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In Yakutia, natural floodplain meadows and steppes have long been involved in economic activities. To develop methods of rational use, one needs to constantly consider the state of vegetation, mainly its constituent populations. Our research focuses on studying the dynamics of the vitality of the populations of the Agrostis diluta Kurcz. and steppe Psathyrostachys caespitosa (Sukaczev) Peschkova cereals. These species play an essential role in the composition of vegetation cover. We determined the vitality coefficient IVC. Our study of populations over several years has revealed the dynamic mobility of the vital structure, which is of adaptive significance and ensures the sustainability of populations. We have found that the vital structure of the cereal populations of the meadow Agrostis diluta and the steppe Psathyrostachys caespitosa during long-term studies (2007–2013 and 2007–2016, respectively) is heterogeneous. In unfavorable humidification conditions, we characterize years as depressive. Under favorable conditions of humidification, they quickly turn into thriving plants. In addition to the weather of the vegetation periods, habitat specificity affects the vitality of species populations that differ in ecological and coenotic characteristics. The Q quality index and IVC correspond to each other by year and form a clear descending order during the transition from a thriving to a depressive state. Currently, the vital state of the populations of both species is satisfactory.

The article presents the results of research conducted in Dengizkul and around this area. It identifies plant species in and around the lake and analyzes species composition. As a result of the analysis, 70 species of tall plants belonging to 24 families were identified in the lake. The identified species are divided into aquatic and riparian plants. Of these, 18 species are found in lake water and 52 species in its vicinity. The low number of high plant species in the lake water is due to the salinity of the water. The protection of this area is based on the natural conservation of the surrounding plant population.

The bud bank plays an important role in the regeneration of clonal plants after disturbance. However, specific effects of clipping disturbance on the bud bank and population characteristics of clonal plants remain unclear. Here, no-clipping (CK), low-intensity continuous clipping (LCC), and high-intensity single clipping (HSC) were tested on Triarrhena lutarioriparia, a typical rhizomatous clonal plant population. The results with respect to population characteristics and bud bank responses showed that: (1) Plant density under HSC and LCC was higher than that under CK, and compared with CK, bud density belowground decreased significantly under HSC; (2) The number of basal buds increased significantly under LCC but disappeared under HSC; the number of terminal buds under LCC and HSC decreased significantly; and (3) The proportions of guerrilla ramets under HSC and LCC were significantly lower than those under CK, while the proportions of phalanx ramets under HSC and LCC were significantly higher than those under CK. The bud bank is the main source of the aboveground population after clipping disturbance. Clipping changed bud-sprouting order and bud bank composition, ultimately leading the plant to change from guerrilla to phalanx growth form. This is an effective strategy for recovery from clipping disturbance.

Distinctive features of ex situ plant populations (outside natural habitats) are manifested during the formation and development of groups of individuals mainly in the process of their introduction and acclimatization. The experience and practice of using terms for ex situ plant populations has been analyzed. Information about artificially created plant groups is generalized. The results of the analysis concerning the definition of the term "ex situ plant population" and its use in relation to introduced plants are presented. The list of definitions for the following terms are given: "initial population", "introductive population", "introductive coenotic population", "introduced population", "cultivated populations", "agro population", "cultural population", "hybrid population", "artificial population", "experimental population", "spontaneous population". It has been stated that modeling, forming and copying methods are used to form ex situ plant populations. It has been noted that ex situ plant populations can be formed and developed independently or artificially formed. The scheme of distribution of ex situ plant populations by the degree of genetic integrity, ability to reproduce, duration of existence, size and stage of development, place and style of formation of the initial population is proposed. It has been established that groups of genetically homogeneous individuals of artificial plant groups that freely cross each other and for a long time reproduce offsprings can be characterized as populations. Such populations are the result of purposeful human activity on the introduction and cultivation of plants, and are largely dependent on anthropic influence. The study of their structure and dynamics is a prerequisite for predicting and evaluating the success of introductions and preventing threats of spontaneous propagation and uncontrolled, unwanted naturalization of plants under new growth conditions.

Population differentiation is a pervasive process in nature. At present, evolutionary studies on plant population differentiation address key questions by undertaking joint ecological and genetic approaches and employing a combination of molecular and experimental means. In this special issue, we gathered a collection of papers dealing with various ecological and genetic aspects of population differentiation in plants. In particular, this special issue encompasses eight research articles and two reviews covering a wide array of worldwide environments, plant functional types, genetic and genomic approaches, and common garden experiments to quantify molecular and/or quantitative trait differentiation in plant populations. Overall, this special issue stresses the validity of traditional evolutionary studies focused on plant populations, whilst emphasizing the integration of classical biological disciplines and state-of-the-art molecular techniques into a unique toolkit for evolutionary plant research., Several ecological and genetic processes acting in concert account for population differentiation, which is a pervasive process in nature that may eventually lead to speciation. In this special issue, we gathered a collection of papers dealing with various ecological and genetic aspects of population differentiation in plants covering a wide array of worldwide environments, plant functional types, genetic and genomic approaches, and common garden experiments to quantify molecular and/or quantitative trait differentiation in plant populations.

New York's Adirondack alpine zone harbors many rare vascular plants threatened by climate change, atmospheric deposition, and damage from recreational use. Here, we report on the results of population monitoring at 6-year intervals of 15 alpine areas. We sampled 366, 360, and 369 randomly placed plots in 2006–2007, 2013, and 2018–2019, respectively. Ten species were found in at least 5% of the plots, with Trichophorum cespitosum (Deer's Hair Club Sedge; 60% of plots) and Huperzia appressa (Mountain Firmoss; 42%) most frequent. Of these 10 species, 5 showed significant increases in density over time and 3 had no significant change in density. The 5 species showing increases also had densities positively correlated with metrics of current or former physical disturbance, such as exposure to western slopes and proximity to hiking trails. These data suggest many rare alpine plants are maintaining population levels; environmental heterogeneity and hiker education in the alpine zone may be contributing to this pattern.

Recovery of Mediterranean forests after field abandonment is a slow process, even without propagule limitations. This is mainly due to stressful conditions for seedling establishment. In this context, shrubs play a critical role in facilitating tree recruitment, but how this process unfolds after field abandonment is not entirely known. We evaluated the long-term dynamics of facilitation by the nurse shrub Retama sphaerocarpa in the recruitment of two ecologically contrasting oaks, the evergreen Quercus ilex and the deciduous Quercus faginea. Thirty years after field abandonment, we dated shrubs and oak established in an old field to estimate the annual recruitment rates and investigate temporal recruitment patterns. For oaks, we differentiated recruitment at each microsite (i.e., open or under shrub). To assess how nurse shrubs modulated environmental stressors, we modelled oak recruitment as a function of climatic variables. For the evergreen oak, we assessed these effects within each microsite. Finally, we estimated the annual interaction index between shrubs and oak juveniles as a function of climatic conditions.

The anthropophytisation processes pose a real threat to the phytodiversity on the territory of Ukraine. To study the interpopulation variability and to analyze the factors leading to the excessive increase in quantity of the adventive species individuals in the conditions of anthropogenic transformation, we took as a model the invasion species on the territory of Ukraine: Solidago canadensis L. and Solidago gigantean Ait. According to the study of the morphological signs variability in local populations S. canadensis and S. gigantea in different ecological conditions, we have revealed that the morphometric signs (length of the ramet, number of leaves, length of inflorescences, number of flowers in the inflorescences) of the S. canadensis ramets are characterized by medium and high intrapopulations variability (V = 11.46-68.67 %), and S. gigantea ramets are characterized by insignificant and high levels of intrapopulation variability (V = 7.01-90.04 %), which correlates with unfavourable conditions of anthropogenically transformed habitats. According to the study results, we have discovered that the depressive vitality type, and, correspondingly, the low vitality level is common for the local populations of S. canadensis for ruderal biotopes of anthropogenic herb stands, ruderal biotopes of fallows on sand, highly artificial broadleaved deciduous forestry plantations and fruit and nut tree orchards. Such a vitality type of S. canadensis populations is probably explained by the high level of digression of the above-mentioned biotopes. The local population of the ruderalized thickets of bushes is characterized by the comparatively high value of the vitality index, which is due to the favorable edaphic conditions. On the other hand, the local populations of S. gigantea of ruderal biotopes of anthropogenic herb stands, ruderal biotopes of fallows on sand, highly artificial broadleaved deciduous forestry plantations, fruit and nut tree orchards and ruderalized thickets of bushes are characterized by a prosperous vitality type and, accordingly, a high level of vitality.

In the context of climate change, in situ conservation of plant genetic resources is becoming increasingly important as it supports natural (ecological and evolutionary) adaptations of plants to the changing environment. The aim of this study was to synthesize a comprehensive general methodology for the maintenance of genetic reserve sites of medicinal plants based on the analysis of relevant legal documents, literature sources, databases, and authors’ own experience. A methodology was developed for the application of various maintenance measures for target species populations in genetic reserve sites to ensure their long-term sustainability. It uses a systematic approach to the intervention measures by grouping them into habitat-specific and factor-specific ones, and follows the specific principles of biodiversity conservation, such as the concept of ecosystem, priority of in situ conservation, caution and validity of decision-making, and regional approach. An extensive discussion on major intervention measures is provided. The methodology is intended to be used as a tool for the preparation and implementation of management plans of individual medicinal plant genetic reserve sites by the responsible agencies and protected area managers and is directly linked to the implementation of the EU (European Union) Biodiversity Strategy to 2030 at the national level.

Summary We report a four-year study of the dynamics of a population of Salvia lyrata L., growing in a greenhouse. The study exemplifies the population cage approach, which has been the basis of many long-term studies of dynamics of animal populations for over 50 years, but which has been overlooked by plant population biologists. The cohort of plants that founded the population had a very high probability of survival and, as adults, produced the greatest numbers of seeds and seedlings. Thereafter, the numbers of individuals in each stage class declined. This decline appeared to be a consequence of density-dependent processes. At the conclusion of the study, the population density was far lower than at the onset. The behaviour of the population differed from that of the population of S. lyrata studied in a nearby mown field in several respects, including timing of seedling emergence, average size of individuals and final density. Likely causes of these differences are discussed. We recommend the use of population cages in further studies of plant populations. Because it facilitates long-term observation, this approach can be of great use in elucidating the dynamic consequences of demography.

Soil microorganisms influence a variety of processes in plant communities. Many theoretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequency-dependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among 15 pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequency-dependent dynamics that stabilize plant interactions, they simultaneously generate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is to often favor species exclusion over coexistence, a result that becomes evident only by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity.

Choosing appropriate estimator that provides an accurate and precise prediction of plant population’s density is vital specifically when different density intensities and distribution patterns are concerned. Therefore, the efficiency of plotless plant density estimators for the various spatial patterns found in nature have been examined using a simulated population based on an observed population of Astragalus microcephalus in a semi-arid environment. We first surveyed the density of A. microcephalus in the field to have an estimation of the real density of the species (control method). Then a simulation scheme in three density intensities (low (mean−SD), moderate (equal to mean) and high (mean + SD)) and three distribution patterns (random, regular and aggregated) was drawn. Seven distance-based plant estimators were applied to evaluate their efficiency in the three density intensities and also distribution patterns within eight 40 × 100 m sampling units of the simulated scheme (repeats). The predictive precision and accuracy of the estimators in various density intensities and distribution patters were evaluated using the ideal point error-index and comparing the estimators predicted values with the controls (real densities). Angle Order (AO) and Third Closest Individual (TCI) in regular, TCI and Point Centered Quarter (PCQ) in random and AO in aggregate distribution pattern was the best plotless density estimators of plant populations. Overall, TCI, AO and PCQ were the most accurate and precise estimators of density among the seventh studied estimators in different density intensities and distribution patterns. Using these two estimators is recommended to achieve an unbiased estimation of plant population’s density.

Plant densities in Mid-South U.S. soybean, Glycine max (L.) Merr., fields can vary greatly due to a wide range of factors, although soybean yields are generally insensitive to variations in density. Currently, it is unknown if yield loss from insect-related defoliation varies across different soybean stand densities. Soybean was planted in Starkville and Stoneville, MS, in 2016 and 2017 at five seeding rates ranging from 123,500 to 420,070 seed/ha in 74,130 seed/ha increments. Each seeding rate contained a nondefoliated plot and a plot that was defoliated 67% at the R1 growth stage. Defoliated plants had a greater leaf expansion rate from R1 to R3 than nondefoliated plants. Defoliation reduced yield where plant densities were

Soil microorganisms influence a variety of processes in plant communities. Many the-oretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequency-dependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among fifteen pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequency-dependent dynamics that stabilize plant interactions, they simultaneously mediate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is often to favor species exclusion over coexistence, a result that only becomes evident by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity.

International audience; In climate change ecology, simplistic research approaches may yield unrealistically simplistic answers to often more complicated problems. In particular, the complexity of vegetation responses to global climate change begs a better understanding of the impacts of concomitant changes in several climatic drivers, how these impacts vary across different climatic contexts, and of the demographic processes underlying population changes. Using a replicated, factorial, whole‐community transplant experiment, we investigated regional variation in demographic responses of plant populations to increased temperature and/or precipitation. Across four perennial forb species and 12 sites, we found strong responses to both temperature and precipitation change. Changes in population growth rates were mainly due to changes in survival and clonality. In three of the four study species, the combined increase in temperature and precipitation reflected nonadditive, antagonistic interactions of the single climatic changes for population growth rate and survival, while the interactions were additive and synergistic for clonality. This disparity affects the persistence of genotypes, but also suggests that the mechanisms behind the responses of the vital rates differ. In addition, survival effects varied systematically with climatic context, with wetter and warmer + wetter transplants showing less positive or more negative responses at warmer sites. The detailed demographic approach yields important mechanistic insights into how concomitant changes in temperature and precipitation affect plants, which makes our results generalizable beyond the four study species. Our comprehensive study design illustrates the power of replicated field experiments in disentangling the complex relationships and patterns that govern climate change impacts across real‐world species and landscapes.

Masting is defined as the intermittent highly variable production of seed in a plant population. According to reproductive modes, that is, sexual and asexual reproduction, masting species can be separated into three groups, that is, (1) species, for example, bamboo, flower only once before they die; (2) species, for example, Fagus, reproduce sexually; and (3) species, for example, Stipa tenacissima, reproduce both sexually and asexually. Several theories have been proposed to explore the underlying mechanisms of masting. However, to our knowledge, no theory has been found to explain the mechanism of masting species that reproduce both sexually and asexually. Here we refine the Resource Budget Model by considering a trade-off between sexual and asexual reproduction. Besides the depletion efficient (i.e., the ratio of the cost of seed setting and the cost of flowering), other factors, such as the annual remaining resource (i.e., the rest of the resource from the photosynthetic activity after allocating to growth and maintenance), the trade-off between sexual and asexual reproduction, and the reproductive thresholds, also affect masting. Moreover, two potential reproductive strategies are found to explain the mechanisms: (1) When the annual remaining resource is relatively low, plants reproduce asexually and a part of the resource is accumulated as the cost of asexual reproduction is less than the annual remaining resource. Plants flower and set fruits once the accumulated resource exceeds the threshold of sexual reproduction; (2) when the annual remaining resource is relatively high, and the accumulated resource surpasses the threshold of sexual reproduction, masting occurs. Remarkably, under certain depletion efficient, more investigation in sexual reproduction will lead plants to reproduce periodically. Additionally, plants investigate less resource to reproduce periodically when depletion efficient keeps increasing as plants can reproduce efficiently. Overall, our study provides new insights into the interpretation of masting, especially for species that reproduce both sexually and asexually.

Non-nutritive phytochemicals (secondary metabolites and fibre) can influence plant resistance to herbivores and have ecological impacts on animal and plant population dynamics. A major hindrance to the ecological study of these phytochemicals is the uncertainty in the compounds one should measure, especially when limited by cost and expertise. With the underlying goal of identifying proxies of plant resistance to herbivores, we performed a systematic review of the effects of non-nutritive phytochemicals on consumption by leporids (rabbits and hares) and cervids (deer family). We identified 133 out of 1790 articles that fit our selection criteria (leporids = 33, cervids = 97, both herbivore types = 3). These articles cover 18 species of herbivores, on four continents. The most prevalent group of phytochemicals in the selected articles was phenolics, followed by terpenes for leporids and by fibre for cervids. In general, the results were variable but phenolic concentration seems linked with high resistance to both types of herbivores. Terpene concentration is also linked to high plant resistance; this relationship seems driven by total terpene content for cervids and specific terpenes for leporids. Tannins and fibre did not have a consistent positive effect on plant resistance. Because of the high variability in results reported and the synergistic effects of phytochemicals, we propose that the choice of chemical analyses must be tightly tailored to research objectives. While researchers pursuing ecological or evolutionary objectives should consider multiple specific analyses, researchers in applied studies could focus on a fewer number of specific analyses. An improved consideration of plant defence, based on meaningful chemical analyses, could improve studies of plant resistance and allow us to predict novel or changing plant-herbivore interactions.

Mutualistic interactions like those established between plants and mycorrhizal fungi or seed dispersers are key drivers of plant population dynamics and ecosystem functioning; however, these interactions have rarely been explored together. We assembled a tripartite fungi–plant–disperser network in the Gorongosa National Park—Mozambique, to test (1) if diversity and importance of plant mutualists above- and belowground are correlated, and (2) whether biotically and abiotically dispersed plants are associated with distinct arbuscular mycorrhizal fungi (AMF). We quantified seed dispersal by animals for 1 year and characterized the AMF of 26 common plant species. Sixteen plant species were dispersed by 15 animals and colonized by 48 AMF virtual taxa (VT), while the remaining 10 plant species were not dispersed by animals and associated with 34 AMF VT. We found no evidence for a correlation between the number of plant partners above- and belowground or on plant specialization on both types of partners. We also found no evidence for differentiation of AMF communities between biotically and abiotically dispersed plants. Our results suggest that the establishment of plant interactions with seed dispersers and mycorrhizal fungi is largely independent and that both biotically and abiotically dispersed plants seem to associate with similar communities of AMF.

The paper considers indicators of the dynamics of plant communities with Paeonia tenuifolia before and after fire impact. Studies were conducted in the Khvalynsky National Park (forest-steppe zone of Russia) in 2008–2018. The authors conducted a complex study in burned and unburned plant communities. An assessment of the effects of fire impact and the development of a post-fire action plan were considered in the Protected Area. The plant community Paeonia tenuifolia + Calamagrostis epigejos + Adonis vernalis – Potentilla volgarica burned down in 2009. The plant community Paeonia tenuifolia + Stipa pennata + Adonis vernalis – Anemone sylvestris was unburned. To characterise plant communities with Paeonia tenuifolia and its coenopopulations, we used standard geobotanical description methods. Sixty seven vascular plant species were part of the post-fire phytocoenosis. Of them, 14 species are included in the Red Data Book of the Saratov region. Changes in the post-fire plant community have occurred in the following order: 1) Paeonia tenuifolia + Calamagrostis epigejos + Adonis vernalis – Stipa pennata (in 2008) → 2) Paeonia tenuifolia + Elymus repens + Stipa pennata + Adonis vernalis + Thalictrum simplex (in 2010) → 3) Paeonia tenuifolia – Stipa pennata – Calamagrostis epigejos + Festuca valesiaca +Phleum pratense + Poa bulbosa + Prunus tenella (in 2011) → 4) Paeonia tenuifolia + Adonis vernalis + Stipa pennata (in 2015, 2017, 2018). After the fire influence on a plant community, the following changes took place: 1) annuals and ruderal plant species appeared and increased their abundance; 2) the ratio of dominant species has changed. In 2012–2018, the phytocenotic role of Calamagrostis epigejos decreased, while the coverage and abundance of Stipa pennata increased at the same period. The abundance dynamics of Paeonia tenuifolia decreased in 2010, while in 2015–2018, its value gradually increased. The species richness of the post-pyrogenic plant community varied from 20 species in the first post-fire year to 38 species in the last study year. In the first post-fire year, the families Poaceae (six species), Leguminosae plants (three species), Rosaceae plants (three species) occupied the leading positions. During the post-pyrogenic succession, the dominant position of the listed families was not changing. Species of Compositae, Poaceae, Ranunculaceae families prevailed in the unburned plant community. Steppe plants dominated in the post-fire plant community: Stipa pennata, Adonis vernalis, and Paeonia tenuifolia. The leading ecologic-coenotic groups were steppe plants (70%), meadow plants (16%), forest plants (5%), and ruderal plants (9%). Weed-steppe plants were indicators of habitat disturbance by human activities. Among weed-steppe plants, there were Arenaria serpyllifolia, Viola rupestris, Erysimum canescens, Verbascum lychnitis. Gradient analysis of environmental conditions showed that the highest value of the vitality index (IVC = 1.15) corresponds to the best conditions for the growth and survival of the Paeonia tenuifolia population in the post-fire community. In the control site, the vitality index (IVC = 0.85) corresponded to unfavourable conditions for plant development. We studied the age spectra of the natural Paeonia tenuifolia populations in the burned and unburned communities. We showed that both populations were normal, complete, and young. The fire-damaged populations were younger than the populations in the unburned communities. We suggest the need of comprehensive monitoring studies to properly assess the fire effects and subsequent management actions for the vegetation restoration after fire influence.

Little is known about the network structure of competition in large populations of plants, despite the importance of such knowledge for understanding population dynamics. In this study, we used complex network analysis to examine temporal changes in the network structure of competition in an even-aged multi-individual stand of the Sakhalin fir Abies sachalinensis in Hokkaido, Japan. Using census data, which were measured over 30 years (1948–1978; seedlings were planted in 1929), on the sizes and locations of these plants, we regarded a plant as a node and competition between plants as a link. We then introduced two indices, the binary and weighted out-degrees (BO and WO, respectively), to interpret complicated plant interactions. The BO of a plant represents the number of links from the target plant to its neighbors, and the WO is the total strength of competition from the target plant to its neighbors. The analysis showed that the distributions of BO and WO were heavy-tailed in all years and that large plants had large BO and WO. These results suggest that only a few (i.e., large) plants have a very large impact on the growth and survival of a much larger number of neighboring plants and thus on population dynamics, whereas most of the others (i.e., small and medium-sized plants) have only a small impact on a few neighbors. By introducing binary and weighted connectivities (BC’ and WC’, respectively), we were able to identify the size classes of neighbors with which the target plant preferentially and strongly competed. The BC’ and WC’ results showed that large plants competed preferentially and more strongly with other large plants in 1948, but they competed more strongly with small plants after 1963. These results clarify targets of the very large impact of large plants, as shown by the results of BO and WO: the impact was exerted on the growth and survival of other large plants in 1948, whereas the impact was exerted on those of small plants after 1963. Our study demonstrates that the statistical properties of the competition network structure, which have been largely ignored in plant competition research, are important for understanding plant population dynamics.

Background: Estimation of abundance in vegetation sampling involving observers is almost always characterised by observer error, although such error is rarely reported.Aims: To quantify observer error in population estimation of the rare plant species Physaria filiformis in Missouri, USA.Methods: The abundance of P. filiformis was estimated within 25-m2 plots by six trained observers with varying experience levels over 10 years. Observers assigned plots to six predefined density classes. A total of 477 plots were estimated annually, and actual counts were conducted on ca. 10% of the plots to assess per cent agreement of estimates with counts.Results: Over a third of the estimates of plant abundance evaluated for accuracy (36.4%) deviated from exhaustive counts. The majority of the misestimates were underestimates by one density class (29.4%). The number and type of misestimates varied systematically with density class.Conclusions: Observer error could be explained to some degree by variation in population...

Patchy landscapes select for invasiveness Invasive species are ubiquitous in human-dominated landscapes, yet we have only limited understanding of their ecological and evolutionary dynamics. Williams et al. used an experimental system with the model plant species Arabidopsis thaliana to examine how evolution affects the spread of plant populations through landscapes of varying patchiness. Plant height and dispersal ability evolved more rapidly in patchier experimental landscapes, suggesting that fragmentation can select for more rapid invasion velocity. Hence, evolution may need to be taken into account in predictions of future invasion rates. Science , this issue p. 482

Rangeland degradation continues in Australia, China and elsewhere. The stocking rate/animal production relationship has been a successful concept for pastoralists wanting to avoid degradation and/or raise incomes. However, there are no means available of alerting pastoralists to the approach of critical thresholds that would ‘flip’ rangelands into alternative states when grazing-stressed. Critical threshold forecasting for avoiding degradation (and seizing restoration opportunities) could be made available online. Research has yet to find, assemble and test the set of indicators needed to forecast the approach of critical thresholds envisaged in State-and-Transition thinking. Forecasting at paddock, property and regional scales would have to involve high-performance computing because the thresholds will be space and time dependent. The case for Australia and China to contribute cooperatively to this research effort rests on the large number of contrasting rangeland ecosystems across the two countries that represent rangelands globally. A proven history of past collaboration is extant with existing research programs on plant population dynamics, landscape patchiness/leakiness and soil biota status, and their responses to the separate and combined effects of climate and grazing animals. The road to adoption would involve partnerships with pastoralists throughout the process, remote sensing to identify approaching thresholds in real time, application of high-performance computing and possibly artificial intelligence, and packaging of forecasts for different socio-economic rangeland systems.

Paniw, M. 2019. Perspectives from animal demography on incorporating evolutionary mechanism into plant population dynamics. Ecosistemas 28(1):60-68. Doi.: 10.7818/ECOS.1640 With a growing number of long-term, individual-based data on natural populations, it has become increasingly evident that environmental change affects populations through complex, simultaneously occurring demographic and evolutionary processes. Analyses of population-level responses to environmental change must therefore integrate demography and evolution into one coherent framework. Integral projection models (IPMs), which can relate genetic and phenotypic traits to demographic and population-level processes, offer a powerful approach for such integration. However, a rather artificial division exists in how plant and animal population ecologists use IPMs. Here, I argue for the integration of the two sub-disciplines, particularly focusing on how plant ecologists can diversify their toolset to investigate selection pressures and eco-evolutionary dynamics in plant population models. I provide an overview of approaches that have applied IPMs for eco-evolutionary studies and discuss a potential future research agenda for plant population ecologists. Given an impending extinction crisis, a holistic look at the interacting processes mediating population persistence under environmental change is urgently needed.

Species monitoring is a valuable tool that can be used to answer a wide range of questions directly related to species conservation, management, and population improvement. We monitored the only remaining population of Lotus kunkelii on a monthly basis over 3 years to reveal important characteristics of the population that could help protect it. In this study, the main hypothesis to be tested is whether the population of L. kunkelii is stable or not. The study site is located in Gran Canaria. Monthly censuses of the population recording size (height and diameter), mortality, regeneration, and presence of reproductive structures in each individual were carried out, and this monthly information of variables was correlated with climatic variables. The population is growing (from 105 to more than 200 individuals during the studied time) at a slow pace and is restricted by the environmental conditions of its surroundings (the proximity of the population to the sea that cushions the weather conditions), but we also determined high vulnerability of the species with respect to flooding and heavy rain. However, the population can be considered endangered due to its low number of individuals, and also because it is restricted to a very small area of land. We suggest that to conserve the population new individuals should be protected from grazing where the natural population is found. Finally, the climatic changes predicted by the IPCC in this area should also be considered in future conservation plans.

International audience; Masting is the highly variable and synchronous production of seeds by plants. Masting can have cascading effects on plant population dynamics and forest properties such as tree growth, carbon stocks, regeneration, nutrient cycling, or future species composition. However, masting has often been missing from forest models. Those few that simulate masting have done so using relatively simple empirical rules, and lack an implementation of process-based mechanisms that control such events. Here we review more than 200 published papers on mechanistic formulations of masting, and summarize how the main processes involved in masting and their related patterns can be incorporated in forest models at different degrees of complexity. Our review showed that, of all proximate causes of masting, resource acquisition, storage and allocation were the processes studied most often. Hormonal and genetic regulation of bud formation, floral induction, and anthesis were less frequently addressed. We outline the building blocks of a general process-based model of masting that can be used to improve the oversimplified functions in different types of forest models, and to implement them where missing. A complete implementation of masting in forest models should include functions for resource allocation and depletion, and for pollination, as regulated by both forest structure and weather in the years prior to seed production. When models operate at spatio-temporal scales mismatched with the main masting processes, or if calibration data are not available, simulation can be based on parameterizing masting patterns (variability, synchrony, or frequency). Also, observed masting patterns have the potential to be used as “reality checks” for more process-based forest models wishing to accurately reproduce masting as an emergent phenomenon.

Plant population dynamics is fundamental to identify which parts of the life cycle are important when designing management actions. In this study, the short-term population dynamics of Helianthemum caput-felis (Cistaceae), a perennial plant distributed throughout the western Mediterranean Basin, was investigated by monitoring 98 permanent plots randomly placed along the overall distribution range for three years (2013–2015). Demographic surveys were analysed by Integral Projection Models (IPMs), and the analysis of population growth rates, elasticities, and life table response experiment (LTRE) analyses were performed. Under deterministic conditions, the H. caput-felis population showed a slight increase in the first censuses, but a general population decline followed. This trend was probably due to the shrinkage of plants in the last year, which correlated negatively with reproductive traits. Despite this decline, the population was at equilibrium under the simulated environmental stochasticity. The population dynamics of H. caput-felis followed the general pattern typical for long-lived Mediterranean plants: populations with growth rates closer to the equilibrium in the long term, determinant role of the survival-growth transitions for the population growth rate, slow growth and stasis, longevity of established individuals, shrinkage of medium-large plants, low recruitment rate, high generation times and mean long lifespans. The results of this study, which highlight how conservation measures can be focused on protecting and increasing the number of plants of medium-large size, provide important information for the planning management conservation actions for H. caput-felis and for several Mediterranean plants that show a similar life-history strategy.

Cypripedium calceolus is considered as one of the flagship plant species of nature conservation. It is legally protected throughout Eurasia. Due to its wide distribution range, this Eurasian species could be considered as Least Concern, Near Threatened, Vulnerable, Endangered or Critically Endangered taxon. We performed an analysis of the status for some C. calceolus populations in Central Russia located in the Republic of Mordovia, with emphasis on populations situated in the federal protected areas. The aim of our study was to asses the modern state and the endangerment of C. calceolus populations. The environment conditions and species composition in five habitats with rare species in Mordovia were compared using phytoindication methods. Changes in stage spectrum and total abundance dynamics in C. calceolus populations over 2011-2016 were estimated and compared with available data from other locations within species’ range. Reproductive ability of populations from the federal protected area, Mordovia State Nature Reserve, were studied. The results showed that C. calceolus grows in three habitat types that differed in environment conditions and floristic composition. Convallaria majalis was the only species registered in all studied locations, together with C. calceolus. In Central Russia this species occurs in broad-leaved, coniferous and mixed forests. The three populations of C. calceolus within the Mordovia State Nature Reserve and National Park “Smolny” were characterized by the dominance of vegetative individuals in stage spectrum, while generative plants predominated in two other populations located in mixed forests. No correlation between total abundance of individuals and stage spectrum in populations of threatened species has been found over the study period. The population in Mordovia Reserve showed a higher fruit set (36.7% as a mean) than others reported within its range. Continued population monitoring of C. calceolus in Central Russia from different habitat types is suggested. Generalization of jointly obtained demographic, ecological, phytocoenological data will be appropriate in order to develop measures for conservation and management of C. calceolus habitats.

The subject of the research was the population of orchid growing in the area of Pierzchno in Wielkopolska. This position was found in 2001 where two kinds of orchids were recorded – Orchis morio and Dactylorhiza majalis. Male orchid occurs in the particular position in this geographical region. Quite numerous population of Dactylorhiza majalis (broad-leaved marsh orchid) and counting only a few specimens of the population of Orchis morio were followed in 2013–2015. The research concerned both individual and group features. During this period, we observed a clear progression of broad-leaved marsh orchid population. It resulted in an increase in the number of ramets and the area occupied by it. In the first year of research two experimental plots were extracted and in the next growing season, a third surface was found, occupied by the species. Locating juveniles in the second season also confirms the population dynamics. In the last year of observation, orchids appeared only on the second surface, which substantially increased its dimensions. Unfortunately, in the case of populations of the male orchid clear regression was noted because fewer individuals grew from year to year. On the meadow nearby Pierzchno favourable living conditions were found for Dactylorhiza majalis and unfavourable ones for Orchis morio, which could lead to the disappearance of this population. key words: Orchis morio, Dactylorhiza majalis, population, individual features, group features, Pierzchno

Background and aims – Calcareous grasslands are local biodiversity hotspots in temperate regions that suffered intensive fragmentation. Ecological restoration projects took place all over Europe. Their success has traditionally been assessed using a plant community approach. However, population ecology can also be useful to assess restoration success and to understand underlying mechanisms. Methods – We took advantage of three calcareous grassland sites in Southern Belgium, where reference parcels coexist with parcels restored in the late twentieth century and with more recently restored parcels. We evaluated the colonization stage of three specialist species ( Sanguisorba minor, Potentilla neumanniana and Hippocrepis comosa ) using occurrence data. We also measured the reproductive traits of 120 individuals per species and compared components of fitness between recent restorations, old restorations and reference habitats. Key results – We found that the occurrence of H. comosa was similar in the different restoration classes, whereas both P. neumanniana and S. minor occurrences decreased from reference grasslands to recent restorations. In contrast, these two latter species exhibited a much higher reproductive output in recent restorations, thanks to an increased production of flowers and seeds. Conclusions – Our results suggest that, during colonization of recently restored calcareous grasslands, favourable environmental conditions, low competition and sufficient genetic mixing may lead to an increased fitness of individuals and a faster population growth than in the reference habitat. These results demonstrate how population processes can increase ecological resilience and highlight the interest of a population-based approach to assess the success of ecological restoration.

Accumulating evidence suggests that density dependence, whether at early or late life stages, is an important mechanism regulating plant population structure. However, the opposing effects of habitat heterogeneity and species-level variation might have confounded the prevalence of density dependence in natural forests. These compatible ideas were rarely considered simultaneously. In this study, we applied a spatial statistical technique to examine (i) the prevalence of density dependence at late life stages after controlling for habitat heterogeneity and (ii) the relationships between species traits and the strength of density dependence in a newly established, 25 ha subtropical mountain forest plot in central China. Of the 88 (75%) tree species analyzed, 66 were found to exhibit density dependence predominantly at very close distances among neighbors in the species-rich subtropical forest. In addition, the strength of density dependence was associated with species traits. Our findings identified strong density dependence among trees that had greater stature and were rarer. We concluded that density dependence was a prevalent mechanism for regulating the population structure of most tree species and both habitat heterogeneity and species-level variation played crucial roles in shaping the strength of density dependence in natural forests.

Data on the spatial distribution of a plant population among administrative areas is useful for various purposes. In this study, I analyzed the spatial distribution of the geographical distances of Carex siderosticta at Mt. Geumjeong and Mt. Ahop in Korea. The aim was to test a spatial structure within two populations of C. siderosticta. Most natural plots of C. siderosticta are not uniformly distributed in the forest community; for example, uniform plots were aggregately distributed within a space of 6.0 m × 6.0 m. When the sampling plots were larger than 6.0 m × 12.0 m, the individuals of C. siderosticta were aggregately distributed. The neighboring patches of C. siderosticta were predominantly 7.5 m to 9.0 m apart, on average; however, if the natural populations were disturbed by human activities, the aggregation occurred in shorter distances than a scale of 9.0 m. Moran"s I of C. siderosticta significantly differed from the expected value in only 16 of 40 cases (40%). In conclusion, the geographical distribution of C. siderosticta is not even, with varying degrees of size in the plots, while human activities give rise to density effects in the plots at both Mt. Geumjeong and Mt. Ahop in Korea.

An experiment was carried out to assess the growth and development of quality protein maize (QPM) genotypes to various plant populations under different irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11 o 39’ N, 08 o 20’ E) and 500 m above sea level) for three years, 2007, 2008 and 2009 during dry seasons to study the effect of three maize ( Zea mays L .) genotypes (TZE - W Pop X 1368, EV - DT W99 STR and DMR - ESRW), four plant populations (33,333, 44,444, 55,555 and 66,666 plants ha - 1 ) and three irrigation scheduling regimes (40, 60 and 80 centibars soil moisture tension) on the growth and development of QPM. This was a three trial experiment with factors arranged in a split plot design, whereby genotype and irrigation scheduling

Feedbacks between plants and soil communities may be elusive, yet they have far-reaching consequences for plant physiology, competition and community structure. Plant–soil feedbacks (PSFs) are plant-mediated changes to soil properties that ultimately influence the performance of the same or other plants (Van der Putten et al., 2013). These PSFs may be mediated by root-associated organisms (hereafter, root-mediated feedbacks) or saprotrophic organisms and associated litter characteristics (hereafter, litter-mediated feedbacks). However, we know little about the potential mechanistic linkages and relative strengths between these distinct, but connected, processes as root- and litter-mediated feedbacks have generally been studied independently from each other. This is despite the fact that root-associated organisms and saprotrophs can interact through various mechanisms, either directly or as mediated by the plant (e.g. Wardle, 2006). By using a trait-based approach,Ke et al. (in this issue of New Phytologist, pp. 329–341) make an important contribution by integrating root- and litter-mediated PSFs in a nitrogen (N)-based, stage-structured plant population and microbial community model. Their approach allows us to start peeking into the ‘black box’ thereby promoting a better understanding of how PSFs operate interactively. Ke et al. considered various plant traits (e.g. decomposability), but also incorporated trait variation in the physiology, demography and composition of the soil microbial community, and tested their separate and interactive effects on PSF strength in a comprehensive simulation framework. Finally, they used empirical evidence from the literature to support their model predictions.

A substantial increase of area, numbers and density in populations of trees, shrubs and dwarf shrubs – Picea abies, Pinus mugo, Alnus viridis, Juniperus sibirica, Vaccinium-species is marked in the high-mountain zone of the Ukrainian Carpathians. The flowering and fruit maturation at higher elevations of alpine belt are characteristic for the number of species of different life forms: Vaccinium myrtillus, Centaurea mollis, Homogyne alpina, Helictotrichon versicolor, Potentilla aurea. This trend is related to warming and prolongation of growing season and it is peculiar for the species with ecological and climate optima in the forest and subalpine belts, whereas the conditions of the alpine belt are extreme for them. The expanding populations of rare and endemic plant species: Loiseleuria procumbens, Senecio carpaticus, Heracleum carpaticum, Rhododendron myrtifolium, Callianthemum coriandrifolium, Galium pawlowskii have been found. However, the alpine and arctic-alpine species: Oreochloa disticha, Rhodiola rosea, Carex curvula etc. demonstrate negative dynamics.The described processes are mainly the result of successions and plant cover restoration due to grazing termination and climate warming. The impact of plant cover restoration and raising of the timberline on populations of investigated species at high mountain zone of protected areas often cannot be separated from the impact of global warming.

In this paper we present a mathematical model describing the interaction of two species, a plant population and an insect population, the latter being divided in two subgroups: novice and expert pollinators. We analyze the system and show the existence of a single nontrivial equilibrium, which is stable and represents a state of mutual benefit for all species involved. We show some numerical simulations of the global stability.