If a tree falls over in a forest but no-one sees it happen, does it matter? If an insect species (in that same hypothetical forest) goes extinct but science had never described it, will anyone notice it’s gone? If climate change means the dominant tree species in that forest is likely to be unable to cope in twenty years time, should we give up on the forest because the local managers can’t do anything about climate change? The answer to all these questions (like so many questions in conservation science) is ‘it depends’.
Framing threats to ecosystems
Prior scientific knowledge inspires ecological research, hypotheses and debate but it’s rarely used to explicitly formulate predictive models. Bayesian statistics provide a formal way to include informative priors and evaluate their influence on parameter estimates. In this study, Tara Martin and colleagues use case studies of the influence of overabundant deer on the abundance of bird species on the Gulf Island, San Juan and Haida Gwaii archipelagos of western North America. They demonstrate the utility of informative priors and Bayesian modelling to determine the consequences of overabundance.
Marine protected areas (MPAs) have become the cornerstone of many national and international strategies for halting the loss of marine biodiversity. Australia has made strong international commitments to increase its coverage of MPAs through the principles of systematic conservation planning and, in the last ten years, has rapidly expanded its MPA coverage using these principles.
Temperate woodlands in Australia have been disproportionately cleared following European settlement. Biodiversity decline in such systems may be reversed by restoring native vegetation on agricultural land. However, rebuilding functioning habitat will require an understanding of what determines the distribution of species in existing habitat.
Nature is in trouble. How do we (as in the general public) know this? Because conservation scientists and conservation managers are telling us that some of our best known (and loved) animals and plants are disappearing. The ranges of many species are contracting, some in spectacular fashion, and their population sizes are dwindling. For some species it’s believed these declines won’t lead to the loss of the species (for the foreseeable future) but for others it’s believed they are close to becoming extinct.
Thanks to climate change and land conversion, Mexico’s famous cloud forests are shrinking. By 2080 it’s expected they may be a splinter of their former glory. The forests provide habitat for a disproportionate amount of the country’s biodiversity (see the box: ‘Head in the clouds’) but the impacts of forest loss will be felt differently by different species. Understanding these differences will be important when forming conservation plans. How, for example, will a local bird cope as opposed to a frog or a mouse?
Tropical Montane Cloud Forests (TMCFs) are special places created by specific processes. They are found in the tropics, at mid-altitude on the windward slopes, where the clouds intersect with the mountains. The persistent cloud cover over the canopy of the forest maintains the high annual precipitation (500–1000 mm) and humidity. It also ameliorates intense sunlight, maintaining a mean temperature of 12–23°C.
Eucalypts are iconic trees in Australian landscapes, and given the variety of treed landscapes that are found across Australia, that’s an amazing thing to consider. There are around 800 species (eucalypt taxonomy is a moveable feast) of three genera, Eucalyptus, Corymbia and Angophora that together are known as eucalypts or gum trees, and these trees have dominance or co-dominance in most forest and woodland ecosystems in Australia. You’ll find them in rainforests, up mountains and across the arid zone.
Be careful when playing with fire. It’s a message politicians know too well and after recent catastrophic wildfires in different parts of Australia they want to be seen as actively responding to the threat. One of the common responses is to raise the level of prescribed burning but what are the benefits and costs of this strategy?
I cannot change; the courage to change the things I can; and wisdom to know the difference.” It’s a great piece of advice for any conservation manager struggling to deal with multiple threats with inadequate resources. However, in an age when our most important (and much loved) ecosystems are under growing pressure, we’d like to suggest that true wisdom lies not only in knowing the difference between the things we can and can’t change, but also understanding how these things interact.
Late last year the Australian Institute of Marine Science put out a rather scary report on the state of the Great Barrier Reef. It said the Reef has lost half its coral cover in the last 27 years! The loss was due to storm damage (48%), crown of thorns starfish (42%), and bleaching (10%).
Basically, the big storms are coming more frequently than the reef can absorb, higher water temperatures are causing widespread coral bleaching and rampaging swarms of crown of thorns starfish are eating up huge areas of coral.
Like many important ecosystems, seagrasses will be hit hard by climate change. Some of those impacts relate to rising sea level. New research by a multi-disciplinary team at the University of Queensland has found that local action that improves water quality, and specifically its clarity, might go some way to compensating for rising sea level.
Seagrasses are marine plants that live in shallow coastal seas. They provide us with a range of valuable ecological services including the provision of habitat for fish and invertebrates, and food for turtles and dugongs.
Biodiversity faces unprecedented challenges arising from habitat destruction and degradation, climate change and other stressors. Addressing these challenges compels conservation management decisions to be informed by science – the most comprehensive knowledge system in place to understand natural phenomena. But keeping up with today’s science is a challenge in itself, the body of ecological knowledge is growing faster than ever before. In practice, there are many obstacles to incorporating scientific evidence into decisions
“1978 was a good year; I wasn’t earning much but I felt happier.” That’s what your average global citizen might say after reading Kubiszewski et al. 2013. Standard economic indicators like gross domestic product (GDP) are useful for measuring just one limited aspect of the economy—marketed economic activity—but GDP has been mistakenly used as a broader measure of welfare. A more comprehensive indicator would consolidate economic, environmental, and social elements into a common framework to show net progress.
Dbytes is EDG’s internal eNewsletter. It gets sent to members and associates of EDG each week, and consists of small snippets of information relating to environmental decision making. They might be government documents, research articles, blogs or reports from other research groups. Here are five bytes from recent issues.