Characteristics and Main Trends of Anthropogenic Florogenesis in the Southern Volga Uplands

The entire range of aspects of anthropogenic florogenesis in the southern part of the Volga Uplands is addressed. Trends in the anthropogenic dynamics of local flora in the last 100 years have been identified. A shift 50–100 km northward of the southern border of natural habitats of some boreal species (Antennaria dioica (L.) Gaertn., Maianthemum bifolium (L.) F.W. Schmidt, Pyrola rotundifolia L., etc.) has been noted. Data on the adventive flora and modern migration paths of the plants within the study area are provided. The adaptive activity of aboriginal species in relation to the entire range of anthropogenic habitats of the region is characterized. Information on findings of protected plant species in anthropogenic biotopes is provided. Overall, flora aridization and xerophytization have been noted, as has an increased role of tree and shrub life forms in the anthropogenic florogenesis. It is proposed to use a method based on the identification of anthropochorophilic elements in the aboriginal flora to forecast the adaptation of flora to the conditions of anthropogenic habitats.     

Naturalization of introduced plants: ecological drivers of biogeographical patterns

CONTENTS: Summary 383 I. Introduction 383 II. The introduction-naturalization-invasion continuum for conceptualizing biological invasions 384 III. The biogeographical background for studying naturalization: variation among populations and regions 385 IV. Factors determining naturalization in plants 388 Acknowledgements 392 References 392 SUMMARY: The literature on biological invasions is biased in favour of invasive species - those that spread and often reach high abundance following introduction by humans. It is, however, also important to understand previous stages in the introduction-naturalization-invasion continuum ('the continuum'), especially the factors that mediate naturalization. The emphasis on invasiveness is partly because most invasions are only recognized once species occupy large adventive ranges or start to spread. Also, many studies lump all alien species, and fail to separate introduced, naturalized and invasive populations and species. These biases impede our ability to elucidate the full suite of drivers of invasion and to predict invasion dynamics, because different factors mediate progression along different sections of the continuum. A better understanding of the determinants of naturalization is important because all naturalized species are potential invaders. Processes leading to naturalization act differently in different regions and global biogeographical patterns of plant invasions result from the interaction of population-biological, macroecological and human-induced factors. We explore what is known about how determinants of naturalization in plants interact at various scales, and how their importance varies along the continuum. Research that is explicitly linked to particular stages of the continuum can generate new information that is appropriate for improving the management of biological invasions if, for example, potentially invasive species are identified before they exert an impact.     

Survival rates in the Czech Republic of introduced plants known as wool aliens

The paper analyses an unintentional experiment conducted 40 years ago with species termed wool aliens which were observed in employee garden allotments of a wool-processing factory in Brno, Czech Republic. The waste from processing was used as a garden fertilizer, and alien species were recorded by Dvořák and Kühn (1966) Zavlečené rostliny na pozemcích přádelny vlny ‘Mosilana’ n.p. v Brně. Preslia 38: 327–332. The survival of these species was assessed by their occurrence in the current alien flora of the Czech Republic. Of the 56 species introduced in the 1960s and classified as wool aliens, 18 are still present in the Czech alien flora. The remaining 38 species are considered extinct, i.e. alien plants not capable of long-term survival in the country. The resulting survival rate of wool aliens is 22.1%. Three species on the list (5.4%) were clearly capable of naturalization. Compared to the other alien flora of the Czech Republic, wool aliens were disproportionally introduced from Australia, Africa and South and Central America. Species from Europe and Africa tended to survive the best. Grasses were most strongly represented, contributing 62.5% to wool alien species but only 7.9% to the total Czech neophyte flora. All surviving species were annuals, whereas none of the perennials survived; the survival rate in annuals was 37.5%. Survival of species introduced with wool was significantly comparable to their performance in the UK and in Central Europe, indicating that survival is not determined by mere chance and that the same species tend to be successful elsewhere in Europe. Maximum height and the month of first flowering were not significantly related to the species survival. The role of specific events in the enrichment of alien floras is discussed.     

Observations on changes in abundance of questing Ixodes ricinus,castor bean tick,over a 35‐year period in the eastern part of its range (Russia,Tula region)

Ixodes ricinus (Acari: Ixodidae) L. transmit a wide variety of pathogens to vertebrates including viruses, bacteria and protozoa. Understanding of the epidemiology of tick‐borne infections requires basic knowledge of the regional and local factors influencing tick population dynamics. The present study describes the results of monitoring of a questing I. ricinus population, conducted over 35 years (1977–2011) in the eastern, poorly studied part of its range (Russia, Tula region). We have found that the multiannual average abundance of ticks is small and varies depending on the biotope and degree of urban transformation. Tick abundance for the first 14 years of observations (1977–1990) was at the lower limit of the sensitivity of our methods throughout the study area (0.1–0.9 specimens per 1‐km transect). In the following 21 years (1991–2011), a manifold increase in abundance was observed, which reached 18.1 ± 1.8 individuals per 1‐km transect in moist floodplain terraces, and 4.8 ± 0.9 in xerophylic hill woods. Long‐term growth of tick abundance occurred in spite of a relatively constant abundance of small mammals and only minor fluctuations in the abundance of large wild animals. Climate and anthropogenic changes appear to be the main contributors to increased abundance of the tick.     

Ergasiophygophytes and xenophytes of East Asiatic origin in Adjaria a stimulus to new terminology,especially for ergasiophygophytes

Studies of the Adjarian flora resulted in a detailed classification of the ergasiophygophytes, based mainly on the degree of their naturalization: (1) The ephemeroergasiophygophytes display unstable naturalization both in artificial and natural habitats, and disappear after only a few growing seasons. (2) The deuteroergasiophygophtes show stable naturalization in anthropogenic habitats. (3) The protoergasiophygophytes are distinguished by uncertain stability of naturalization in natural habitats, and, if firmly naturalized on a certain spot, they lack any tendency to further spreading. (4) The autergasiophygophytes tend to spread in natural habitats. (5) The aggressive ergasiophygophytes transform natural vegetation in new plant communities, and can become dominant species in these communities. New terms, viz. emphemeroxenophytes, protoneophytes, non-aggressive neophytes, slightly aggressive neophytes, and postneophytes with vegetative reproduction have also been introduced to express diverse features of the xenophytes.     

A phylogenetic analysis of the British flora sheds light on the evolutionary and ecological factors driving plant invasions

Darwin's naturalization hypothesis predicts that invasive species should perform better in their novel range in the absence of close relatives in the native flora due to reduced competition. Evidence from recent taxonomic and phylogenetic‐based studies, however, is equivocal. We test Darwin's naturalization hypothesis at two different spatial scales using a fossil‐dated molecular phylogenetic tree of the British native and alien flora (ca. 1600 species) and extensive, fine‐scale survey data from the 1998 Countryside Survey. At both landscape and local scales, invasive species were neither significantly more nor less related to the native flora than their non‐invasive alien counterparts. Species invasiveness was instead correlated with higher nitrogen and moisture preference, but not other life history traits such as life‐form and height. We argue that invasive species spread in Britain is hence more likely determined by changes in land use and other anthropogenic factors, rather than evolutionary history. Synthesis. The transition from non‐invasive to invasive is not related to phylogenetic distinctiveness to the native community, but instead to their environmental preferences. Therefore, combating biological invasions in the Britain and other industrialized countries need entirely different strategies than in more natural environments.     

Adventive flora of Israel — Phytogeographical,ecological and agricultural aspects

73 adventive wild species occur in the flora of Israel: 39 are of tropical origin, 20 are North American. The geographical distribution pattern suggests that about two thirds of the species reached Israel through neighbouring countries, while only one third arrived directly from their countries of origin. — Three patterns of population dynamics can be recognized: accidental species (7), colonizing species (30), and species penetrating into natural habitats (3). There is insufficient information about the remaining species. — About 20 species are widespread noxious weeds which now have economic significance in Israel, 20 others are known to have similar ecological tendencies in other countries. These species soon may become aggressive weeds in Israel.     

Vegetation recovery in rural kahikatea (

Vegetation was sampled in kahikatea (Dacrycarpus dacrydioides)-dominant forest fragments having different recovery periods since grazing ceased in the Waikato region, North Island, New Zealand. Changes in vegetation were modeled against recovery periods ranging from 0–74 y and in relation to position within fragment (edge or interior). Indigenous plant species richness increased and adventive plant species (mostly pasture herbs) richness declined with increasing recovery period; small tree and sapling density and seedling ground cover increased. Fragment edges had higher adventive species richness, lower basal area, more established seedlings, lower litter cover and higher grass ground cover, than interior plots. Some indigenous species (e.g. Laurelia novaezealandiae and Myrsine australis) increased with recovery period while some adventive species (e.g. Solanum pseudocapsicum) declined. The relative basal area of Alectryon excelsus increased significantly with recovery period at edges, and that of Melicytus ramiflorus everywhere. Twenty years represents a turning point in the recovery period, with the end of the loss phase of adventive pasture species, the start of the re-establishment phase of indigenous ground layer and understorey species, and significant recovery of population structures of major species. In relatively non-weedy rural environments, retirement from grazing may be sufficient to ensure a return to near-natural states in 40–50 y.     

Population dynamics of two small pelagic fish in the central-south area off Chile: delayed density-dependence and biological interaction

It is widely believed that environmental variability is the main cause for fluctuations in commercially exploited small pelagic fish populations around the world. Nevertheless, density-dependent factors also can drive population dynamics. In this paper, we analyzed thirteen years of a relative abundance index of two clupeoids fish populations coexisting in the central-south area off Chile, namely the common sardine, Strangomera bentincki, and anchovy, Engraulis ringens. We applied the classical diagnostic tools of time series analysis to the observed time-series. Also, the realized per capita population growth rate was studied with the aim of detecting the feedback structure that is characterizing the population dynamics of the two species. The analysis suggests that population fluctuations of the two species have an important density-dependent component, displaying first-order (direct density-dependent) and second-order (delayed density-dependent) simultaneously. The density-dependent component explained 70.5 and 55.6 % of the realized per capita population growth rate of common sardine and anchovy, respectively. The deterministic skeleton model showed an asymptotic convergence to equilibrium density. In presence of a stochastic environment, fluctuations were reproduced for the species showing a component of fluctuation with a period of 4 year. The intrinsic dynamics of each species is typical of interacting species resulting from trophic interactions. It is postulated that the second-order dynamics of S. bentincki and E. ringens in central-south Chile, may be the result from interactions with a specialist predator (the fishing fleet), interacting with exogenous environmental factors.     

Effects of exotic-native species relationship on naturalization and invasion of exotic plant species

达尔文归化难题描述了外来种-本地种亲缘关系促进(预适应假说)或阻止(达尔文归化假说)外来种成功入侵的悖论。目前, 在中国仍缺少针对达尔文归化难题的研究。为系统研究外来种-本地种亲缘关系对中国外来植物入侵的影响, 该文利用线性混合效应模型从省级、市级和群落3个空间尺度以及归化、扩散和入侵3个阶段探究了外来种-本地种谱系距离和外来植物表现的关系。结果表明: 在省级和市级(区域)尺度上, 与本地种亲缘关系较近的外来植物更有可能在当地归化和扩散, 符合预适应假说的预期; 而在群落(局域)尺度上, 外来种-本地种亲缘距离与外来种是否在群落中成功定居及其入侵程度无关。该研究结果表明与本地区系亲缘较近的外来种和本地种的竞争并不强烈, 却能较好地适应本地气候环境而具有更强的归化和入侵潜力。因此, 在今后的外来植物管理和治理中需要尤其重视与本地区系亲缘关系较近的外来植物。     

外来种-本地种亲缘关系对外来植物归化和入侵的影响

达尔文归化难题描述了外来种-本地种亲缘关系促进(预适应假说)或阻止(达尔文归化假说)外来种成功入侵的悖论。目前, 在中国仍缺少针对达尔文归化难题的研究。为系统研究外来种-本地种亲缘关系对中国外来植物入侵的影响, 该文利用线性混合效应模型从省级、市级和群落3个空间尺度以及归化、扩散和入侵3个阶段探究了外来种-本地种谱系距离和外来植物表现的关系。结果表明: 在省级和市级(区域)尺度上, 与本地种亲缘关系较近的外来植物更有可能在当地归化和扩散, 符合预适应假说的预期; 而在群落(局域)尺度上, 外来种-本地种亲缘距离与外来种是否在群落中成功定居及其入侵程度无关。该研究结果表明与本地区系亲缘较近的外来种和本地种的竞争并不强烈, 却能较好地适应本地气候环境而具有更强的归化和入侵潜力。因此, 在今后的外来植物管理和治理中需要尤其重视与本地区系亲缘关系较近的外来植物。     

Transit towards floristic homogenization on oceanic islands in the south-eastern Pacific: comparing pre-European and current floras

Aim  To quantify the occurrence of processes of homogenization or differentiation in the vascular flora of six oceanic islands.
Location  Six islands in the south-eastern Pacific drawn from the Desventuradas Archipelago, Easter Island and the Juan Fernández Archipelago.
Methods  Using published floristic studies, we determined the floristic composition of each island at two different stages: (1) pre-European colonization and (2) current flora. We compared changes in the number of shared plants and the floristic similarity among islands for each stage.
Results  The number of plant species doubled from 263 in pre-European flora to 531 species currently. Only three native species became extinct, four natives were translocated among the islands and 271 plant species were introduced from outside. The frequency of plant species shared by two or more islands is higher in the post-European floras than prior to European contact, and the level of floristic similarity between islands increased slightly.
Main conclusions  Considering the low naturalization rate of alien plants, the small number of extinctions and the meagre increase in floristic similarity, these islands are undergoing a slow process of floristic homogenization.     

Naturalization of ornamental plant species in public green spaces and private gardens

Ornamental horticulture is the most important pathway for alien plant introductions worldwide, and consequently, invasive spread of introduced plants often begins in urban areas. Although most introduced ornamental garden-plant species are locally not naturalized yet, many of them have shown invasion potential elsewhere in the world, and might naturalize when climate changes. We inventoried the planted flora of 50 public and 61 private gardens in Radolfzell, a small city in southern Germany, to investigate whether local naturalization success of garden plants is associated with their current planting frequency, climatic suitability (as assessed with climatic niche modelling) and known naturalization status somewhere in the world. We identified 954 introduced garden-plant species, of which 48 are already naturalized in Radolfzell and 120 in other parts of Germany. All currently naturalized garden plants in Radolfzell have a climatic suitability probability of ≥ 0.75 and are naturalized in ≥ 13 out of 843 regions globally. These values are significantly higher than those of garden plants that have not become locally naturalized yet. Current planting frequencies, however, were not related to current naturalization success. Using the identified local naturalization thresholds of climatic suitability and global naturalization frequency, and climate projections for the years 2050 and 2070, we identified 45 garden-plant species that are currently not naturalized in Radolfzell but are likely to become so in the future. Although our approach cannot replace a full risk assessment, it is well-suited and applicable as one element of a screening or horizon scanning-type approach.     

Fleshy fruits of indigenous and adventive plants in the diet of birds in forest remnants, Nelson, New Zealand

The relationship between fleshy-fruited indigenous species and adventive weeds in the diet of 500 mist-netted birds was studied in forest remnants of differing size and degree of modification. Fruit abundance Peaked in March and April, and most fruit was either red/orange or purple/black. The physical parameters of adventive and indigenous fruits were not significantly different. Six of the 15 passerine species netted are frugivores, and of those netted 77% had eaten fruit. They were divisible into three groups: endemic (bellbirds, Anthornis melanura; tuis, Prosthemadera novaeseelandiae), non-endemic but indigenous (silvereyes, Zosterops lateralis), and adventive (blackbirds, Turdus merula; song thrushes, T. philomelos; starlings, Sturnus vulgaris). Bird diets varied between the groups and according to fruit availability as determined by sires and seasons. Endemic birds ate the least adventive fruit; bellbirds ate mainly Podocarpus hallii and Coprosma robusta fruits at all sites. Tuis had a varied diet, including some adventive fruits. Silvereyes ate the widest range of indigenous and adventive fruits. Blackbirds and, to a smaller extent, song thrushes ate many of the same indigenous fruits as the other bird groups, but their diet included more adventive fruits, e.g., Berberis glaucocarpa. Starlings were caught only when they fed on Sambucus nigra, but they also ate a few indigenous fruits. There was little seasonal variation in bird numbers caught. Adventive species extended the seasonal availability of fruits into winter, particularly in the forest remnant closest to a town, which had the highest proportion of adventive fruits. Several weed species distributed mainly by non-endemic and adventive birds are forming new secondary vegetation. Some have large fruit crops which generally offer little food for endemic birds. Where fruiting weeds pre-empt sites that may have been occupied by native species, they create an inferior habitat for endemic birds. However, the non-endemic and adventive birds also disperse indigenous fruits into early successional vegetation, and the importance of their seed rain for conservation of biodiversity will therefore depend on the site.     

Effects of exotic-native species relationship on naturalization and invasion of exotic plant species北大核心CSCD

Aims: Darwin's naturalization conundrum describes the paradox that the relationship of exotic species to native residents could either promote or hinder invasion success through opposing mechanisms: niche pre-adaptation or competitive interactions. Previous Darwin's naturalization studies have showed invasion success could vary at stages, sites, and spatial and phylogenetic scales. Our objective was to assess the effects of exotic-native species relationship on invasion process of exotic plant species in China, where related research is still lacking. Methods: Generalized linear mixed models were used to examine relationship between exotic-native species relationship and performance of exotic species at different spatial scale (provincial, municipal and community) and invasion stages (naturalization, dispersal and invasion). At community scale, we measured environmental factors of communities we investigated to control the effect of habitat heterogeneity among them. Important findings: At the provincial and municipal scales, exotic species closely related to native flora were more likely to be naturalized and distributed, which is more consistent with the expectation of the pre-adaptation hypothesis. On the community scale, the exotic-native species relationship was not related to establishment and abundance of exotic species in the community. The results suggested that exotic species did not strongly compete with their close native relatives in communities, but were better adapted to areas where their close relatives had lived. Considering their high potential of naturalization and invasion, special attention should be paid to those exotic species that closely related to the native flora in the management of invasive species. © Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

川西平原农田啮齿动物群落动态：年间变动和季节变动

为了研究农田啮齿动物群落的动态规律,用标志重捕的方法给出了川西平原农田的啮齿动物群落的物种数、结合种群密度、生物量、物种多样性的Shannon指数与Simpson指数等5个变量的时间序列资料,并分析了这些时间序列的年间变动和季节变动的特点。结果表明：（1）5个变量总是处于不断的变化之中,特别是年间交替升降十分明显;（2）群落的全部8个物种从未同时出现过,同一个月最多有5个物种,最少只有1个物种;（3）5个变量季节变动的幅度均较大并各具有1至3个不等的明显的峰值,而年间变动的幅度则相对较小;（4）5个变量的最大值均出现在夏季,最小值则出现在春季、夏季或冬季;（5）5个变量的季节性均不强;（6）优势种大足鼠（Rattus nitidus)的种群密度分别与群落结合种群密度、生物量的年间变动和季节变动均具有相似的变动规律;此外,优势种大足鼠的种群密度、生物量分别占群落结合种群密度、生物量的比例均较高,而且这两个比例季节变动的幅度都较大而年间变动则较为稳定。     

Estimating the invasion success of introduced plants

We present methods for estimating the base proportion of introduced alien species that will naturalize, and the distribution of time until naturalization occurs. The approach is Bayesian, incorporating prior estimates of the probability of naturalization and the time from introduction to naturalization. A worked example uses data on the introduction and time to recorded naturalization of woody perennials introduced to South Australia. Up until 2007, 188 of 2230 (8.4%) woody perennials listed in nursery catalogues between 1843 and 1985 were recorded as having naturalized. If prior information on naturalization rates from elsewhere is ignored, the available data suggest that the most likely proportion of introduced plants that will naturalize is large (0.93) though uncertain (95% CI 0.51–0.99), with the corresponding mean time to recorded naturalization being protracted (522 years) and similarly uncertain (95% CI 360–678 years). Alternatively, if informative prior estimates of both the naturalization probability and the time to recorded naturalization are incorporated, the most likely probability of naturalization is estimated to be 18.6% (95% CI 15.5–23.4%). For those plants that do naturalize, the most likely value for the mean time from importation to recorded naturalization is 149 years (95% CI 130–174 years). Our results illustrate the potentially long timescale of the naturalization process, and the challenges this presents for obtaining accurate estimates of naturalization parameters.     

Naturalization of <Emphasis Type="Italic">Fragaria</Emphasis> × <Emphasis Type="Italic">ananassa</Emphasis> Duch. in Western Siberia

The process of the Fragaria × ananassa naturalization in Western Siberia lasts approximately 80 years from the moment of the appearance of first garden strawberry cultivars at agricultural experimental stations in 1933. The species invasive status changed slightly for such a long period of time (from casual alien plants to naturalized plants), and it corresponds to colonophytes in regards to degree of naturalization. The ornitochory is one reason the F. × ananassa appears in natural phytocenoses. At present, the F. × ananassa naturalization occurs in two directions, including genetic transformations in long-living coenopopulations and the reinvasion of new ecotypes of the same species in natural phytocenoses. The high death of seedlings in naturalized F. × ananassa does not allow the species to actively occupy regeneration niches in natural phytocenoses, which precludes the invasive plant status for the F. × ananassa at this stage of the F. × ananassa naturalization in Western Siberia.     

Lost and found: Short-term dynamics of the flora on 100 small islands in the White Sea

The aim was to uncover factors that influence short-term (decade) flora dynamics and species richness of northern marine islets characterized by poor flora and weak anthropogenic pressure. The study used presence–absence data of vascular plant species on 100 small uprising islets of the Kandalaksha Gulf of White Sea (Northern Karelia, Russia). We investigated the influence of islands' attributes on species richness and rates of flora dynamics. Two island types were analyzed separately: younger, stone-like and older, islet-like (which generally are larger and have higher diversity of habitats). Sampled islands were studied via classical biogeographical per island approach and metapopulation per species approach. Stone-like islands had noticeably poorer flora with higher rates of immigration and extinction when compared to those of islet-like islands. The species number for islet-like islands correlated positively with number of habitats, abundance of different habitat types and island area. Species richness of stone-like islands correlated positively only with number of habitat types. Plant species associated with birds, crowberry thickets and coastal rocks were the most stable, and the species of disturbed habitats were significantly less stable. Floristic changes that have occurred have been caused by the massive establishment of new species rather than the extinction of pre-existing taxa. Thus, most of these islands are still in the colonization (assortative) stage. While we found no relationship between island area and species number for stone-like islands, this relationship was seen on islet-like islands.     

ADVENTIVE EMBRYOGENESIS IN CITRUS I. THE OCCURRENCE OF ADVENTIVE EMBRYOS WITHOUT POLLINATION OR FERTILIZATION

Anatomical studies of unfertilized undeveloped seeds from open- and control-pollinated fruits of ten facultative apomictic Citrus cultivars were carried out with the aid of light and epifluorescence microscopes. With or without pollination, adventive embryos autonomously developed at all positions in the nucellus in all cultivars. The adventive embryos initiated at the chalazal end of the nucellus were more vigorous than those initiated at the micropylar end. Because of the lack of endosperm and poor seed development, however, all adventive embryos within the unfertilized seeds terminated their development at the globular or early cotyledonary stages and were unable to germinate under natural conditions. The capability of unfertilized seeds to develop varied from species to species. Growth of the adventive embryos was dependent on nucellus size, but the growth rate of adventive embryos relative to nucellus size was different in different species. Neither pollination, fertilization nor subsequent zygote and endosperm development further stimulated adventive embryo initiation. Conversely, pollination and subsequent fertilization of other seeds in the same fruit slightly, but significantly, suppressed adventive embryo growth in the unfertilized seeds. These facts concerning adventive embryogenesis in unfertilized seeds indicate that neither pollination nor fertilization is essential for in vivo adventive embryogenesis and that normal endosperm is necessary for perfect development of adventive embryos initiated only in the micropylar half of the nucellus.