Combining biogeographical approaches to advance invasion ecology and methodology

Understanding the causes of plant invasions requires that parallel field studies are conducted in the native and introduced ranges to elucidate how biogeographical shifts alter the individual performance, population success and community-level impacts of invading plants. Three primary methods deployed in in situ biogeographical studies are directed surveys, where researchers seek out populations of target species, randomized surveys and field experiments. Despite the importance of these approaches for advancing biogeographical research, their relative merits have not been evaluated. We concurrently deployed directed surveys, randomized surveys and in situ field experiments for studying six grassland plant species in the native and introduced ranges. Metrics included plant size, fecundity, recruitment, abundance and invader impact, as well as soil properties and root associations with putative fungal mutualists and pathogens. Consistent with key invasion hypotheses, Bromus tectorum experienced increased size and fecundity in the introduced range linked to population increases and significant invader impacts, along with altered fungal associations. However, performance differences did not predict population increases and invader impacts across species. A notable finding was that disturbance facilitated greater recruitment in the introduced range for most species, thereby playing a crucial, though underappreciated, role in driving invader success. Directed surveys consistently generated information on plant performance and fungal associations. However, soil sampling suggested that directed surveys may have been biased towards disturbed conditions for half the species. Randomized surveys generated robust data for population comparisons and impact, but generally failed to produce performance metrics for species that were uncommon or flowered outside the peak sampling window. Field experiments controlled for bias and confounding factors and provided rare information on recruitment and disturbance effects, but poor recruitment in the native range and ethical constraints on growing invaders in the introduced range hindered comparisons of performance and plant–fungal interactions. Synthesis. Each method had strengths and weaknesses. However, when combined they provided complementary information to paint the most complete biogeographical picture to date for several introduced plants. We propose a hybrid approach to optimize biogeographical studies.Fil: Pearson, Dean. University of Montana; Estados Unidos. United States Forest Service. Rocky Mountain Research Station; ArgentinaFil: Eren, Ozkan. Adnan Menderes Universitesi; TurquíaFil: Ortega, Yvette K.. United States Forest Service. Rocky Mountain Research Station; ArgentinaFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Karakuş, Birsen. Adnan Menderes Universitesi; TurquíaFil: Kala, Sascha. University of Montana; Estados UnidosFil: Bullington, Lorinda. Mpg Ranch; Estados UnidosFil: Lekberg, Ylva. University of Montana; Estados Unidos. Mpg Ranch; Estados Unido

Determination of some of factors which affect invasive success of Poa bulbosa L., Bromus tectorum L., Potentilla recta L., Carduus nutans L., Rumex acetosella L. and Hypericum perforatum L. species

Ülkemizde ve dünyada istilacı bitkilerin önemli ölçüde tarımda ürün kayıplarına neden olduğu bilinmektedir. İstilacı bitkilerin neden olduğu verim kaybı ve onlarla mücadele etmek için kullanılan bitki koruma ürünleri kaynaklı ekonomik kayıplar çok ciddi boyutlardadır. İstilacı bitkilerin ekonomi ve ekosistemler üzerine olumsuz etkileri nedeniyle bu bitkiler üzerine çok sayıda çalışma yapılmaktadır. Bu araştırmalar çoğunlukla yabancı otların istila potansiyellerinin belirlenmesi, istila başarılarının altında yatan mekanizmaların ve alternatif kontrol yöntemlerinin belirlenmesi üzerine yoğunlaşmıştır. Bu süreçlerin anlaşılması bazı bitkilerin istila kapasitelerinin önceden tahmin edilmesine ve onlara karşı tarım alanlarında ve meralarda daha etkili kontrol stratejilerinin geliştirilmesine yardımcı olabilir. Bu nedenle bu çalışmada anavatanı ülkemiz olan 6 istilacı bitki türünün (Poa bulbosa, Bromus tectorum, Potentilla recta, Carduus nutans, Rumex acetosella ve Hypericum perforatum) çok yıllık otlaklardaki istila başarıları ve fenotipik varyasyonları Türkiye de çalışılmış, elde edilen bulgular bu türlerin egzotik olduğu Montana'dan (USA) elde edilen başka bir çalışmanın bulgularıyla karşılaştırılmıştır. Sonuçlarımız her türün birbirinden bağımsız istila başarısına sahip olduklarını göstermiştir. Başarılı istilacılardan B. tectorum Montana'da daha fazla biyomas ve tohum üretirken, H. perforatum ve P. recta anavatanı olan Türkiye'de daha yüksek gelişim göstermiştir. Carduus nutans her iki ülkede benzer bolluk gösterse de Montana'da daha yüksek biyomas ve daha fazla canlı tohum ürettiği tespit edilmiştir. Poa bulbosa iki ülkede biyomas da herhangi bir farklılık göstermese de Montana'da daha fazla tohum ürettiği, Rumex acetocella'nın ise istila başarısında iki bölge de herhangi bir farklılık göstermediği saptanmıştır.In the world and in our country, invasive plants are known to cause significant loss of products in agriculture. The yield loses caused by invasive plants as well as the plant protection products used to control those lead to very serious economic losses. Because of their negative impacts on economy and ecosystems, many studies have been conducted on invasive plants. These studies are mostly concentrated on to determine the invasive potential of those species, the mechanisms underlying invasion success and the development of alternative pest control methods. Determining the differences in phenotypic traits between populations may help to understand why some weeds reach higher abundance in certain regions. Understanding these processes will facilitate the estimation of the invasion capacity of the plants and will help to develop more effective control strategies in agricultural areas. For this reason, in this study fenotipic variation and invasive sucsess of 6 invasive species (Poa bulbosa, Bromus tectorum, Potentilla recta, Carduus nutans, Rumex acetosella ve Hypericum perforatum) native to Turkey has been studied in perennial grasslands of Turkey. Resuls obatined from this study have been compared another studies conducted on those species in Montana (USA). Our results showed that each species, independent of invasive success, had different results. Of the successfully invasive species, B. tectorum grew larger and produced more seeds in Montana, while H. perforatum and P. recta grew larger in Turkey. Conversely, C. nutans, a species that may have a similar abundance in both ranges, grew larger and produced more viable seeds in Montana. P. bulbosa showed no difference in shoot biomass but produced more seeds in Montana, and R. acetosella showed no overall differences

Are problem invaders bigger and more fecund in the introduced versus native range?

Plant invasions have detrimental effects on ecosystem structure and function, and are expensive to manage. Roughly one in ten exotic plants becomes invasive, but the underlying mechanisms that contribute to invasiveness are not well known. In an effort to better understand the relationship between plant size and fecundity and invasive success, we compared growth and reproduction of six plant species in their native (Turkey) and exotic (Montana, USA) ranges. Three species were chosen (Bromus tectorum, Hypericum perforatum, Potentilla recta) that represent high-impact invaders recognized as noxious weeds in Montana, while the other three (Carduus nutans, Poa bulbosa, and Rumex acetosella) were chosen because they are not recognized as problematic species in the area. Replicate populations for each species were collected in each range for analysis of biomass and seed production. We predicted based on EICA that successful invaders would be bigger and produce more seeds in the introduced range relative exotic plants that fail to invade. Of the problem invaders, B. tectorum grew larger and produced more seeds in Montana, while H. perforatum and P. recta grew larger in Turkey. Conversely, of the species that are not problematic in the introduced range, C. nutans grew larger and produced more viable seeds in Montana, P. bulbosa did not differ in size but produced more seeds in Montana, and R. acetosella showed no difference in biomass or seed production. For our six species, we found no consistent relationship between invader impact and plant size or fecundity between ranges