İç Anadolu bozkırındaki bitki çeşitliliği ve toprak örtüsünün Diplotaxis tenuifolıa (L.) DC.'nın fide yerleşimine etkisi

Invasive exotic plants increasingly pose a threat to native biodiversity in many parts of the world. However, they have rarely become successful in Turkey. One hypothesis suggests a highly diverse native flora avoids establishment of any potential invaders through intense competition. This hypothesis was tested through an experimental setup where a native plant, the Perennial Wall-rocket (Diplotaxis tenuifolia) was used to emulate an invasion at its early stages. D. tenuifolia is a cosmopolitan flowering plant native to parts of North Africa, West Asia and Europe, and considered to be invasive in regions such as Australia, Argentina and North America. The study took place at METU where ungrazed pockets of typical of Central Anatolian Steppe remain. The experimental setup involved varying levels of reduced species richness and/or ground cover through manipulation of the local vegetation, followed by transplanting the "invader" species and then recording its fate as a function of native plant diversity. Survival rates of D. tenuifolia seedlings were found to be significantly different, but showed weak effects for plots with varied levels of species richness and ground cover. At the end of the experiment, survival rates of D. tenuifolia seedlings in low, middle and high species richness categories was observed as %15.74, %18.83, and %16.36, respectively; and survival rates of low, middle and high cover categories was observed as %17.90, %20.68, and %12.34, respectively. This is the first study that explores conditions for invasiveness in Turkey. While this study does not confirm our main hypothesis, it paves the way for future research on explaining why invasive plant species are not successful in Turkey.