Whilst Island Biogeography Theory originally led many to believe that larger, more connected patches of habitat are more important for species conservation, new research suggests that overlooking smaller patches could be dangerous (Image Credit: LuxTonnerre, CC BY 2.0, Image Cropped)
Global synthesis of conservation studies reveals the importance of small habitat patches for biodiversity (2019) Wintle et al., PNAS, https://doi.org/10.1073/pnas.1813051115
Human land use over the past millenia has divided species habitats into smaller and smaller patches – a practice which often leaves conservationists with the tough choice of which remaining patches they should focus their efforts on. Traditional practice has seen the prioritisation of large patches that are well connected to other, with this preference often meaning that smaller more isolated patches are neglected, and often cleared.
This week’s paper authors wanted to check whether this was really the best way of doing things, by looking at the relative conservation value of a variety of habitat patches.
Whilst climate change continues to hog the limelight, habitat loss remains the key threat to biodiversity worldwide. And whilst events like the Australian bushfires obviously contribute to habitat loss, its main cause is land clearing, whether for agriculture, cattle grazing, mining or urbanization. No matter how many politicians deny or try to deviate attention from it, scientists have shown time and time again just how threatening habitat loss is to our planet’s biodiversity.
On the surface, the process seems quite simple. Habitat goes away, animals lose shelter and food. Yet this is just the tip of the iceberg. Many processes take place below the surface, cascading through an ecosystem. So let’s have a look at the manifold effects of habitat loss, and why it’s the greatest threat to biodiversity today.
The Amazon rainforest, which houses the largest area of intact forest landscape which lies within indigenous lands (Image Credit: David Evers, CC BY 2.0, Image Cropped)
Importance of Indigenous Peoples’ lands for the conservation of Intact Forest Landscapes (2020) Fa et al., Frontiers in Ecology and the Environment, https://doi.org/10.1002/fee.2148
Pristine forests remain not only a home for a huge range of biodiversity, they are also important resources for carbon storage, meaning their protection will become crucial as temperatures rise globally. Yet the term ‘pristine forest’ can be subjective. With this in mind, Peter Popatov et al., defined an IFL (Intact Forest Landscape) as a seamless mosaic of forest and associated treeless ecosystems that do not display obvious human activity or fragmentation. These areas are capable of housing entire species, including those that have expansive ranges.
The intent of this paper was to try and determine what proportion of that land intersects with land owned by Indigenous Peoples, to see how significant a role Indigenous Peoples could play in both conservation of biodiversity and the mitigation of climate change.
Image Credit: Joey Doll, CC BY 2.0, Image Cropped
Conservation or politics? Australia’s target to kill 2 million cats (2019) Doherty et al., Conservation Letters, https://doi.org/10.1111/conl.12633
We’ve talked a lot lately about competition between causes on Ecology for the Masses. Often when extra attention is given to one cause over another equally valid cause, it’s a product of social trends coinciding at the right time, sudden events capturing the public interest (think the Notre Dame fire) or a particularly effective marketing campaign. But sometimes a cause or a conservation target can be used to deliberately distract the public from another cause, and it’s a potential example of this that we’re looking at today.
Australia has long had an issue with cats. They’ve decimated populations of native species, playing a large hand in the extinction of many species found nowhere else. So it makes sense that part of Australia’s first Threatened Species Strategy would be to minimise the impact of cat populations on local wildlife. The strategy included a target of 2 million cats being killed between 2015 and 2020. Whilst this might sound like a reasonable goal, this paper argues that the actual scientific evidence supporting the target is pretty weak, and goes into some alternatives and motives.
Kiftsgate Court Garden: The Wild Garden 1. An example of a “wild garden” in the UK, where the plants have been left to grow (Image Credit: Michael Garlick, CC BY-SA 2.0, Image Cropped)
How do you make your garden more biodiversity-friendly? During my time at the Futurum exhibition at The Big Challenge Science Festival, I spent a lot of time talking to people who expressed a desire to be manage their gardens for more plants and animals, but were unsure where to start. So I’ve compiled a brief guide on what to do, and it’s your lucky day – it involves not doing anything.
Image Credit: Shannon McCauley, CC BY-SA 2.0, Image Cropped
Community ecology is one of the more recent ecological disciplines, and has enjoyed a rise in popularity in the last decade. Yet it’s often been criticised as a little obscure, and has had difficulties integrating with other branches of ecology like evolution and population dynamics.
With this in mind, I sat down with Doctor Shannon McCauley of the University of Toronto during her recent visit to the University of Arkansas. Shannon is a community ecologist at the University of Toronto-Mississauga who uses dragonflies and other aquatic insects to answer questions about dispersal, community connectivity, and the effects of climate change. We attempted to put a little more context behind community ecology, and highlighted its relevance in the coming years.
Sea otters are one of many charismatic species found along the California coast, yet recovery doesn’t seem to be helping them. Is it something about their habitat that is preventing population growth? (Image Credit: Mike Baird, CC BY 2.0, Image Cropped)
Gaps in kelp cover may threaten the recovery of California sea otters (2018) Nicholson et al., Ecography, DOI:10.1111/ecog.03561
In the 18th and 19th centuries, the fur trade was a massive industry in North America. As a result, many species were hunted and trapped to near extinction. The California sea otter (Enhydra lutris) was reduced in population to less than 50 total individuals. The enactment of the Internation Fur Treaty allowed the species (and others) to come back from the brink of extinction, and they now number over 3200 individuals and are spread across 525km of the California coast. Interestingly, although the population is recovering, it has not bounced back as quickly as other protected mammals living in the same habitat. The California sea lion, for example, has a maximum population growth rate more than twice that of the sea otter (11.7% compared to 5%).
Despite the remarkable recovery of the species, the sea otters occupy less than a quarter of their historic range and have not expanded along the coast in 20 years. The authors of this paper wanted to investigate what it is about the sea otters and their habitat that is slowing this population’s growth rate and spread along the coast.