First field trip for the Silva Nova project!
Updated: Sep 28, 2021
Forests are home to a wide variety of species. Countless birds, insects and soil organisms depend on tree species and understory plants to survive. Also, forests are key to regulate processes that benefit us, humans, such as regulation of water and air quality, provisioning of resources, and wood production, among others. The decline of biodiversity we are currently facing is making us alert more than ever for the need to protect and restore our natural ecosystems. Despite many of our efforts to restore biodiversity in forests, we still know very little about the possible directions that nature takes during the restoration process. A simple question such as how long it takes to recover a certain number of species in forest ecosystems is still difficult to answer, because it depends on so many factors, such as management practices, local biodiversity, nutrient status at the time of restoration, climate, among many others.
One of our main interests is to understand how soil biodiversity and respective functions develop over time in planted forests on previous arable land. Creating forests from these arable fields poses a challenge to nature regeneration due to the agriculture legacy left on the soils which is in general reflected by high nutrient availability and altered soil biota and functions. These legacy effects constrain the development of forest-adapted species and affect tree growth, often delaying the development of a forest ecosystem. As a result, restoring the natural conditions of a forest takes a very long time, often centuries.
Fig. 1 | Pictures of visited planted (top and middle panels) and natural (bottom panel) oak forests.
To better understand these impacts we will assess how plant diversity has been developing alongside with the soil biota, including fungi, bacteria, arthropods, and nematodes. We just returned from visiting multiple forests (Fig. 1) that have been planted in different years to assess the biodiversity status of forests at different ages. In addition, we also visited old natural forests (~ 100 years old), which do not have these legacies from agricultural fields, to have an idea of how forest biodiversity naturally develops, and we will also compare our results to those in recent agricultural fields. Our hypothesis is that biodiversity increases as forests have been established for a longer period, diverging from the agriculture setting.
Besides from trying to understand if biodiversity increases as forests get older, we will also investigate if the interactions between the species are being restored. We expect that more species will be found to occur together more often as forests grow older, which is very important for ecosystem recovery by increasing ecosystem stability. For example, mycorrhizal fungi (e.g. mushrooms) help plants obtain nutrients from the soil and should increase over time, which is crucial to increase plant productivity and health.