For anyone familiar with scientific studies or research projects, the common assumption is to set your parameters at the start and to follow them diligently to completion. Varying your methods can alter results or skew an outcome to favoring one thing over another. The process can be applied within the field of ecology and in some way could have been implemented here at Kure. However, this project is far too dynamic and the process for methods done on Green Island falls into a category best termed as adaptive management.
Adaptive management is exactly as it sounds, you adapt your management strategy over time and this is why it is critical to a project such as this one. It might not always be needing to change something that isn’t working but sometimes change the approach to achieve better results in that moment of time. When this project started 6 years ago, you could imagine the approach simply being anything to knock back the dense stands of Verbesina and get the ball rolling in eradicating it. That part was more or less simple. The focus was heavily verbecina and verbecina was found heavily in most places. But what happens when Verbesina is far less abundant and kept in check with regular treatment rotations? What do you do with the space it left and how do you find the few verbecina remaining? These are some of the many questions those in charge face and why adapting strategies is only to the project’s benefit.
Under the concept of better finding the few verb remaining and overcoming the hump to reaching full eradication, the recent transition was transecting naupaka Restoration Areas in full passes. Initially, for some areas, trails were cut through some RA’s and it was from these you would access the RA and treat what weeds you could find from it. Since trails allow ground space and let in more sunlight, they aren’t necessarily ideal as they can quickly become an area hospitable to fast growing weeds. In order to minimize open space and more thoroughly cover these RA’s, recent crews have taken to side-by-side transects that have us zigzagging back and forth between one another, clambering over and squeezing through naupaka branches to search every inch of ground possible. Sound laborious and no doubt it is but there’s an essence of fun to it as well. To achieve full eradication, all verb have to go and especially before they seed and scatter anywhere else.
On the other hand as commonly seen, when you take one thing out of an ecosystem or space something else is obviously going to try and fill that gap if it can. Once areas were cleared of tall standing Verbesina, the ideal want would be for native flora and fauna to be the ones moving in. Initially this took place, however over time varying weather and seasonality allowed for ideal and non-ideal plants to fill in and die back at different rates. They don’t always spread quickly or react under the same accord so sometimes it takes a helping hand. It also takes firm measure to keep those at bay who might arrive, like fast growing weeds, which brings me to the plant Lobularia maritima.
So what about lob? That is, what about the plant more commonly known as Sweet Alyssum found in gardens and landscaping most everywhere. It might not seem like a very noxious weed to many and by no means does it pose the same threat to seabirds as Verbesina does, but all the same its presence here on Green Island isn’t welcome. For the camp of Winter 2015, it seems lob has easily become the most common plant we see in any RA we treat.
With its slender green leaves, delicate white flowers, and sweet smell that offer refuge from the many pungent odors encountered on this island, it’s hard to want to see it gone when you don’t look deep into the matter. The primary goal of this project is to reach full eradication of Verbesina but ultimately all species of invasive/non-native plants as well. One primary reason lob poses such a problem is that the way it grows tends to hide plants around or within it, small verb commonly one of them. It makes our job a whole lot harder to find a plant when it’s buried within a blanket of green leaves and if you chance to miss it and not get back to that RA in time, it could grow out and seed which is what we are trying to avoid. Lob’s further trickery is that Lobularia cotyledons (the first growth form of a sprouting plant) highly resemble Verbesina cotyledons. Needing to count the number of verb we treat, it can be a pain to tease through which is which for such a small plant.
Lob also poses a concern to the growth and abundance of native vegetation by either quickly taking up ground cover or stealing water in its thirst happy habits. In a place where water and space can be limited, you’d see why this is a problem. This is where the story of our winter season gets interesting. Most plants exhibit a flux in growth and a seasonal dieback. When we first arrived on island we were told that we wouldn’t see much lob after our first round of treatments because it tends to die back come December. Well, it never did. It seems the entire time we’ve been here we have seen lob in a continuous state of growth from new seedlings to voluminous plants and the cycle over again. Quite seemingly in some open areas they appear visually to have overtaken much of the ground scape. It isn’t necessarily making our lives difficult but it is making our work tougher as we have to be far more diligent and spend more time in treating areas we could otherwise breeze through more quickly. As for why the lob never fully died back as expected, I’m thinking it has something to do with the change of weather under the El Nino pattern we were in.
I should preface that at some point the going will get better. Once lob shows its normal patterns and the other native vegetation like nohu and alena bounces back, the presence of it will be cut back. For now are work is to keep it in check for future seasons to handle when more readily allowable. This is all part of adaptive management. You never know what scenarios or settings will arise and it takes in the moment judgment to predict what will happen and how you are going to handle it. We took on lob in full force. One day when it is less abundant the plans will change and the approach will be something different.
So come the time we finally get off the island, if your garden or landscaping is missing a certain plant, don’t blame us, it’s seemingly now ingrained in us.
DLNR Kure crew member, Ryan Potter