Author’s note: Time is running out for Ecuador to save its Amazon rainforests — areas which have 10,000 times the biodiversity of the Galapagos islands. Ethno-ecologist Adam Gebb looks at the problems and possibilities in a seven-part series. This article explores how entire forest communities have to migrate or perish.
By Adam Gebb
As climate change accelerates, millions of wildlife migrations that have never been studied are taking place in the Amazon. The complexity of these movements is beyond human comprehension and our actions are threatening an ecological disaster.
New roads and clearings in Ecuadorian Andes Amazon region have fragmented the region into small pieces that are unable to function by themselves.
Wildlife migration is best facilitated by landscapes that have retained connectivity that is in alignment with local, ancient evolutionary processes. (As described in the previous article in this series)
There are famous migrations such as by the porcupine caribou herd in Canada and that of the monarch butterfly. It’s relatively easy to describe the migrations of many individual species and a lot of information can be found on the topic.
However, forest community migration is poorly understood and therefore there is little information about it to be found. This lack of information and understanding is why we have the 6th great extinction happening now. According to Earth.org, we may be at the tipping point of a collapse of civilization. https://earth.org/sixth-mass-extinction-of-wildlife-accelerating/
Most species have to migrate to meet their year-round food and reproductive needs. If any part of the landscape that holds essential food sources gets developed or damaged, species populations drop and extinctions start occurring. Many species are dependent on broad landscape connectivity in order to succeed. This becomes even truer with full forest community migration.
Some people are familiar with mammal migration which is far simpler to grasp. Just put GPS tracking devices on a group of mammals, wait and watch the data come in. However, forest community migration can’t be tracked as it takes place over thousands of years. It involves continually fluctuating wildlife populations the details of which are often invisible. It’s now understood that at least half of all forest species are under the ground in mycorrhizal communities. Think fungus.
Forest community migration has historically been driven by glacial and interglacial cycles which occur every 20,000-50,000 years. Here we are talking about the movement of entire forest communities of trees, plants, mammals, amphibians, insects and fungi that may travel hundreds of miles over thousands of generations to stay in their comfort zone as the climate warms. In the Ecuadorian Amazon there are millions of species. As they are forced into areas that have different soils and climatic conditions, extinctions as well as genetic variation which increases biodiversity are part of natural evolution. The community is always changing as it moves and will never be the same again.
Here are some examples of forest community migration:
- Global warming is driving entire wildlife communities into higher and cooler areas.
- Powerful wind storms drive the unintentional migration of insects and plant seeds.
- Rivers and their yearly floods redesign entire valleys and take many species down grade.
- Gravity takes seeds and insects down, birds take seeds in all directions.
- As the climate warms, insect communities with narrow temperature bands for successful incubation fail at some lower elevations and succeed in higher areas. If they are tree pollinators then the trees they associate with also go into decline in lower areas. Mammals then migrate into the higher areas where pollinated trees are succeeding and producing more fruit.
- As humans have taken over much of the planet, wildlife communities are drifting in new directions to meet their needs.
The complexity of forest community migration is beyond human comprehension. For example, a University of Wisconsin study found 100,000 different insect species in 2.5 acres of tree canopy. For 99% of those insects, nobody knows what their specific ecological roles are. https://www.youtube.com/watch?v=zibuLbA_Mds
A study of historic forest communities suggests that “Forest communities … are chance combinations of species, without an evolutionary history.”
https://link.springer.com/chapter/10.1007/978-1-4The l612-5950-3_10. This is to say that they are constantly changing and evolving as they move. The interactions are too complex to be understood. This is the truth in any ecological community that has millions of species.
Ecuador’s forests are known to have some of the highest biodiversity on the planet. Forest community migrations are a requirement to avoid falling biodiversity and we don’t understand them. The experts would like it to seem that they understand what is going on out there. But the truth is that they don’t. No one does.
What we do know is that well connected landscapes allow for the migrations of countless species that are impossible to study. The majority of these will be insects which are the fundamental base of most ecosystems. Where insect communities are stable, evolutionary processes that build biodiversity are maintained and countless other species will prosper.
Since forest community migration is so extremely diverse, constantly changing and poorly understood, biocorridors need to be created around the world to give ancient migratory rhythms space to unfold. This will be the topic of the next article in this series.
Adam Gebb is Executive Director of the Andes Amazon Conservancy.