Today I had a number of journal related obligations (for the Journal of Applied Ecology -which is celebrating its 50th anniversary here at the conference) and I had time to attend just a few talks. I saw some great talks -especially by Tad Fukami on evolutionary priority effects, but I decided to only post my (inadequate) notes about two of the plenary talks today. They were great talks, and both of them really expanded my perception of human-caused effects on natural systems, in very different types of habitats.
Ove Hoegh-Guldberg. Corals reefs and global climate change. Coral reefs occupy less that one percent of ocean area but one in four fish caught come from reefs, supporting 400 million people. In the Caribbean coral cover has drastically declined from 80 percent cover to about 10 percent. This has happened elsewhere too, Asia and Australia. In Australia, where coral reefs are well protected and financed, they are still declining. Human development, pollution from agriculture and over harvesting are the common local causes, but global warming and ocean acidification are major global changes. Marine systems are greatly warming, more than land, but very few studies in marine systems. Increases in sea temperature can result in mass coral bleaching and death of corals. Major bleaching events over the past two decades, killing significant proportions of coral. Even though temperature is the best predictor of bleaching, mortality is more variable and other factors may help corals recovery, and these other factors are what managers can influence. In the coming decades, warming temperatures will mean common widespread bleaching events, with some areas becoming too warm for corals. Based on large mesocosms that track local ocean temperature and co2 concentrations. With warming, the mesocosm reefs change into algal dominated systems, with fewer other types of species (e.g., sea cucumbers). Two scenarios to deal with climate change -mitigate or adapt. We need to mitigate within twenty years, reduce co2 emissions. To get change we need reach more than the brain, but the human heart. Partnered with Google to have street view for reefs (this is completely awesome -check it out here). This initiative is both science (mapping reefs) and important outreach, letting people experience diving. One billion people have visited with almost two million people 'dived' in the first week.
Nancy Grimm. Water systems in urban habitats. Populations around the world are moving to cities, and projections have over 650 cities with over a million people by 2025. Creates multiple stressors in urban ecosystems, and there is a new need to build knowledge capacity. Large proportions of people already live in urban areas with limited water supply, quality and delivery capacity. Eighty percent of the population lives in areas under threat of water scarcity, but some people have access to technological solutions that minimize this (e.g., arid USA). For others, ecological knowledge may help reduce this threat. Areas around the world are experiencing more heavy rainfall and flooding. The way municipalities deal with storm water is building hard channels and surfaces, but building ecological systems can better handle water and pollution. In the arid southwest, there are opportunities to retain storm water in semi-natural systems. Provides ecosystem services and denitrification.
Sorry for the brevity of the talk summaries -I'm working on a very full schedule!