Restoration: The Ultimate Test

1. Restoration: The Ultimate Test By :Nicole Kroutter Rob Harvey Nikki Thurgate

2. Restoration: A Win - Win Situation In his article, John Ewel proposes that ecosystem restoration is an activity at which everyone wins When successful, a disrupted fragment of the Earth�s surface is returned to its undisturbed state. When plagued with failure, the information learned about the environment becomes a powerful tool for future success.

3. Ewel�s Five Point Criteria Sustainability Invasibility Productivity Nutrient Retention Biotic interactions

4. Sustainability Sustainability is the ability of the newly reconstructed environment to perpetuate itself without constant management. Proper planning can increase the chances of a new system becoming independent. Sustainable development has become an important issue for restoration ecologists

5. Sustainability Models Dr. Sylvia Earl, in conjunction with National Geographic has proposed a model for a Sustainable Seas program. Her program, like others, devotes itself to the human -side of sustainable development

6. Invasibility To fulfill this criteria, a reconstructed community must be capable of resisting invasion by new species. Intact communities are more resistant to invaders than those that have suffered from disruption Invasion by non-indigenous species are now recognized as one of the leading threats to biodiversity and ecosystem function.

7. Tracking the Enemy Invasive plants alter ecological processes, displace desirable species, and reduce wildlife habitat quality. Invasive species usually entered disturbed areas and fill in newly formed niches. Ecologists are devoting a great deal of study into what makes a species an invader and why some communities are resistant to invasion.

8. Predicting Invaders Invasive species have a variety of characteristics that increase their fitness. In plants these include:a history of invasion, an uneven phylogenetic distribution, and vegetative reproduction.

9. Establishment as an Invader Species entrained in transport path Species survives transport and introduction Species becomes established in the new geographic area Species spreads from the point of introduction Species becomes abundant, and begins to fill in niches while adversely effecting the native population.

10. Productivity Productivity depends upon the efficient use of resources by the restored community. Ideally, the newly restored community will become as productive as the original. Productivity can be measured on several levels

11. Measurements of Productivity Primary production Secondary production Gross productivity Net productivity Net productivity is especially useful because it incorporates critical live processes such as respiration and photosynthesis.

12. Productivity Improving productivity of the soil can have a powerful impact on the overall health of a restored or damaged community Tropical shifting cultivation systems that employ fallow periods have shown an increase in overall soil productivity. The increase in productivity increases the system resistance to invasive species especially weeds

13. Nutrient Retention A reconstructed community must be able to maintain a steady level of critical nutrients. If the community can not control the rate of nutrient loss or gain of certain nutrients, the restored community will suffer. Either extreme of nutrient balance will result in a decrease in productivity, sustainability, and lead to invasion by other species

14. Nutrient Retention in Action Two of the most critical nutrients are Carbon and Nitrogen. Good retention of these nutrients increases the chance of recovery for a disturbed area

15. Additional Benefits of Nutrient Retention Nutrient Retention is not only necessary for plant survival, but offers many benefits to the ecosystem. One experiment focused on the effects of macrophyte species richness on wetland function. The increase in macrophyte diversity helped the wetland to retain additional amounts of Phosphorus, an environmental pollutant

16. Biotic Interactions The successful establishment of biotic interactions may be one of the most important steps in the restoration process. For many restored areas the reassembly of the plant population is enough to trigger colonization by various animal species. The interactions of a few key species, though, may determine the ultimate success of the community

17. Biotic interactions and Key Species Key species are those species that have a large impact on a community. Key species can be seen as �ecosystem engineers.� If key species are removed or do not returned to a restored area, large changes in ecosystem function will result

18. The influence of Biotic Interactions Experiments on species co-existence in temperate forests have offered some valuable insight into the role of biotic interactions. Biotic interactions are incredible important in the time frame from reproduction to establishment of a seedling These interactions include the role of pollinators and other critical species

19. Valuable Biotic Interactions Birds play a major role in seed dispersal Mycorrhizal interactions can provide the seedling with various nutrients Different species of tree have different advantages at different stages

20. Ewel�s Criteria in Action Case Study 1 Restoring Enriched Grassland: Effects of Mowing on Species Resistance, Productivity, and Nutrient Retention By John Maron Case Study 2 Dispersal Limitation, Invasion Resistance, and the Structure of Pond Zooplankton Communities By Jonathan Shurin

21. Case Study One In this experiment, scientists examined the effects of nitrogen enrichment on species- rich grasslands. Nitrogen enrichment has become an increasing problem due to the build up of nitrogen oxides in the atmosphere and soil The areas of nitrogen enrichment are prone to invasion by exotic species, increases in biomass, and loss of species diversity.

22. Case Study One The scientists hypothesized that removal of biomass through repeated mowing of the research area would lead to a drop in Nitrogen levels. Also it was hypothesized that the mowing would increase native species diversity, through the removal of nitrogen- fixing invaders such as bush lupine.

24. Results of Case Study One Mowing and the removal of biomass resulted in a dramatic change in species assembly The population shifted from exotic species to a mixture of exotic and native forbs community. Due to biomass removal and the shift in species, there were changes in nitrogen retention

25. Results of Case Study One The mowing ,though useful in increasing species diversity and productivity, did not succeed in reducing Nitrogen levels. In fact, the switch to the combination of exotic and native forbs due to mowing, actually resulted in increased nitrogen retention.

26. Case Study Two This experiment highlights the invasion resistance capabilities of a pond community The scientist introduced a sample of non-native zooplankton in several fishless ponds

27. Case Study Two In cases were native species diversity was high, the introduced invaders could not establish a foothold in the community. In fact, the success rate of introduction was low with many of the invaders becoming extinct. For those that became established, they had no impact on the overall community, since their total numbers were very low.

28. Results of Case Study Two The pattern established in this experiment supports the hypothesis that an increase in species diversity confers invasion resistance. The increase in biotic interactions among the natives also reduced the chance of invasion The same experiment conducted a test on the effects of introduced invaders on a community with limited diversity. In this test, the invaders did become established in the community.

29. Final Thoughts Both experiments illustrated the importance of nutrient retention, biotic interactions, invasibility, and productivity on the construction of a sustainable community. While one experiment failed to achieve its main goal and the other succeed, the overall knowledge of the interactions in a community was increased, making the efforts part of a win-win situation