Ecological Function #1
Plants as Food:
- Nectar is an important food source for insects such as butterflies and bees and for some birds such as hummingbirds. As these animals reach deep into a flower where the nectaries are often located, they also perform an essential service for the plant: pollination. Thus, through millennia of co-evolution such species have become codependent on one another. Unfortunately, climate change can alter phenology events so that the timing of flowering might not coincide with the arrival or emergence of pollinators. This poses great risks to both plants and pollinators.
- Because many of these plant parts also contain defensive chemicals, herbivores often need to employ behavioral strategies to avoid or chemical strategies to detoxify or sequester the chemicals. This often results in specialization: adaptations that aid in avoiding the effects of the defensive chemicals enable certain animals to specialize in eating a particular plant species, thereby enhancing their fitness when that plant is abundant in the environment. In turn, this puts greater selective pressure on the plants to modify their defensive strategy. And so it goes, back and forth.
- For a list of keystone plant species that serve as important hosts for specialist insects and birds in your ecoregion, check out this resource. Because these species are important food sources, your refugia garden will better fulfill its refuge function when you include some of these species in it.
- Interestingly, some of the plant defensive chemicals function as herbal medicines for people while others are flavor compounds enjoyed by people. While on the surface this would seem detrimental to a plant, making it more desirable to an herbivore, note that humans actually reward such plants by propagating them. So, which species really comes out ahead?
- Note that plants can sometimes undergo “behavioral” modifications, such as stimulating their meristems (the plants’ growth zones) that are beyond the reach of browsing animals to produce more branches and leaves. This is one of a few ways that plants can take advantage of “spatial” refugia.
Implications for Gardeners:
- Your garden plants are important food sources for wildlife that we care about.
- Plant different species that flower at different times so that pollinators have sufficient food for their survival.
- Include plant species that specialist insects and other wildlife depend on for food.
- To deter excessive animal browsing, we might consider planting an at-risk plant in a spatial refugium.
- Do not be shy about planting species that are delicious to us or are sources of herbal medicines.
1-Diversifying for the future
2-Focusing on ecological functions
Food
Protection
Regulation
Resilience
3-Fitting the natural landscape
4-Co-creating with nature
5-Cultivating relational caring
Refugia Gardening 