacial Maximum, and 337,573 km(2) for the future (2070) period under the RCP2.6 scenario, and 397,764 km(2) under the RCP8.5 scenario. Conclusions: Most of the potential range of P. koraiensis during the Last Glacial Maximum was located outside the current distribution area of the species. The climatically suitable P. koraiensis habitats will likely disappear in the western part of its modern range. In the southern part of the range, which includes glacial refugia, the areas of continuous distribution of the P. koraiensis populations since the end of the Pleistocene are expected to be fragmented, but some localities in the north of the Korean Peninsula, northeast China, southern Primorye (Russia), and central Honshu (Japan) with suitable climatic conditions for the species will support the existence of populations.

We assess the impact of typhoon Maysak (2020) on the canopy structure of mixed coniferous-broadleaved forests with Abies holophylla, Pinus koraiensis and a complex of deciduous broad-leaved species and secondary oak forests of Quercus mongolica. The study was conducted in the experimental forest of the Botanical Garden-Institute FEB RAS. We classified the natural forest vegetation of the study area, created a high-resolution vegetation map, and assessed the damage from typhoon Maysak remotely using the ultra-high resolution images, obtained with an unmanned aerial vehicle. We found that the largest number and area of canopy gaps are associated with the conditionally primary coniferous-broadleaved forests, where Abies holophylla and Pinus koraiensis form the main canopy layer. The smallest number and area of gaps relate to the secondary oak forests.

An annotated checklist of 250 vascular plants species in the local flora of the upper reaches of Yarap River (southern macroslope of the Badzhal Range) is given. For the first time, Aconitum subvillosum, Arctous erythrocarpa, Carex ussuriensis, Macrohystrix komarovii, Neottianthe cucullata, Poa arsenjevii, Salix rhamnifolia are recorded for the flora of the Badzhal Range; a total 20 species, three of which, Chrysosplenium krestovii, Silene badzhalensis and Calamagrostis burejensis, were previously described as new to science. In addition, rare and endemic Red Data Book species were found, there are: Aconitum baburinii, Aster woroschilovii, Calypso bulbosa, Cardamine tomentella, Epipogium aphyllum, Leontopodium blagoveshczenskyi, Neottianthe cucullata, Rhodiola rosea, Saussurea tomentosa, Phlomoides woroschilovii, Pentactina schlothauerae, Taraxacum badzhalense, Viola brachyceras, Weigela suavis. The vegetation of the study area is briefly characterized.

Betula ovalifolia Rupr. (Betulaceae) is a dwarf birch broadly distributed in northeast Asia, but in Japan limited to two mires in Hokkaido where it is endangered because of drying habitats due to open ditches. Moreover, putative hybrids between B. ovalifolia and a congener grow along the ditches, suggesting the risk of genetic pollution and extirpation of B. ovalifolia. We aimed to elucidate the parental species of the hybrids, to develop species-specific PCR primers to cost-effectively identify hybrids without DNA sequencing, and to examine using the primers whether hybrids invade the mires. Sequencing of nrDNA ITS revealed that the parental species were B. ovalifolia and the allopatric B. ermanii, not B. platyphylla, which inhabited the same ditches. The developed primers successfully amplified the DNA of the parental species and the hybrids with a low enough error rate to screen the hybrids. PCR using the primers indicated that six of eight putative individuals were hybrids while the other two were atypically tall individuals of B. ovalifolia. Exfoliating twig bark was a diagnostic characteristic of the hybrids. Tests for hybrids using the primers showed no evidence of hybrids inside the mires. The hybrids have the same parents as the endangered Hokkaido endemic, B. apoiensis, but the hybrids in the ditches are the consequence of human disturbance and are thus considered to have no conservation value.

Abstract Accurate remote detection of various forest disturbances is a challenge in global environmental monitoring. Addressing this issue is crucial for forest health assessment, planning salvage logging operations, modeling stand dynamics, and estimating forest carbon stocks and uptake. Substantial progress on this problem has been achieved owing to the rapid development of remote sensing devices that provide very high‐resolution images. Concurrently, image processing algorithms have witnessed rapid development owing to the extensive use of artificial neural networks with complex architectures and deep learning approaches. This opens new opportunities and perspectives for applying deep learning methods to solving various problems in environmental sciences. In this study, we used deep convolutional neural networks (DCNNs) to recognize forest damage induced by windthrows and bark beetles. We used satellite imagery of very high resolution in visual spectra represented as pansharpened images (RGB channels). When predicting forest damage, we obtained accuracies higher than 90% on test data for recognition of both windthrow areas and damaged trees impacted by bark beetles. A comparative analysis indicated that the DCNN‐based approach outperforms traditional pixel‐based classification methods (AdaBoost, random forest, support vector machine, quadratic discrimination) by at least several percentage points. DCNNs can learn a specific pattern of the area of interest and thus yield fewer false positive decisions than pixel‐based algorithms. The ability of DCNNs to generalize makes them a good tool for delineating smooth and ill‐defined boundaries of damaged forest areas, such as windthrow patches.

We describe the new association Lycopo lucidi–Alnetum japonicae Korznikov, Verkholat & Krestov 2021 ass. nov. of the Alnus japonica swampy forests of the coastal plains and river valleys in the south of the Primorye Territory of Russia. The association includes two subassociations: Lycopo lucidi–Alnetum japonicae typicum Korznikov, Verkholat & Krestov 2021 subass. nov. and the preliminary delineated Lycopo lucidi–Alnetum japonicae betuletosum davuricae subass. prov. developing on gently sloping foothills with a lateral inflow of moisture and is transitional to zonal broad-leaved forests of the class Quercetea mongolicae Song ex Krestov et al. 2006. The association is classified to the alliance Fraxino–Alnion japonicae Miyawaki et al. 1977 described from Japan and belonging to the order Alnetalia japonicae Miyawaki et al. 1977 and the class Alnetea japonicae Miyawaki et al. 1977. We also validate the name of the association Stellario longifoliae–Alnetum japonicae Ohno in Miyawaki 1988 nom. inval. (art. 5) from Hokkaido Island, Northern Japan.

Island disharmony refers to the biased representation of higher taxa on islands compared to their mainland source regions and represents a central concept in island biology. Here, we develop a generalizable framework for approximating these source regions and conduct the first global assessment of island disharmony and its underlying drivers. We compiled vascular plant species lists for 178 oceanic islands and 735 mainland regions. Using mainland data only, we modelled species turnover as a function of environmental and geographic distance and predicted the proportion of shared species between each island and mainland region. We then quantified the over- or under-representation of families on individual islands (representational disharmony) by contrasting the observed number of species against a null model of random colonization from the mainland source pool, and analysed the effects of six family-level functional traits on the resulting measure. Furthermore, we aggregated the values of representational disharmony per island to characterize overall taxonomic bias of a given flora (compositional disharmony), and analysed this second measure as a function of four island biogeographical variables. Our results indicate considerable variation in representational disharmony both within and among plant families. Examples of generally over-represented families include Urticaceae, Convolvulaceae and almost all pteridophyte families. Other families such as Asteraceae and Orchidaceae were generally under-represented, with local peaks of over-representation in known radiation hotspots. Abiotic pollination and a lack of dispersal specialization were most strongly associated with an insular over-representation of families, whereas other family-level traits showed minor effects. With respect to compositional disharmony, large, high-elevation islands tended to have the most disharmonic floras. Our results provide important insights into the taxon- and island-specific drivers of disharmony. The proposed framework allows overcoming the limitations of previous approaches and provides a quantitative basis for incorporating functional and phylogenetic approaches into future studies of island disharmony.

Regional species assemblages have been shaped by colonization, speciation and extinction over millions of years. Humans have altered biogeography by introducing species to new ranges. However, an analysis of how strongly naturalized plant species (i.e. alien plants that have established self-sustaining populations) affect the taxonomic and phylogenetic uniqueness of regional floras globally is still missing. Here, we present such an analysis with data from native and naturalized alien floras in 658 regions around the world. We find strong taxonomic and phylogenetic floristic homogenization overall, and that the natural decline in floristic similarity with increasing geographic distance is weakened by naturalized species. Floristic homogenization increases with climatic similarity, which emphasizes the importance of climate matching in plant naturalization. Moreover, floristic homogenization is greater between regions with current or past administrative relationships, indicating that being part of the same country as well as historical colonial ties facilitate floristic exchange, most likely due to more intensive trade and transport between such regions. Our findings show that naturalization of alien plants threatens taxonomic and phylogenetic uniqueness of regional floras globally. Unless more effective biosecurity measures are implemented, it is likely that with ongoing globalization, even the most distant regions will lose their floristic uniqueness.

Very high resolution satellite imageries provide an excellent foundation for precise mapping of plant communities and even single plants. We aim to perform individual tree recognition on the basis of very high resolution RGB (red, green, blue) satellite images using deep learning approaches for northern temperate mixed forests in the Primorsky Region of the Russian Far East. We used a pansharpened satellite RGB image by GeoEye-1 with a spatial resolution of 0.46 m/pixel, obtained in late April 2019. We parametrized the standard U-Net convolutional neural network (CNN) and trained it in manually delineated satellite images to solve the satellite image segmentation problem. For comparison purposes, we also applied standard pixel-based classification algorithms, such as random forest, k-nearest neighbor classifier, naive Bayes classifier, and quadratic discrimination. Pattern-specific features based on grey level co-occurrence matrices (GLCM) were computed to improve the recognition ability of standard machine learning methods. The U-Net-like CNN allowed us to obtain precise recognition of Mongolian poplar (Populus suaveolens Fisch. ex Loudon s.l.) and evergreen coniferous trees (Abies holophylla Maxim., Pinus koraiensis Siebold & Zucc.). We were able to distinguish species belonging to either poplar or coniferous groups but were unable to separate species within the same group (i.e. A. holophylla and P. koraiensis were not distinguishable). The accuracy of recognition was estimated by several metrics and exceeded values obtained for standard machine learning approaches. In contrast to pixel-based recognition algorithms, the U-Net-like CNN does not lead to an increase in false-positive decisions when facing green-colored objects that are similar to trees. By means of U-Net-like CNN, we obtained a mean accuracy score of up to 0.96 in our computational experiments. The U-Net-like CNN recognizes tree crowns not as a set of pixels with known RGB intensities but as spatial objects with a specific geometry and pattern. This CNN’s specific feature excludes misclassifications related to objects of similar colors as objects of interest. We highlight that utilization of satellite images obtained within the suitable phenological season is of high importance for successful tree recognition. The suitability of the phenological season is conceptualized as a group of conditions providing highlighting objects of interest over other components of vegetation cover. In our case, the use of satellite images captured in mid-spring allowed us to recognize evergreen fir and pine trees as the first class of objects (“conifers”) and poplars as the second class, which were in a leafless state among other deciduous tree species.

Aim Understanding how natural forest disturbances control tree regeneration is key to predicting the consequences of globally accelerating forest diebacks on carbon stocks and forest biodiversity. Tropical cyclones (TCs) are important drivers of forest dynamics in Eastern Asia, and it is predicted that their importance will increase. However, little is known about the impact of TCs on forest regeneration. Location Latitudinal gradient from south Korea (33 degrees N) to the Russian Far East (45 degrees N). Time period Last 300 years. Major taxa studied Quercus mongolica, Abies nephrolepis and Pinus koraiensis. Methods We explored the effects of TC activity on canopy accession strategies derived from long-term tree radial growth patterns along a 1,500-km latitudinal gradient of decreasing TC activity. We analysed canopy accession strategies for > 800 trees of three widely distributed tree species by dividing them into gap trees (GTs), which established immediately after gap formation, and released trees (RTs), which accessed the upper canopy after a period of competitive suppression. Results We found a substantial decrease in GTs and increase in RTs proportionally along the gradient of decreasing TC activity. Pinus koraiensis and A. nephrolepis exhibited high variability in the proportions of the individual canopy accession strategies along the latitudinal gradient, whereas it was more stable for Q. mongolica. We identified the gradient of TC activity as the main driver influencing canopy dynamics and thus changes in life-history traits for P. koraiensis and Q. mongolica, whereas maximal growth rate was the main driver for A. nephrolepis. Main conclusions Flexibility in growth strategies enabled the studied species to cover extensive areas and indicates that they will be able to cope with shifts in disturbance regimes induced by the poleward migration of TCs and increasing TC intensity. Our results highlight the canopy accession strategy as an ecological indicator of past disturbance activity.