How much of this vegetation is native and how much is not?
I’ve spent a good chunk of my time over the past few months on the coast of Louisiana, mainly on the barrier islands, but I also get to see a lot of marsh on the boat ride out. I also survey a lot of swamp on the drive to and from our launch point, so I spend a large portion of my week looking at green vegetation. And it always amazes me how different the wetlands here are from those in New England, as well as any other wetlands I’ve visited. The same is true for any of the lakes and rivers I’ve jumped into, whether in Europe or the American southwest- so it makes sense that the wildlife and vegetation in each place is a distinct community. But I know that there are real concerns about invasive species around the world, and we’re in danger of homogenizing the diversity out there. Since a look at all invasive species everywhere is far too big a task for one month, I’m going to focus on freshwater and marine invasive plants. It seems both relevant in a conservation context and as we move toward summer activities in the northern hemisphere.
I know a bit about some aquatic invasives- for example, I know that there are restoration efforts in New England to remove phragmites reeds, sometimes by fire, so that native vegetation, such as grasses and cattails, can retake the area- muskrat, and other wildlife species, prefer cattails to phragmites, so restoration is helpful for them as well. I know that milfoil is something you are supposed to look for when you take your boat out of the water for transport to another location- sometimes boats help move plant pieces from lake to lake, facilitating the spread of a species that can choke out native vegetation. And I know a bit about Caulerpa spp. of algae which have created problems in the Mediterranean and been eradicated from San Francisco Bay after several years and several million dollars.
Japanese knotweed is a problem along this river bank in NH
Invasives are a big deal and we tend to provide the highways of invasion. But we can also provide the frontline for resistance and native species conservation. This month I’ll be looking into past and current invasions of aquatic vegetation species, as well as efforts to minimize their spread and impact. In some cases, we may simply have to deal with their presence, but in others hopefully there are ways we can get involved in monitoring and removing non-native threats to native biodiversity. If you enjoy spending time on the water as much as I do, I think it makes sense to be aware how those ecosystems are changing and the role invasive species play in that change. I also think we have a responsibility to be active and give back to the areas we enjoy so much.