Apophytes as invasive plants in the vegetation of Poland
Apophytes are native synanthropic plants, i.e. those found in disturbed habitats. Some apophytes with a limited geographic range, which are native to one part of a country, migrate out of their natural communities as "invasive" plants. We selected from the group of apophytes in Poland (more than 220 species) examples of such plants, which after World War II colonized new areas and often new habitats. They include, for instance, coastal species of dunes and salt marshes, or plants used as ornamentals. Moreover, some species of fresh meadows in the south of Poland, are now found in the north in ruderal habitats. The speed of colonization is high, such that in the last 20 years, starting from a few locations, some have taken over almost the entire area of Poland. The expansion of apophytes can be much faster than that of anthropophytes because apophytes have a higher number of diaspores or a shorter period of adaptation in new localities.
Directional northern element in the flora of vascular plants of Poland
The directional element is a local determinant of spatial diversity of flora of a given country, within widely understood geographical elements. In Poland, a country situated in the middle of Europe, most species belong to the transitional element (with no range limit in our country). Besides the transitional element, the directional northern element (with its southern limit in Poland) is present. It can be divided into two distinct groups: species that have their absolute southern range limit in Poland and those that have both southern and northern limits with a significant disjunction in Central Poland. Although they are two different groups, they will be discussed within the combined study. The first one constitutes 1.9% of the directional element, the second one 1.3%. As far as general ranges are concerned, Circumboreal and Eurosiberian species prevail in the first group, with a significant share of the taxa of geographical connective element. European-temperate taxa are the most numerous in the second group. The two above-mentioned groups will also be distinguished by their species belonging to the higher syntaxonomical units. Such a small share of the northern element in the flora of Poland confirms that our country belongs to the Central European Province, where the North-European element is, to a large extent, a relict of the earlier periods of the Holocene.
Adam Zając, Barbara Tokarska-Guzik and Maria Zając
The role of rivers and streams in the migration of alien plants into the Polish Carpathians
The Carpathians are among the regions of Poland that are generally less susceptible to invasive alien plants. The factor limiting the spread of the species of this group is, above all, the mountain climate. Even species originating from other mountain regions, e.g. the Himalayan Impatiens glandulifera, have their localities only at low elevations, in the Carpathian foothills. In most cases, alien plant species migrate into the Carpathians from the lowlands. The river valleys provide the migration corridors used by alien species in the course of their progress into new territories of the upper mountain localities. The situation along some mountain rivers, where invasive alien species dominate the native vegetation, is dramatic. Their spread is facilitated not only by easy diaspore transport but also by some anthropogenic factors, such as, river engineering and the transformation of riparian habitats and progressing devastation. Currently, we can observe some invasive alien plants "in statu nascendi", developing a new, secondary range in the Carpathians (e.g. Chaerophyllum aureum) or at the foothills, along the Wisła (Vistula) and San river valleys (e.g. Eragrostis albensis). For some species, cities were the destination for the first stage of future migration, e.g. Acer negundo. In the Carpathians, where many national parks and nature reserves are located, the continuous monitoring of the spread of invasive alien plants should be one of the principal activities of botanists.
The Polish Carpathians and their northern foreland are a rewarding object for the kenophyte distribution research. The study, using the cartogram method, showed that the number of kenophyte species decreases with increasing altitude. Only few kenophytes were found in the lower forest zone. This regularity concerns also the species that reach higher altitudes in the mountains of their native lands. A number of species migrated into the Carpathians through rivers and streams. River valleys generate many open habitats, which are easily colonized by kenophytes due to the lack of competition. In the Carpathians, towns used to be founded in the mountain valleys and this was also a favouring factor of kenophyte propagation. The arrangement of mountain ranges in the Polish Carpathians, including their foreland, hindered the migration of some species and allowed to discover the possible migration routes into the area covered by research. Tracing these migration routes was possible only for those species that have not occupied the whole available area yet. Additionally, the study indicated the most dangerous invasive species in the Polish Carpathians and their foreland.
These considerations have been based on the updated list of archaeophytes appearing in Poland. The extent of endangerment has been assessed for particular species according to the updated IUCN classification. Non-threatened and invasive species have also been taken into consideration. A number of quite fundamental changes have been made to the classification, as compared to the publication of Zając et al. of 2009.
Artur Gołaś, Adam Maszczyk, Adam Zajac, Kazimierz Mikołajec and Petr Stastny
Post activation potentiation (PAP) has shown improved performance during movements requiring large muscular power output following contractions under near maximal load conditions. PAP can be described as an acute enhancement of performance or an enhancement of factors determining an explosive sports activity following a preload stimulus. In practice, PAP has been achieved by complex training, which involves a combination of a heavy loaded exercise followed by a biomechanically similar explosive activity, best if specific for a particular sport discipline. The main objective of this study was to investigate the effects of PAP on performance in explosive motor activities specific for basketball, luge and athletics throws. The novel approach to the experiments included individualized recovery time (IRT) between the conditioning exercise and the explosive activity. Additionally, the research groups were homogenous and included only competitive athletes of similar age and training experience. Thirty one well trained athletes from 3 different sport disciplines participated in the study. All athletes performed a heavy loaded conditioning activity (80-130%1RM) followed by a biomechanically similar explosive exercise, during which power (W) or the rate of power development (W/s/kg) was evaluated. The results of our experiment confirmed the effectiveness of PAP with well-trained athlets during explosive motor activities such as jumping, throwing and pushing. Additionally, our research showed that eccentric supramaximal intensities (130% 1RM) can be effective in eliciting PAP in strength trained athletes. Our experiments also showed that the IRT should be individualized because athletes differ in the strength level, training experience and muscle fiber structure. In the three experiments conducted with basketball players, track and field athletes and luge athletes, the optimal IRT equaled 6 min. This justifies the need to individualize the volume and intensity of the CA, and especially the IRT, between the CA and the explosive activity.
Adam Zając, Małgorzata Chalimoniuk, Artur Gołaś, Józef Lngfort and Adam Maszczyk
Resistance exercise is a popular form of conditioning for numerous sport disciplines, and recently different modes of strength training are being evaluated for health benefits. Resistance exercise differs significantly in nature, and several variables determine the direction and range of adaptive changes that occur in the muscular and skeletal system of the body. Some modes of resistance training can also be effective in stimulating the cardiovascular system. These variables include exercise selection (general, specific, single or multi joint, dynamic, explosive), type of resistance (free weights, variable resistance, isokinetics), order of exercise (upper and lower body or push and pull exercises), and most of all the training load which includes intensity expressed as % of 1RM, number of repetitions, number of sets and the rest interval between sets. Manipulating these variables allows for specific adaptive changes which may include gains in muscle mass, muscle strength or muscle endurance. It has been well established that during resistance exercise fatigue occurs, regardless of the volume and intensity of work applied. The peripheral mechanisms of fatigue have been studied and explained in more detail than those related to the CNS. This review is an attempt to bring together the latest knowledge regarding fatigue, both peripheral and central, during resistance exercise. The authors of this review concentrated on physiological and biochemical mechanisms underlying fatigue in exercises performed with maximal intensity, as well as those performed to exhaustion with numerous repetitions and submaximal load.