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Dryland wetland vegetation is, paradoxically, both highly sensitive and extremely resilient to environmental change. In the short-term, rapid responses of wetland biota and ecological processes to wetting and drying, which influence ecosystem structure and function, enable rapid reproduction which enhances long-term resilience. However, over longer periods, mechanisms such as seed dormancy and persistent seed and egg banks enable dryland wetland ecosystems to recover after major environmental perturbations such as mega-droughts or wildfire. Climate change is likely to have a significant effect on key drivers of ecological response in dryland wetlands, including hydrology and its interface with other climatic stimuli, e.g. temperature, as well as the frequency and intensity of extreme events. Like species, wetland ecosystems may respond to climate change in three main ways, namely, disappear, persist without significant adjustment, or transform. Here, we consider the conditions under which each of these responses may eventuate for dryland wetlands, by using wetland vegetation of the northern Murray–Darling Basin Australia, as a case study. We also explore what wetland transformation might entail in this region in terms of wetland ecological character and the key values this supports. Finally, we consider the implications for wetland policy and management at present and as trajectories of wetland change unfold. Dryland wetland vegetation is both highly sensitive and remarkably resilient to environmental change. In the short term, this includes rapid responses to wetting and drying. Over extended periods, these ecosystems recover impressively from major environmental disturbances such as mega-droughts or wildfire. As the effects of climate change intensify, the resilience of dryland wetlands will be challenged, leading to scenarios of persistence, transformation or disappearance. With a focus on Australia's northern Murray–Darling Basin, we explore the wetland policy and management implications. This article belongs to the collection Environmental Flows in Northern Murray–Darling Basin: what we know about the science and management after a decade of practice. [ABSTRACT FROM AUTHOR]

The rapid drop in groundwater level and the degradation of groundwater-dependent ecosystems (GDEs) has led to serious imbalances in the development of the socio-ecological system (SES) in Minqin Oasis, northwest China. In this study, the interactions between the elements of the SES were analyzed, and the effects of the implementation of nature-based solutions (NbS) and the resilience of the SES were assessed using the methods of linear trend analysis, correlation, and fuzzy comprehensive evaluation. The results showed that: (i) the most important contributing factor to the increase in groundwater depth (GLD) and the degradation of GDEs was the continuous groundwater extraction for the irrigation of farmland; and (ii) the natural vegetation began to be degraded when the GLD surpassed 5 m; (iii) the initial goal of NbS was achieved, the increase in GLD has been curbed, and the vegetation and the wetland area of Qingtu lake have begun to be restored. The SES resilience index increased by a factor of 1.82 from 2009 to 2017; however, it was still below 0.6, and thus the NbS should be continued in the future. This study provides a reference for the sustainable development of the SES in other similar areas under various environmental challenges. [ABSTRACT FROM AUTHOR]

Copyright of Pearl River is the property of Pearl River Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ellenberg indicator values (EIV) are widely used in vegetation ecology, but the values for many species in Southeastern Europe are not available due to incomplete knowledge of their ecology: it is therefore of paramount importance to estimate missing values in existing databases. The entire EIV set for a single species can be missing or a single EIV can be missing for species for which other indicator values are available. Our aim here is to provide a simple method to impute missing values for species who have missing data in a single or multiple EIV. For this purpose, we adopt a multiple imputation procedure and compare a number of imputation methods on the basis of two datasets: i) “indices”, the set of 9 Ellenberg indicators taken from literature, available for 10,824 species and ii) “vegetation”, a set describing the physical and climatic characteristics (Light, Temperature, Continentality, Soil moisture, Nitrogen, Soil pH, Hemeroby index, Humidity, Organic_matter) of 29,935 relevés from Southeastern Europe where at least one tree species is present. The imputation methods we considered are: k-Nearest Neighbour, multiple linear regression (with or without collinearity correction), Reprediction Algorithm, Weighted Averaging (WA) and Weighted Averaging Partial Least Squares (WAPLS) regression. The different methods of imputation were compared by looking at the output produced and its deviation from the “true” observed values for a set of species with known EIVs. We have considered a set of species with known EIVs and proceeded to multiple imputation using the methods above; as a measure of performance we adopted the mean squared error (MSE) estimate, and expert judgement of ecological consistency. Models based on Regression and k-Nearest Neighbour seem to outperform the others. On the contrary, Reprediction algorithm in its different forms: produced less satisfactory results.Imputation of missing values is generally based on expert knowledge or on some variant of weighted averaging (also known as Hill’s method). Here we show that other methods may be more effective and should be appropriately considered by vegetation scientists, since those may allow the application of EIVs in other biogeographic regions.

Abstract A key aspect of nature conservation is knowledge of which aspects of nature to conserve or restore to favor the characteristic diversity of plants in a given area. Here, we used a large plant dataset with >40 000 plots combined with airborne laser scanning (lidar) data to reveal the local characteristics of habitats having a high plant dark diversity—that is, absence of suitable species—at national extent (>43 000 km2). Such habitats have potential for reaching high realized diversity levels and hence are important in a conservation context. We calculated 10 different lidar based metrics (both terrain and vegetation structure) and combined these with seven different field‐based measures (soil chemistry and species indicators). We then used Integrated Nested Laplace Approximation for modelling plant dark diversity across 33 North European habitat types (open landscapes and forests) selected by the European communities to be important. In open habitat types high‐dark‐diversity habitats had relatively low pH, high nitrogen content, tall homogenous vegetation, and overall relatively homogenous terrains (high terrain openness) although with a rather high degree of local microtopographical variations. High‐dark‐diversity habitats in forests had relatively tall vegetation, few natural‐forest indicators, low potential solar radiation input and a low cover of small woody plants. Our results highlight important vegetation, terrain‐ and soil‐related factors that managers and policymakers should be aware of in conservation and restoration projects to ensure a natural plant diversity, for example low nutrient loads, natural microtopography and possibly also open forests with old‐growth elements such as dead wood and rot attacks.

A key aspect of nature conservation is knowledge of which aspects of nature to conserve or restore to favor the characteristic diversity of plants in a given area. Here, we used a large plant dataset with >40 000 plots combined with airborne laser scanning (lidar) data to reveal the local characteristics of habitats having a high plant dark diversity—that is, absence of suitable species—at national extent (>43 000 km2). Such habitats have potential for reaching high realized diversity levels and hence are important in a conservation context. We calculated 10 different lidar based metrics (both terrain and vegetation structure) and combined these with seven different field‐based measures (soil chemistry and species indicators). We then used Integrated Nested Laplace Approximation for modelling plant dark diversity across 33 North European habitat types (open landscapes and forests) selected by the European communities to be important. In open habitat types high‐dark‐diversity habitats had relatively low pH, high nitrogen content, tall homogenous vegetation, and overall relatively homogenous terrains (high terrain openness) although with a rather high degree of local microtopographical variations. High‐dark‐diversity habitats in forests had relatively tall vegetation, few natural‐forest indicators, low potential solar radiation input and a low cover of small woody plants. Our results highlight important vegetation, terrain‐ and soil‐related factors that managers and policymakers should be aware of in conservation and restoration projects to ensure a natural plant diversity, for example low nutrient loads, natural microtopography and possibly also open forests with old‐growth elements such as dead wood and rot attacks. [ABSTRACT FROM AUTHOR]

The rapid drop in groundwater level and the degradation of groundwater-dependent ecosystems (GDEs) has led to serious imbalances in the development of the socio-ecological system (SES) in Minqin Oasis, northwest China. In this study, the interactions between the elements of the SES were analyzed, and the effects of the implementation of nature-based solutions (NbS) and the resilience of the SES were assessed using the methods of linear trend analysis, correlation, and fuzzy comprehensive evaluation. The results showed that: (i) the most important contributing factor to the increase in groundwater depth (GLD) and the degradation of GDEs was the continuous groundwater extraction for the irrigation of farmland; and (ii) the natural vegetation began to be degraded when the GLD surpassed 5 m; (iii) the initial goal of NbS was achieved, the increase in GLD has been curbed, and the vegetation and the wetland area of Qingtu lake have begun to be restored. The SES resilience index increased by a factor of 1.82 from 2009 to 2017; however, it was still below 0.6, and thus the NbS should be continued in the future. This study provides a reference for the sustainable development of the SES in other similar areas under various environmental challenges.

Forbs are a culturally and ecologically important yet poorly studied component of the Pacific Northwest Bunchgrass (PNB) ecosystem of western North America. Because many PNB forbs emerge early in the spring and senesce at the onset of summer, typical vegetation surveys, which occur mid‐summer, likely underrepresent forbs. We evaluated how the timing of vegetation sampling affected estimates of perennial forb abundance, richness, and floral density, with a focus on species that are culturally significant to Indigenous people of the region. We sampled 29 plots three times: mid‐summer (July), as well as 7 (May) and 12 (April) weeks prior. Timing had large effects on estimates, with significant declines in forb richness (42%), cover (80%), and floral density (95%) between April and July. The density of Camassia quamash and Lomatium cous, two culturally important species, declined 91% and 96%, respectively, from April to July. Nearly 65% of forbs had documented uses by Plateau Tribes. The consequences of biased estimates are significant and (1) limit our understanding of fundamental ecological processes and interactions; (2) hinder effective conservation and management because we lack information on forb abundance, status, and trends, and (3) result in disproportionately negative impacts to Indigenous communities as many forbs are important for subsistence and ceremonial purposes. Vegetation sampling during the spring months coincident with peak forb abundance, in addition to summer sampling would provide more appropriate data with which to evaluate and characterize PNB vegetation dynamics and improve our understanding, management, and conservation of native forbs. [ABSTRACT FROM AUTHOR]

Karst Tiankengs are one type of negative topography that are of high value for conservation, providing habitats and breeding unique biological resources not found in the surrounding landscape. In recent years, the studies on karst Tiankeng in China has increased our understanding of diverse geological and ecological questions, from the formation and evolution of Tiankeng to species diversity. Based on a systematic review of the previous studies on karst Tiankeng, we reviewed the main advances and new findings, and addressed key topics for future studies. These key findings and topics include the distribution, evolution and vegetation ecology of Tiankeng. We also propose five key areas of focus for future studies:(1)The causes of Tiankeng formation and its vegetation ecology in systematicness, large scale and multidisciplinary collaboration;(2)The effect of biological resources in Tiankeng on ecological restoration of desertification area outside Tiankeng;(3)The distribution of soil microbial community and their interactions with plants in Tiankeng;(4)The impact of environmental change on karst Tiankeng ecosystem;(5)The assessment of the impact of tourism development on Tiankeng vegetation ecology. [ABSTRACT FROM AUTHOR]

• Estimating missing Ellenberg Indicator Values (EIV) could help plant ecology studies. • We tested and compared several methods for estimating missing EIV from existing data. • Multiple Linear Regression and k-Nearest Neighbour performed better than the others. • Statistical methods are more effective than imputation based on expert knowledge. • This approach would greatly facilitate monitoring species with unknown EIV. Ellenberg indicator values (EIV) are widely used in vegetation ecology, but the values for many species in Southeastern Europe are not available due to incomplete knowledge of their ecology: it is therefore of paramount importance to estimate missing values in existing databases. The entire EIV set for a single species can be missing or a single EIV can be missing for species for which other indicator values are available. Our aim here is to provide a simple method to impute missing values for species who have missing data in a single or multiple EIV. For this purpose, we adopt a multiple imputation procedure and compare a number of imputation methods on the basis of two datasets: i) "indices", the set of 9 Ellenberg indicators taken from literature, available for 10,824 species and ii) "vegetation", a set describing the physical and climatic characteristics (Light, Temperature, Continentality, Soil moisture, Nitrogen, Soil pH, Hemeroby index, Humidity, Organic_matter) of 29,935 relevés from Southeastern Europe where at least one tree species is present. The imputation methods we considered are: k-Nearest Neighbour, multiple linear regression (with or without collinearity correction), Reprediction Algorithm, Weighted Averaging (WA) and Weighted Averaging Partial Least Squares (WAPLS) regression. The different methods of imputation were compared by looking at the output produced and its deviation from the "true" observed values for a set of species with known EIVs. We have considered a set of species with known EIVs and proceeded to multiple imputation using the methods above; as a measure of performance we adopted the mean squared error (MSE) estimate, and expert judgement of ecological consistency. Models based on Regression and k-Nearest Neighbour seem to outperform the others. On the contrary, Reprediction algorithm in its different forms: produced less satisfactory results. Imputation of missing values is generally based on expert knowledge or on some variant of weighted averaging (also known as Hill's method). Here we show that other methods may be more effective and should be appropriately considered by vegetation scientists, since those may allow the application of EIVs in other biogeographic regions. [ABSTRACT FROM AUTHOR]

SWEA-Dataveg is a vegetation-plot database collecting observations mainly in sub-Saharan Africa but also open to the rest of the African continent. To date this database contains more than 5,500 plot observations provided by 47 sources (projects, monographs, and articles). While the database is stored in PostgreSQL (including the PostGIS extension), the R-package "vegtable" implements a suitable exchange format. In this article we assess the current content of SWEA-Database and introduce its history and future as a repository of data for syntaxonomic assessments and macroecological research. [ABSTRACT FROM AUTHOR]

CalJep is a spatially enabled database that reconciles or cross-walks the two prominent electronic plant distribution lists for California: CalFlora and Jepson. We intersected the distribution information from the two data sources to create a refined spatial distribution repository that can be used to examine patterns of plant diversity, distribution ranges of individual plant species or infrataxa, or vegetation associations. These data will allow scientists and resource managers to examine potential range maps for non-native plants, create range maps for plant species of restoration interest, and corroborate lines of evidence for determining appropriate management and conservation activities. We present here a detailed description of the methods used to create the CalJep geodatabase, data rendered from its creation, and a discussion of its applicability to a wide range of biogeographical and ecological questions, including restoration planning and adaptive management for the Bay-Delta ecosystem. CalJep records 7,887 plant species, subspecies, and varieties mapped onto 228 ecological subunits with corresponding distributional information for vascular plant species at varying levels of confidence. Information derived from this geodatabase is inherently as accurate as the digital floras used to create it; hence, its utility is best realized when implemented at the regional or statewide scale. CalJep provides a previously unavailable service to vegetation science in California and to resource managers operating within the Bay-Delta ecosystem.

Questions: Substantial variation between observers has been found when comparing parallel land-cover maps, but how can we know which map is better? What magnitude of error and inter-observer variation is expected when assigning land-cover types and is this affected by the hierarchical level of the type system, observer characteristics, and ecosystem properties? Study area: Hvaler, south-east Norway. Methods: Eleven observers assigned mapping units to 120 stratified random points. At each observation point, the observers first assigned a mapping unit to the point independently. The group then decided on a 'true' reference mapping unit for that point. The reference was used to estimate total error. 'Ecological distance' to the reference was calculated to grade the errors. Results: Individual observers frequently assigned different mapping units to the same point. Deviating assignments were often ecologically close to the reference. Total error, as percentage of assignments that deviated from the reference, was 35.0% and 16.4% for low and high hierarchical levels of the land-covertype system, respectively. The corresponding figures for inter-observer variation were 42.8% and 19.4%, respectively. Observer bias was found. Particularly high error rates were found for land-cover types characterised by human disturbance. Conclusions: Access to a 'true' mapping unit for each observation point enabled estimation of error in addition to the inter-observer variation typically estimated by the standard pairwise comparisons method for maps and observers. Three major sources of error in the assignment of land-cover types were observed: dependence on system complexity represented by the hierarchical level of the land-cover-type system, dependence on the experience and personal characteristics of the observers, and dependence on properties of the mapped ecosystem. The results support the necessity of focusing on quality in land-cover mapping, among commissioners, practitioners and other end users. [ABSTRACT FROM AUTHOR]

It has been generally accepted that Scots pine (Pinus sylvestris L.) became extinct in Ireland c. AD 400. The species was reintroduced in the mid-17th century and has been widely planted. It has been included in the Native Woodland Scheme, which provides grants to establish or restore native woodlands. However, its native status in Ireland has been disputed and the vegetation ecology and conservation value of Irish pinewoods have been poorly understood. These knowledge gaps have been addressed using an approach combining vegetation ecology and palaeoecology. Vegetation surveys were conducted at eighteen pinewoods in Ireland and six in Scotland. Cluster analysis was used to evaluate the floristic similarity between plots and classify them into groups. One of the Irish pinewoods was of unknown origin (Rockforest, Co. Clare). To reconstruct its vegetation history, a sediment core was extracted from Rockforest Lough. Pollen, macrofossil and dating analyses were conducted. Cluster analysis identified four groups, representing distinct pinewood vegetation types. The vegetation of certain Irish groups and sites exhibited similarities with that of extant native pinewoods elsewhere in oceanic north-west Europe or fossil assemblages from ancient Irish pinewoods. While the vegetation of Irish pinewoods did not correspond to that of typical Scottish Caledonian forests, Coronation Plantation and the bog pinewoods at Clonfinane and All Saints Bog exhibited strong similarities with other native Scottish pinewoods of high conservation value. Natural regeneration of P. sylvestris was poor overall. The pollen diagram from Rockforest Lough showed a continuously high Pinus pollen frequency (38-51% of total terrestrial pollen) from c. AD 350 to the present. Macrofossil evidence demonstrated local presence of P. sylvestris around Rockforest Lough c. AD 840. The available historical sources indicated a long history of woodland cover at Rockforest. A separate analysis of a peat core from nearby Aughrim Swamp also showed a continuous Pinus signal from c. AD 350 to the present. The findings of the vegetation analysis suggest that P. sylvestris woodlands are an important resource for Irish biodiversity, particularly given the country's low native woodland cover. The palaeoecological data indicate that native P. sylvestris persisted at Rockforest from c. AD 350 to the present. The hypothesis that P. sylvestris became extinct in Ireland is rejected. These findings should inform evidence-based forest management and policy. They support the inclusion of P. sylvestris in the Native Woodland Scheme. In general, reintroduced P. sylvestris should be managed as a native species in Irish woodlands. The data presented should inform site and species selection. The P. sylvestris population at Rockforest is of high conservation value but its rarity increases its extinction risk. It should be carefully managed and monitored and seed-sourcing must be compatible with the long-term viability of the population. Cooperation between forestry and nature conservation agencies is needed to ensure its continued survival and to develop opportunities for the restoration of native pinewoods in Ireland. [ABSTRACT FROM AUTHOR]

Copyright of Contributii Botanice is the property of Contributii Botanice and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of vegetation and microtopography on fine-scale variability of thaw depth is largely unknown but potentially important for improving modeling of ecosystem-permafrost interactions. To elucidate their influence, we measured tree density, shrub cover and cryptogam presence (lichen and bryophyte) on forested permafrost peat plateaus in the discontinuous permafrost zone in the southern Northwest Territories, Canada. Greater tree density was associated with shallower thaw depth (approximately one quarter of the variance), whereas shrub cover had a negligible influence on thaw depth. Cryptogam species influenced thaw depth, with greater thaw depth associated with Sphagnum than with Cladonia (a difference on the order of 10%). Greater thaw depth occurred beneath hummocks than beneath hollows (a difference also on the order of 10%). Together, canopy cover, cryptogam species and microforms contribute to a variation of roughly half the variance in thaw depth in the peat plateau landscape. [ABSTRACT FROM AUTHOR]

Dark diversity is a promising concept for prioritising management efforts as it focuses on species that are present in the regional pool, but locally absent even though environmental requirements are met. Currently, we lack knowledge of what characterises species belonging to the dark diversity more often than others, although this is important knowledge for restoration and conservation actions., We applied the concept to a massive national (Danish) plant diversity data base, containing 236 923 records from 15 160 surveys involving 564 species. This enabled the first geographically comprehensive (43 000 km2) assessment of dark diversity, at a spatial resolution relevant for conservation and restoration planning (78 m2) across multiple terrestrial habitats, thereby maximising the practical applications of this concept. The probability for a given plant species to belong to the dark diversity was computed and logistically regressed against variables representing its ecological preferences (e.g. nutrient availability), strategies (competitor, stress tolerant, ruderal), mycorrhizal relationships, establishment capacities (seed mass) and dispersal abilities., Forty-six percent of the species had a high probability (>95%) of being part of dark diversity, whereas for 7% of the species this probability was less than 60%., Typical dark diversity plant species tended to depend on mycorrhiza, were mostly adapted to low light and low nutrient levels, had poor dispersal abilities and were ruderals and stress intolerant., Synthesis and applications. Characterising species that are more often absent from suitable sites than others (dark diversity species) has important implications for the planning and management of natural ecosystems. From our study, practitioners gain insight into the factors triggering the absence of individual plant species in a seemingly suitable habitat. We highlight the need to carefully consider mycorrhizal inoculations with a suitable assemblage of fungi to promote the establishment success of dark diversity plants. Additionally, time-lags in plant species dispersal and establishment as well as spatial connectivity in fragmented habitats are central to consider in nature management although assisted migration might also aid poor dispersers. Finally, nutrient-poor localities are probably important 'islets' allowing nitrophobic dark diversity plant species to thrive within agricultural landscapes that are generally nutrient-rich. [ABSTRACT FROM AUTHOR]

The present work aims to describe the structure and floristic composition of the natural regeneration in a clearing of a Fragment of Mixed Ombrophilous Forest that underwent an intervention by burning after three years in the Municipality of Segredo, Rio Grande do Sul State, Brazil. We sampled 16 plots of 2 x 2 m, totaling 64 m². It was established that all plants with height greater than 0.3 m were included as criterion in the floristic survey. We found 240 plants belonging to 42 arboreal-shrub species. [ABSTRACT FROM AUTHOR]

The Slavonianmountains have an important place in the floristic and vegetation picture of the continental part of Croatia. For the most part, the forest cover of this region consists of common beech stands (Fagus sylvatica L.). Many authors have worked on defining plant communities of common beech in the northern part of Croatia in the last ten years. Even though this has greatly contributed to get a better understanding of them,many questions have remained open. This is so because the research wasmostly conducted on smaller geographical scale where local conditions (specific microhabitat, anthropogenic influences, etc.) significantly affected the phytosociological analyses. On the other hand, it is rather difficult to carry out the analyses on a larger geographical scale because many regions and/or vegetative types are still scarcely covered by relevés. The goal of this study is to analyze the floral composition of beech forests of Psunj, Papuk and Krndija mountains, which have not been sufficiently studied so far. The next goal is to define and draw boundaries between plant communities, and also to analyze some of the ecological and phytogeographical features. During field studies of beech forests of Psunj, Papuk and Krndija mountains, 88 relevés were made using central European Braun-Blanquet methodology. The relevés have been compared with the relevés of similar vegetation in the wider geographical region (N Croatia, N Slovenia, S Hungary). The analysis included 1509 published relevés of 13 associations from Slovene Phytosociological Database (Šilc 2006) and Croatian database of forests vegetation (Krstonošić et al. 2007) – Lamio orvale-Fagetum, Cardamine savensi-Fagetum, Isopyro-Fagetum, Vicio oroboidi-Fagetum, Hacquetio-Fagetum, Helleboro odori-Fagetum, Carici pilosae-Fagetum, Festuco drymeiae-Fagetum, Galio odorati-Fagetum, Polysticho setiferi-Fagetum, Luzulo-Fagetum, Castaneo-Fagetum i Blechno-Fagetum. The numerical analysis of the floral composition was made (cluster analysis, NMDS), as well as the analysis of ecological variables (DCA). To describe ecological conditions, Ellenberg’s indicator values were also used. Clasification was made by cluster analyses in PC-ORD (McCune&Mefford 1999). NMDS was made by R using Vegan (Oksanen et al. 2006) and DCAwas made by CANOCO 4.02 (Ter Braak and Šmilauer 2002). Slavonian hills are situated in the eastern part of Croatia, on the border of the Pannonian and Illyrian floristic area. The area is bordered by themountains of Papuk (953ma.s.l.) and Krndija in the north-west and north, and by the mountains of Psunj (989 m a.s.l.), Požeška gora (616 m a.s.l.) and Dilj (471m a.s.l.) in the south-east and east. The average annual air temperature in the researched area is around 11 °C, and it increases from the west to the east. January is the coldest month of the year, and July is the wormest. The average annual amount of precipitation decreases from the west to the east. The geological structure is quite diverse. Most of the mountain range is made of silicate and sandstone rock, while parts of Papuk and Požeška gora, and most parts of Dilj are made of limestone and marlstone. We have established three associations of beech forests that can be divided into acidophilic beech forests (Luzulo-Fagetum), submountainous beech forests (Festuco drymeiae-Fagetum luzuletosum and caricetosum pilosae) and mountainous beech forests (Cardamino savensi-Fagetum), (Fig. 2, 3, Tab. 1). Ass. Luzulo luzuloidi-Fagetum This association has already been reported in the study area. These stands are established on acid substrates on steep slopes (Fig. 4, 5). They have very poor floral composition. Furthermore, typical stands are dominated by Luzula luzuloides and this mainly occurs on the northern slopes; there are also stands dominated by Vaccinium myrtillus, which occurs in slightly warmer habitats (cf. Tab. 1 and 2). Ass. Festuco drymeiae-Fagetum In the study region of Psunj, Papuk and Krndija mountains, two groups of relevés could be distinguished, even though there is no sharp distinction between them (Fig. 2). A more acidophilic group (subass. luzuletosum), where Festuca drymeia is dominant with a significant presence of Luzula luzuloides, comes in great complexes at higher altitudes and ismore present in the western and northern part of themountains. In the southern and eastern part, it can be found in small patches. The domination of the Carex pilosa is significant for the other group (subass. caricetosum pilosae). It can be found at lower altitudes and it ismore present in the eastern and southern part of themountains. In the floristic sense, it differs from subass. luzuletosum with a greater participation of species such as Carpinus betulus, Quercus petraea, Tilia tomentosa and others. In the area of the association, in the ditches and basins, there is a significant presence of species such as Polystichum setiferum, Dryopteris filix-mas, Acer pseudoplatanus, Sambucus nigra, etc. (Tab. 1, 2, Fig. 3, 4). Having analyzed the submountainous beech forests in the region of Psunj, Papuk and Krndija mountains, the question remains whether there are two associations, or different subassociations within the same association. To solve the status and relationship with the related associations, it is necessary to make a study that will include all submountainous beech forests in a wider geographical area. The description and systematic position of this association is a topic of much debate in phytosociological literature. We are of the opinion that none of the nomenclature combinations are satisfactory. Ass. Cardamino savensi-Fagetum Beech stands grow in the upper region of Mt. Papuk (over 700 m a.s.l.) and they can be clearly distinguished from all other studied stands by their floral composition. By comparing it with the relevés of beech forests fromliterature, it has been undeniably established that this was the case of mountainous beech forests of the suballiance Lamio orvalae-Fagetum. By its floral composition and ecological characteristics, these forests are most similar to those described under the name Cardamino savensi-Fagetum in Slovenia. Slavonian mountains are a region of well-indented relief, where various base soils, soil depths, expositions, etc., occur in a very small space. Consequently, forest plant communities appear in a delicate mosaic of different vegetation types, which often alternate and whose boundaries are usually not clear-cut. The composition of beech forest flora of Psunj, Papuk and Krndija, as well as the whole area of Slavonian mountains is characterized by a smaller number of species compared to beech forests of the Dinarian region and western Croatia. For the most part, some Illyrian species (Lamium orvala, Calamintha grandiflora, Cardamine trifolia, Rhamnus fallax and Euphorbia carniolica) are missing or come up very rarely, which has also been noted in some earlier studies. Sizeable regions of beech forests of Slavonian mountains are still quite inadequately explored from a phytosociological point of view. This is mainly the case with the westernmost and north-easternmost regions (Fig. 1). In order to solve the remaining open questions and to better define plant communities, it is necessary to study these regions as well.

The Major Megetation Types (MVT) and plant communities of the Soutpansberg Centre of Endemism are described in detail, with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 442 sample plots were ordinated using a DEtrended CORrespondence ANAlysis (DECORANA) and classified using TWo-Way INdicator SPecies ANalysis (TWINSPAN). The resulting classification was further refined with table-sorting procedures based on the Braun–Blanquet floristic–sociological approach of vegetation classification using MEGATAB. Eight MVT’s were identified and described as Eragrostis lehmanniana var. lehmanniana–Sclerocarya birrea subsp. caffra Blouberg Northern Plains Bushveld, Euclea divinorum–Acacia tortilis Blouberg Southern Plains Bushveld, Englerophytum magalismontanum–Combretum molle Blouberg Mountain Bushveld, Adansonia digitata–Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis–Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon–Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida–Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora–Rhus chirendensis Soutpansberg Forest Vegetation.

Long-term ecological studies are critical for providing key insights in ecology, environmental change, natural resource management and biodiversity conservation. However, island fire ecology is poorly understood. No previous studies are available that analyze vegetative changes in burned and unburned dry forest remnants on Wa'ahila Ridge, Hawai'i. This study investigates vegetation succession from 2008 to 2015, following a fire in 2007 which caused significant differences in species richness, plant density, and the frequency of woody, herb, grass, and lichens between burned and unburned sites. These findings infer that introduced plants have better competitive ability to occupy open canopy lands than native plants after fire. This study also illustrates the essential management need to prevent alien plant invasion, and to restore the native vegetation in lowland areas of the Hawaiian Islands by removing invasive species outplanting native plants after fire. [ABSTRACT FROM AUTHOR]

We present a paleoenvironmental reconstruction for the mountain fringe between the South-Eastern Alps and the Northern Dinarides (NE-Italy/W-Slovenia) during the Last Glacial Maximum. We focused on a new sedimentary and paleoecological archive spanning the LGM acme, located in an aggrading, permanently flooded and ponded plain, dammed by an active fluvioglacial megafan. The ecosystem reconstruction, based on two high resolution pollen records, is supported by a rich plant macrofossil flora and constrained by a robust radiocarbon chronology between 26 and 22 cal ka BP. We show evidence for persistence of boreal trees and of different open boreal forest types throughout the LGM at the south-eastern mountain fringe of the Alps and the Northern Dinarides. Fire frequency is responsible for high, oscillating forest openness. The paleobotanical record is discussed in the light of the ecogeographic diversity of the region. A belt formed by Swiss stone pine, larch and dwarf mountain pine on limestone bedrock, and accompanied by Spruce in the floodplain, extended uphill, while proximal outwash plain supported Scots pine and dwarf mountain pine. These differences arise from groundwater regimes rather than from local climate variability. A steep moisture gradient from the semiarid pedoclimatic regime prevailing in the Adriatic alluvial plain to the forested mountain fringe is related to the orographic rainout triggered by southern air circulation. Mesophytic broad-leaved forest trees did not withstand the LGM temperature extremes in zonal ecosystems at the Alpine–Dinaric fringe; however, the fossil evidence suggests a number of microrefugia in karstic and thermal spring habitats of the northern Adriatic. [ABSTRACT FROM AUTHOR]

Knowledge about relationships between specialization degree of species, i.e. the width of their realized niche and functional traits, may have important implications for the assessment of future population developments under environmental change. In this study, we used a recently introduced method to calculate ecological niche widths of plant species in mixed broad-leaved deciduous forests and to investigate the dependence between niche widths of plants and their functional traits and Ellenberg indicator values. The research is based on a dataset of 4556 phytosociological relevés of mixed broad-leaved deciduous forests in Slovenia. We calculated theta indices for 326 species, which ranks them along a continuous gradient of habitat specialization. For 272 species, we compiled 26 functional traits and Ellenberg indicator values. We found some significant correlations between theta indices of species and their functional traits and Ellenberg indicator values; habitat specialists thrive primarily on the highest altitudes, on colder, dry sites and achieve the age of first flowering later than generalists. They also have smaller seed diameter, lower leaf dry matter content, lower mean canopy height and bigger specific leaf area than generalists. Two species groups, chamaephytes and spring green species, are particularly characterized as specialist species. The added value of our work is in complementing the knowledge about the niche differentiating along different environmental gradients and species coexistence in mixed broad-leaved deciduous forests. [ABSTRACT FROM AUTHOR]

Questions The forest herb layer provides a multitude of ecosystem services as a result of its species-rich character. Herb layer diversity and biomass are both influenced by tree layer composition and species richness through species-specific influences on environmental conditions. The results of observational studies on richness-biomass relationships between tree and herb layer have not been unequivocal. We examined tree species identity and richness effects on herb layer species richness, composition, biomass and nutrient concentrations in young experimental tree plantations. Location BIOTREE tree diversity experiment, Kaltenborn, Germany. Methods Sixteen plots were planted in 2004, using a pool of four tree species (beech, oak, Douglas-fir, Norway spruce) and four richness levels, comprised of all possible species combinations. In this way, complete dilution was avoided, allowing separation of tree species identity and richness effects. Mixed plots consisted of a matrix of monospecific patches. One permanent vegetation quadrat of 1 m2 was established in the centre of four patches per plot. The herb layer was monitored in 2004 and 2010; in 2010 light measurements were performed in each quadrat, and in 2011 above-ground biomass was sampled on 0.25 m2 within the quadrat. Results Community composition shifted markedly between 2004 and 2010. Tree species identity did not yet influence temporal compositional turnover or herb layer species richness in 2004 and 2010. Ellenberg N indicated a temporal shift towards lower soil fertility under all tree species, whereas Ellenberg R indicated decreasing soil acidity under beech and Douglas-fir. Ellenberg L and F showed no shift from 2004 to 2010. Apart from the significantly lower Ellenberg N for beech, none of the Ellenberg indicators indicated interspecific differences. Douglas-fir, and especially Norway spruce, negatively influenced total above-ground herb layer biomass. Douglas-fir also induced lower relative light availability, higher potassium, magnesium and nitrogen concentrations and lower carbon:nitrogen ratios in the total biomass. Higher tree species richness positively affected graminoid and total biomass and also slightly increased plot-level herb layer species richness. Conclusions Despite the young age of the experiment, tree species identity and richness effects on the herb layer could be discerned. We expect these relations to become stronger with time. [ABSTRACT FROM AUTHOR]

Vegetation and soil sampling were undertaken in 47 relevés in two different sites in Beni Bousera (northern Morocco), 32 relevés were on ultramafic sites (peridotite) and 15 were on adjacent non-ultramafic soils (mica-schist). Soil composition of exchangeable elements (nickel, calcium, magnesium, calcium : magnesium ratio, iron, copper) and physicochemical characteristics (e.g. pH, cation exchange capacity, conductivity, carbonate) were investigated and the species composition and cover were recorded. Although there was a significant difference between the two types of soil shown by Student's t-test and principal component analysis, the 'serpentine factor' can be considered moderate on the basis of the observed heavy metal concentrations and of the related calcium : magnesium ratio. Correspondence and canonical analysis were used to detect the principal factors associated with gradients in species composition. This analysis showed a clear differentiation of vegetation among the plant communities. Preferential or strict serpentinophyte species were recognised, whereas no hyperaccumulator species have yet been found. The relation between vegetation and soil was investigated in a poorly studied ultramafic area in the north Morocco (Beni bousera). The peculiarities of this area are discussed in comparison with adjacent non ultramafic areas. This comparison shows a clear differentiation of vegetation among the plant communities. Preferential or strict serpentinophytes species were recognised but no hyperaccumulator species have yet been found. [ABSTRACT FROM AUTHOR]

Structure, composition and function are the three important attributes of forest ecosystems. These attributes change in response to climate, topography, soil and disturbances. The above mentioned factors along with forest succession are also responsible for both local and landscape level variations in forest ecosystems. The present study aimed to analyse the quantitative vegetation dynamics and diversity of plants from the dry deciduous forests and fallow lands of Doon Valley. Forest sites were chosen from three extreme end of the valley and other sites were selected according to the level of variations to study species richness, regeneration and change in community composition in the context of overstorey structure and invasion success of a non native invasive species Lantana camara employing nested quadrat method. Change in community composition has taken place with Shorea robusta as the main dominant and Mallotus philippensis, Syzygium cumini and Ehretia laevis becoming co - dominant tree species in all community; this association is new for these forests. Effect of overstorey structure was noticeable, highest species richness and diversity was increasing with a decrease in tree density and basal area. Lantana camara over past few years has become a threat to the western Himalayan forests. On the basis of IVI (Importance Value Index) assessment it is clear that Lantana is profusely growing in all types of habitats, on the other hand the invasion of other plant species is restricted to their suitable habitats. The invasion success of Lantana was found depending on forest gap size as gap size was significantly correlated to the inflorescence, infructescence and pollinator visitors. [ABSTRACT FROM AUTHOR]

We hypothesized that associations among plant functional traits may differ within different ecological assemblages and plant communities. Association among plant traits including plant maximum height, seed weight, fruit type, pollination mode, mean leaf area, and leaf type were explored within life forms, plant strategy groups along with lowland and montane forest vegetation. In total, 83 sampling plots of 400 m2 were placed along a 2400 m altitudinal gradient in Hyrcanian forest. Importance-values of species within vegetation types were used for weighting data and trait associations were explored using categorical principal component analysis. A G-test and Fisher's exact test of independence were used to retest significance of the correlations. Different paired trait associations (association lines) including height-leaf, height-seed, height-pollination, leaf-seed, seed-fruit and fruit-pollination were observed and their ecological or physiological basis was discussed. Life forms, strategy types and vegetation types differed based on association lines. Some of the well-known trade-offs appear by increasing scale from ecological groups to vegetation types in Hyrcanian forest. The observed patterns of trait associations in Hyrcanian forest and several other ecosystems of the world call the generality of previously accepted trait correlations into question. [ABSTRACT FROM AUTHOR]

The closed Tangra Yumco Basin underwent the strongest Quaternary lake-level changes so far recorded on the Tibetan Plateau. It was hitherto unknown what effect this had on local Holocene vegetation development. A 3.6-m sediment core from a recessional lake terrace at 4,700 m a.s.l., 160 m above the present lake level of Tangra Yumco, was studied to reconstruct Holocene flooding phases (sedimentology and ostracod analyses), vegetation dynamics and human influence (palynology, charcoal and coprophilous fungi analyses). Peat at the base of the profile proves lake level was below 4,700 m a.s.l. during the Pleistocene/Holocene transition. A deep-lake phase started after 11 cal ka BP, but the ostracod record indicates the level was not higher than ~4,720 m a.s.l. (180 m above present) and decreased gradually after the early Holocene maximum. Additional sediment ages from the basin suggest recession of Tangra Yumco from the coring site after 2.6 cal ka BP, with a shallow local lake persisting at the site until ~1 cal ka BP. The final peat formation indicates drier conditions thereafter. Persistence of Artemisia steppe during the Holocene lake high-stand resembles palynological records from west Tibet that indicate early Holocene aridity, in spite of high lake levels that may have resulted from meltwater input. Yet pollen assemblages indicate humidity closer to that of present potential forest areas near Lhasa, with 500-600 mm annual precipitation. Thus, the early mid-Holocene humidity was sufficient to sustain at least juniper forest, but Artemisia dominance persisted as a consequence of a combination of environmental disturbances such as (1) strong early Holocene climate fluctuations, (2) inundation of habitats suitable for forest, (3) extensive water surfaces that served as barriers to terrestrial diaspore transport from refuge areas, (4) strong erosion that denuded the non-flooded upper slopes and (5) increasing human influence since the late glacial. [ABSTRACT FROM AUTHOR]

The study presents the results of geobotanical investigations conducted in crop fields in the western Tian Shan Mts in Kyrgyzstan (Middle Asia). The main research focused on classification of weed communities developing within this poorly investigated area, were conducted in the vicinity of Bishkek and Kara-Balta in 2010. Altogether, 299 phytosociological relevés were sampled using the Braun-Blanquet method. Based on all segetal vegetation patches, the analyses distinguished a new association: Caucalido platycarpi-Vicietum michauxii. The results of these phytosociological studies fill a gap in the knowledge about the syntaxonomical diversity of the Middle Asia region, which is one of the most crucial for segetal weed species. The study shows that anthropogenic agrocoenoses could harbour relatively rich flora. Extensively cultivated fields could especially serve as a suitable habitat for many xerothermophilous and heliophilous plants. More than 75 species in vegetation plots, mainly permament weeds, have been found. There is also a considerable share of species coming over from swards, screes and meadows. [ABSTRACT FROM AUTHOR]