Abstracts

To develop the following abstracts, the editorial staff searches more than 100 scientific journals, professional and organizational newsletters, conference proceedings, and other resources for information relevant to ecological restoration practice and research. Please send suggested abstract sources to the editorial staff (ERjournal@aesop.rutgers.edu).

Climate Change

Climate Change-Induced Water Stress Suppresses the Regeneration of the Critically Endangered Forest Tree Nyssa yunnanensis. 2017. Zhang S., H. Kang and W. Yang (Yunnan Academy of Forestry, Kunming, Yunnan Province, China, wzyang2004@126.com) PLOS ONE 12. doi: 10.1371/journal.pone.0182012

Drought induced by climate change has significantly impacted forest regeneration worldwide and both drought frequency and intensity is increasing. Seedlings are particularly vulnerable to drought-induced mortality which can cause significant recruitment bottlenecks and reduce forest regeneration. Nyssa yunanensis is a critically endangered tree with extremely small populations in Yunnan province, China. Although this tree produces abundant seeds, establishment is typically very low. Zhang et al. examined the barriers to regeneration in field and lab experiments to determine which factors inhibit germination and establishment. In the field, low soil water potentials significantly reduced seedling survival and lab experiments further supported this result. Nyssa yunnanensis demonstrates autotoxicity and drought conditions increased concentration of soil toxins, causing additive effects that further decreased seedling survival. The authors also searched climate records and found declines in both rainfall (21.7%) and humidity (6.3%) over 55 years, indicating that N. yunnanensis populations are suffering from climate change-induced drought. Restoration plans for N. yunnanensis must include drought mitigation to ensure success.

Coastal & Marine Communities

Testing for Thresholds of Ecosystem Collapse in Seagrass Meadows. 2017. Connell, S.D. (Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, North Terrace, The University of Adelaide, South Australia, Australia, sean. connell@adelaide.edu.au), M. Fernandes, O.W. Burnell, Z.A. Doubleday, K.J. Griffin, A.D. Irving, J.Y.S. Leung, S. Owen, B.D. Russell and L.J. Falkenberg. Conservation Biology 31:1196–1201. doi: 10.1111/cobi.12951

Some ecological systems are susceptible to abrupt changes after seemingly small environmental perturbations. In such cases, it is important to be able to identify stressors in order to prevent the system from reaching the threshold at which community shifts happen. Seagrass meadows provide a number of ecosystem services and coastal eutrophication has been identified as a main cause of their disappearance. However, the point at which eutrophication causes a sudden loss (i.e., threshold effect) or whether eutrophication results in a more gradual reduction of seagrass biomass is yet to be determined. Connell et al. subjected patches of the seagrass Amphibolis antarctica to different levels of nutrient enrichment and found that A. antarctica does exhibit a specific threshold response to eutrophication. Epiphyte load increased with increasing nutrient load, however small increments in nutrient loading had no effect on leaf turnover. The high-nutrient treatments showed a significant decrease in leaf turnover, evidencing non-linear dynamics and an unforeseen tipping point. The information gathered here is of great value to avoid these effects in managed seagrass meadows and for the restoration of areas that have already crossed the threshold.

Behavioural Changes of Atlantic Cod (Gadus morhua) After Marine Boulder Reef Restoration: Implications for Coastal Habitat Management and Natura 2000 Areas. 2017. Kristensen L.D. (The Danish AgriFish Agency, Ministry of Environment and Food of Denmark, LODAKR@lfst.dk), J.G. Støttrup, J.C. Svendsen, C. Stenberg, O.K. Højbjerg Hansen and P. Grønkjær. Fisheries Management and Ecology 24:353–360. doi: 10.1111/fme.12235

Habitat complexity reduction resulting from the destruction of hard-bottom habitats is a well-known side effect of trawl fisheries. In benthic communities, the negative effects of marine substrate extraction for building coastal structures are even greater as the habitat cannot recover its original complexity naturally. Even after recolonization, the new community most likely will differ from the original because the topography has not been restored. In Kattegat, between Denmark and Sweden, Atlantic cod populations have been reduced by overfishing and habitat loss due to substrate extraction, but boulder restoration projects are underway. Kristensen et al. analyzed behavioral changes of cod...