GEOGRAPHICAL PRINCIPLES OF DISTRIBUTION OF INVASIVE FLORA OF RAILWAYS IN KIROVOHRAD REGION

Development of transport capable to overcome distances of the planetary level, was caused to more intensive, than early, expansion allied, especially invasive, species of plants that become concurrent for aboriginal flora. Phytoinvasions are one of the most important geoecological problems of our time, as they disrupt the species composition and structure of natural phytocenoses, ultimately leading to the impoverishment of the plant component of landscapes and the reduction of biodiversity. One of leading factors in the spread of adventitious and, in particular, invasive species is rail transport, as a result of which seeds and organs of plants capable of taking root and gradually displacing the aboriginal flora get in the way. Although among the invasive flora of Kirovohrad region there are representatives of different systematic groups and life forms of plants, still clearly dominated by angiosperms and - at the same time - herbaceous plants. Main peculiarities of the space differentiation are described by the examples of railway stations of Holovanivsk and Znamianka situated consequently in the West and the East of the Kirovohrad region. The most common representative of the invasive flora of the railways of the studied region is ragweed, also widespread grindelia spread (in the west of the Kirovograd region) and sweet silique (in the east of the region). Of the families of flowering plants, the most widely represented are Aster (Compositae), a significant place is occupied by Cabbage (Cruciferous), Thin-legged (Cereals), Legumes and others. Factors contributing to the naturalization of invasive species and their rapid displacement of aboriginal flora are various. The main ones are eurybiont, unpretentious to the conditions of the habitat, the significant size of the aboveground phytomass. The internal diversity in the invasive flora of the region's railways is mainly due to the influence of the factor of the sectoral nature of natural conditions within the territory rather elongated from west to east. Therefore, in the presence of clear common features characterizing the invasive flora of the region, the differences associated with predominance of moisture-loving plants in the western part of the region and drought-resistant plants in the eastern part are noticeable. The practical use of the study results is associated with the possibility of improving the system of measures to combat phytoinvasions, taking into account the geographical features of the spatial distribution of individual species. Results of the investigation may be used during realizing tasks of ecologization of land using, especially defining priorities in the struggle with invasive species of the plants of railways. Discovered internal differentiation in expansion different allied species in Kirovohrad region gives a ground for defining the most important factors of distortion natural biodiversity in its different parts. Studying space peculiarities of expansion allied flora has a significance for create concrete actions directed to renewing initial space composition of phytocenosis and landscapes distorted by invasions. Key words: invasive flora, railway tracks, Kirovohrad region, adventitia, ragweed, grindelia spread, itching eastern.

Main directions of the study of plant invasions in Russia

This article is focused on the analysis of major approaches to plant invasion research used by Russian researchers. They fall within three main groups: 1. Conventional approaches to floristic analysis based on the Russian scientific tradition of floristic research, 2. Approaches focused on the study of the fraction of invasive flora, making blacklists and regional Black books, 3. New comprehensive approaches based on a synthesis of methods used in botany, geo-information technology and population genetics. Multivariate statistical methods allow for the visualization of various data, including those on alien species group structures in various regions. They make it possible to identify boundaries of ecological niches occupied by plants in respect to climate-and-environmental or ecological variables. An assessment of current statistical interdependence between alien plant characteristics and scores of factors limiting their dissemination facilitates the making of predictive models of plant invasion. Examples of multivariate statistical methods used in invasion biology were analyzed, along with different approaches to the study of the variability of alien species. Alien and invasive fractions of the flora of the Trans-Siberian Railway were analyzed not by administrative units but by natural biomes. This approach allowed us to assess the correlation between the number of invasive species with different natural-climatic and floristic characteristics of biomes. The publication of "Black Books" of various administrative subjects of Russia according to a unified methodology allowed us to make an inventory of invasive species over the vast territory of the country. The experience gained by Russian researchers may be further used for developing universal approaches to plant invasion research.

Influence of invasive flora species on the ecosystem of the Russian Far East

For the first time, based on the revision of herbarium collections, the resettlement of alien flora faction species in the Far Eastern Federal District (FEFD) was divided into four stages. Of the 117 invasive species of the Far Eastern Federal District, 47 ones were registered for the first time before the construction of the Trans Siberian railway, i.e. at the turn of the 1900s, 30 - from 1900 to World War II, 29 - from 1940 to 1980, i.e. before the targeted study of the alien flora faction, and 11 - from 1980 to the present. The data on scientists who played a key role in the study of the flora of the Far Eastern Federal District is presented. Seven species are only beginning to invade natural plant communities, 88 species are actively invading natural plant communities and 22 species belong to the “transformers”, which actively invade themselves into natural and seminatural communities, change the physiognomy of ecosystems, disrupt succession links, forming large single-species dense stands and force out and (or) obstruct the reproduction of aborigine species.

Fire Can Reduce Thorn Damage by the Invasive Callery Pear Tree

Callery pear (Pyrus calleryana) is an invasive tree across much of the eastern United States that can form dense thickets, and tree branches and stems are often covered in sharp thorns. Landowners and land managers attempting to manage callery pear infestations are faced with the challenge of killing and/or removing the trees while also avoiding thorn damage to equipment, which can lead to wasted time and increased costs. We evaluated fire as management tool to reduce the likelihood of equipment damage from callery pear thorns. Branches were collected in the field from callery pear trees that were killed by herbicide, and also from untreated trees, and half the branches from each group were then burned with a propane garden torch to simulate a low-intensity prescribed fire. After treatment, all branches were returned either to an old field or forest floor for 1 year, after which thorn puncture strength was evaluated and compared with freshly cut thorns. Herbicide treatment and location did not affect thorn strength, but burning reduced the likelihood that thorns would puncture a tire. Fire increased tip width, which reduced thorn sharpness. Burning also reduced wood strength, and fungi proliferated on burned thorns after 1 year in the field or forest. Both factors likely contributed to decreasing thorn strength and probability of puncture. Our results show that using prescribed fire as a management tool can weaken callery pear thorns and dull their tips, reducing the chance of equipment damage and costs associated with clearing land of this invasive species. Leaving cut callery pear trees on the ground for 1 year increased fungal colonization, which may also reduce thorn damage. Prescribed fire can be part of an effective integrated management plan for this, and possibly other, thorny invasive flora.

A weed risk analytical screen to assist in the prioritisation of an invasive flora for containment

Prioritising weeds for control and deciding upon the type of control and its associated investment are fundamental to weed management planning. Risk analysis is central to this process, combining the activities of risk assessment, risk management and risk communication. Risk assessment methodology has a rich history, but management feasibility has typically been a secondary matter, dealt with separately or not at all. Determinants of management feasibility for weeds include the stage of invasion, weed biology, means of control and cost of weed control. Here, we describe a simple weed risk analytical screen that combines risk assessment with species traits that influence management feasibility. We consider stage of invasion, species biological/dispersal characteristics and plant community invasibility in a preliminary analysis of the risk posed by the non-native plant species on Christmas Island in the Indian Ocean. For each of 31 high-risk species considered to be ineradicable under existing funding constraints, we analyse the risk posed to two major plant communities: evergreen closed-canopy rainforest and semi-deciduous scrub forest. Weed risk ratings are combined with ratings for species-intrinsic feasibility of containment (based on a measure that combines time to reproduction with potential for long distance dispersal) to create preliminary rankings for containment specific to each community. These rankings will provide a key input for a more thorough analysis of containment feasibility – one that considers spatial distributions/landscape features, management aspects and the social environment. We propose a general non-symmetric relationship between weed risk and management feasibility, considering risk to be the dominant component of risk analysis. Therefore, in this analysis species are ranked according to their intrinsic containment feasibility within similar levels of risk to produce an initial prioritisation list for containment. Shade-tolerant weeds are of particular concern for the closed-canopy evergreen rainforest on Christmas Island, but a greater diversity of weeds is likely to invade the semi-deciduous scrub forest because of higher light availability. Nevertheless, future invasion of both communities will likely be conditioned by disturbance, both natural and anthropogenic. The plant communities of Christmas Island have undergone significant fragmentation because of clearing for phosphate mining and other purposes. With a substantial number of invasive plant species firmly established and having the potential to spread further, minimising future anthropogenic disturbance is paramount to reducing community invasibility and therefore conserving the island’s unique biodiversity.

EXOTIC INVASIVE FLORA EVALUATION ON DIFFERENT ENVIRONMENTS AND PRESERVATION CONDITIONS FROM AN AREA BELONGING TO CAATINGA, PETROLINA, PE

Biological invasions are increasingly common worldwide due to continuous transformations that environments have been undergoing. Thus, this study aimed to catalog the exotic invasive species that occur on different environments at the Agricultural Sciences Campus from the Federal University of the São Francisco Valley, Petrolina-PE and to measure the distribution of the species diversity in the evaluated environments. The study area was initially divided into six environments. By walking around (active search) through these environments, all exotic invasive species were collected and herborized. Overall, 29 species were sampled, distributed into 16 genera and 12 families. From all catalogued species, 18 were herbs, four trees, four climbing plants and three were bushes. Regarding their origin, 13 were from African continent, one from Europe, two from Asia, two from India, one from Madagascar and four from Central America. Some species still have natural occurrence at more than one continent. The ruderal environments showed greater similarity to each other, with a percentage of exotic invasive species in common, equal or greater than 75%. This study suggests that modified (degraded) environments are enabler of biological invasions.