Image Credit: Alexandre Roux, CC BY-NC-SA 2.0, Image Cropped
First interview. What does the term “invasive species” mean to you?
Obviously I expected some combination of “alien to the region”, “brandishes halberds and horned helmets” and “outcompetes the native trout” (trout and its fellow salmonids are really quite popular here). What I got instead (abridged) was a contemplative shrug and a reminder that there are almost no native populations of trout left anywhere in Norway.
Insert confused ecologist.
Urban aliens and threatened near-naturals: Land-cover affects the species richness of alien- and threatened species in an urban- rural setting (2020), Petersen et al., Scientific Reports, https://doi.org/10.1038/s41598-020-65459-2
Land-use changes (in particular, urbanisation and everything related to it) have huge effects on biodiversity patterns – some habitats can support populations of many different species, others cannot. This seems intuitive on a large scale (think a rainforest vs. a large, industrialised city) and on a small scale (a small patch of concrete vs. a patch of soil in a forest), but what about on a medium scale, more relevant to management organisations? How different species of plants, animals and fungi are distributed in space on such a meso-scale is far more relevant to everyday management, compared to say a global distribution, or the organisation of a 10 x 10 metre quadrant.
Today’s authors (myself and my current supervisors) looked at how species richness changes with land-cover on a municipality scale. We also looked at whether these patterns differ if one considers the total number of species, threatened- or alien ones, and whether animals, plants and fungi react to concrete vs. forests in the same way.
Image Credit: hbieser, Pixabay Licence, Image Cropped
Introduced herbivores restore Late Pleistocene ecological functions (2020) Lundgren et al., PNAS, https://doi.org/10.1073/pnas.1915769117
The fauna of the Pleistocene (also known as the Ice Age) was not that dissimilar to the communities of animals which inhabit our planet now. However, many more large land mammals inhabited all kinds of ecosystems. By the end of the Pleistocene, many of them were extinct, mainly due to climate change impacts (glaciers got larger and restricted their ragne) and prehistoric human impacts like over-hunting, habitat alteration, and introduction of new diseases. The decline of large-bodied herbivores in the Late Pleistocene (LP from here on) led to many ecological changes including reduced nutrient cycling and dispersal, reduced primary productivity, increased wildfire frequency and intensity, and altered vegetation structure. These changes have become our norm.
Scientists usually study species introduction under the premise that they are ecologically novel. However, the introduction of large herbivores has been found to drive changes in the environment, potentially restoring or introducing novel ecological functions similar to pre-extinction Late Pleistocene conditions. This week’s researchers wanted to investigate what sort of role introduced mammals played in restoring ecological interactions by investigating their functional similarity with LP species.
I sat down with leader of the UK Ladybirds Survey Helen Roy to talk about the stigma surrounding invasive species like this Harlequin Ladybird (Image Credit: PJ Taylor, Pixabay Licence, Image Cropped)
While climate change and habitat loss seem to keep making all the headlines when it comes to environmental damage, invasive species are still chugging along comfortably as the second biggest threat to our planet’s biodiversity. New cases are popping up all the time, with the Burmese python, Crucian carp and the emerald ash borer beetle recently reaching new levels of notoriety.
Yet the negative impact that many non-native species have on the habitats they move into have often led to stigmatisation of anything new. This can be counter-productive, as the majority of newcomers into an ecosystem won’t have a pronounced negative effect. And whilst it may seem like a smart piece of preventative management to maintain an ecosystem’s status quo by preventing species introductions, it’s often just not feasible.
With this in mind, I sat down at the recent British Ecological Society’s Annual Meeting with Professor Helen Roy of the UK Centre for Ecology and Hydrology. Helen has studied the impacts of non-native species the world over, from the UK to smaller island nations like St. Helena, and has led several projects for the European Commission on non-native species. We spoke about the importance of distinguishing between invasives and non-natives, the impact of climate change on invasive biology, and the social and cultural significance of both native and non-native species.
Image Credit: California Department of Fish and Wildlife, CC BY 2.0, Image Cropped
Angling as a source of non-native freshwater fish: a European review (2019) Carpio, De Miguel, Oteros, Hillstrom & Tortosa, Biological Invasions, doi.org/10.1007/s10530-019-02042-5
People love fishing. It’s an intrinsic part of some people’s lives, whether as a livelihood or a past-time. People who have grown up fishing often have specific species that they enjoy fishing for. Nothing wrong with that.
Yet people’s desire to go after one fish species will often lead them to move that species around. This can happen on a small scale, with people moving a species from one lake to another slightly closer to their homes. Or it can happen on a massive one, with a species being transported to new continents.
This has shaped entire freshwater communities in modern-day Europe, where 195 species now reside that have no natural range in the continent. Most of these have been introduced since the nineteenth century, which is around the time that fishing became a popular recreational activity. This week’s authors wanted to find out what the role of recreational fishing was in shaping the make-up of today’s invasive freshwater fish populations in Europe.
When we think of global warming, we tend to be a bit selfish and think of how it affects us in our daily lives, but the warming temperatures on our planet have the potential to affect the base of all of our food webs, plants (Image Credit: Matt Lavin, CC BY-SA 2.0).
Phenology in a warming world: differences between native and non-native plant species (2019) Zettlemoyer et al., Ecology Letters, https://dx.doi.org/10.1111/ele.13290
The timing of life-history events (such as births, growing seasons, or reproductive period) is called “phenology”, and this aspect of an organism’s life is particularly sensitive to climate change. So much so that changes in the phenology of certain processes are often used as an indicator of climate change and how it affects a given organism.
We’ve talked about the effects of rising temperatures in animals here on Ecology for the Masses, but there is a lot of evidence in the scientific literature for climate change causing a multitude of different changes in the phenology of various plants. Not only does the direction of the change differ (some organisms experience delays in certain events, others have earlier starts), but the size, or magnitude, of the change also differs. The authors of today’s study wanted to examine these changes in the context of an invasive plant species and how it may be able to outcompete a native plant.
Image Credit: Attack the Block, 2011
We examine the ecology of the BGWMs of 2011’s Attack the Block. Sexual ecology has never been more furry. Or glow-in-the-dark. Actually sexual ecology can get pretty furry. Also we have two fights this week.
3:05 – The Chimera in Cinema
11:41 – Ecology of a BGWM
38:38 – BGWMs vs. Liam Neeson from The Grey
You can also find us on iTunes and Google Play.
In the series Norway’s Newcomers, we’ve looked extensively at not only Norway’s non-native species, but the genetics, definition and even the defense of alien species. So it made sense that we’d eventually find our way to interviewing an invasion biologist. I was in St. Paul, Minnesota earlier this year and was lucky enough to sit down with Professor Mark Davis.
Mark has been a strong opponent of the demonisation of invasive species for decades. Whilst many ecologists’ first reaction is to eradicate any non-native species, Mark has urged caution, and encouraged the community towards less pejorative terms. I spoke with Mark about the impact our work has on public opinion, how we should talk about non-natives, and living with the impact of invasive species going forward.
Lake Superior, the location of the 9th International Charr Symposium (Image Credit: Environmental Protection Agency, Image Cropped)
This week I’ve been lucky enough to represent NTNU at the 9th International Charr Symposium in Duluth, Minnesota, a conference focussing on one of my focal species in the genus Salvelinus. Conferences are like this are great for soaking in a swathe of alternative perspectives, so I thought I’d share a few thoughts from day one of the symposium, including a sign of success, one of innovation, and another of hope.