Projects

Seed-based restoration to prevent the establishment and spread of invasive species

Megvalósítás alatt lévő/Futó projekt

Summary:

Invasion of alien species is one of the major drivers responsible for biodiversity decline and the resulting impacts on human economy and well-being. Certain plant traits, high propagule pressure and priority are possible explanations for the invasive success of alien species. These mechanisms are also proposed to affect the biotic resistance of native communities to alien invasion. The present study aims to test alternative hypotheses that explain the biotic resistance of native communities to invasive alien species based on trait similarity, propagule pressure and priority. We also aim to scientifically base the development of best practices of seed-based conservation and restoration to prevent the establishment or further spread of invasive alien species. The project includes i.) a synthetic assemblage experiment that includes all three mechanisms in parallel and that models recently abandoned degraded areas without vegetation cover, and ii.) a field experiment to control an already established invasive species that model real-world nature conservation efforts. Since the impact of the three mechanisms also depends on the identity of the invader, we include three widespread invasive species that represent different life forms and functional groups. Our results will open up a new perspective on the control and prevention of invasive spread that can form the scientific basis for the development of new, efficient sowing methods for nature conservation and restoration. The knowledge will also be transferred to local farmers and land managers to increase social usability and to MSc and PhD students as part of their research training.

Aims:
The present study aims to test alternative hypotheses that explain the biotic resistance of native communities to invasive alien species and to develop best practices of seed-based conservation and restoration to prevent the establishment or further spread of invasive species.
Our alternative hypotheses are:
1. Trait similarity: Based on the limiting similarity hypothesis, seeding of native species with similar traits to that of invasive species will increase biotic resistance.
2. Propagule pressure: Higher sowing density of native species increases their chances of establishment resulting in higher native plant density that creates biotic resistance.
3. Priority effect: Since early-arriving species can strongly influence those arriving later in a system, establishing native species before the emergence of invasive species will increase biotic resistance.
4. Combination of alternative mechanisms can further increase biotic resistance and maximum resistance can be achieved by the triple combination.
Our related questions are:
Can we induce ecosystems to become more resistant to plant invasion by manipulating trait similarity, the amount and the order of arrival of plant species?
Are invasive species less successful in (re)establishment and growth if seeded
a. with native species of similar traits?
b. with higher density of native species?
c. after native species?
Are invasive species the least successful in (re)establishment and growth if native species of similar traits are seeded at a higher rate and prior to invasive species?