Beyond Clean Energy: How Solar Parks Are Reshaping Soil Biodiversity and Plant Traits

As the world accelerates toward renewable energy targets, utility-scale solar parks are sprouting across landscapes like never before. Vast fields of photovoltaic (PV) panels now occupy former farmlands, grasslands, and even semi-natural habitats. While their contribution to decarbonisation is celebrated, a quieter, less visible transformation is taking place beneath the panels - and right at ground level. Solar parks are not neutral backdrops; they actively modify soil biodiversity and alter the very characteristics of the plants growing around them. For ecologists, land managers, and the solar industry, understanding these changes is critical to designing more sustainable energy infrastructure.

The solar park mway not give any impression that it is changing all of the time but when you look closer at it from a biology point of view, these panels are actually providing large-scale environmental changes. Panels reflect sunlight and block out sunlight from the ground, which creates different types of environments on the ground. Because of this, there are areas called "hot spots" around the ends of the panels and in the gaps between the rows of panels where the reflected light hits the ground. When sunlight hits the ground, the heat increases. When there is reflection on the ground from the solar panels and, therefore, when things get wet (moisture) on the ground, it creates some localized areas on the ground that are moist and therefore have a higher temperature (drying out) than those areas that are not receiving light from the solar panels.

Just as the biodiversity of plants has been altered by the construction of solar parks, so has their composition and productivity as a result of the environmental characteristics of a solar park's installation. Many species of shade tolerant grass and forbs now inhabit sites that would normally be outcompeted by sun-loving plants (Benner et al. 1996). Some examples include Poa trivialis (rough meadow-grass) and Ranunculus repens (creeping buttercup) which are now more frequently observed growing in proximity to solar panels, while similarly occurring sun-loving species (e.g., Agrostis capillaris [common-bentgrass]) have moved into spaces between installations.

Solar parks not only change plant biodiversity, but they also modify the functional traits possessed by individual plant species. Specifically, as plants grow within the shade of a solar panel, they often develop larger and thinner leaves than plants that grow outside of the solar park setting. In addition, with decreased soil moisture in solar park environments, roots will support less biomass, whilst stems and leaves will support more biomass due to lower water stress on plants growing under solar panels. In addition, flowering times may also be modified and could disrupt the timing of flowering events for pollinators through the alteration of the timing of flowering events of the flower species that have been modified by solar park installation. Finally, in arid regions where solar parks create "oases" composed of higher levels of soil moisture, the mesic adapted species that are now able to survive in solar parks can potentially disrupt the existing patterns of herbivore / predator relationships throughout the food web.

Soil biodiversity is not just about species counts - it is about function. Earthworms, enchytraeids, and collembolans break down organic matter, releasing nutrients for plants. Solar parks alter their activity. Reduced temperature extremes favour earthworm populations in summer, but compaction from construction vehicles can initially decimate them. Over time, however, the combination of shading, reduced tillage (if farming stops), and increased litter from vegetation can rebuild soil structure and enhance carbon sequestration.

Importantly, not all changes are positive. In some designs, panels are placed so close to the ground that light limitation becomes severe, reducing overall plant cover and root exudates - the sugars that feed soil microbes. Monoculture grass sown for "easy maintenance" can lower floral diversity compared to the original habitat. And if herbicides are used to keep panels clean, soil fungal networks may collapse. The net effect depends heavily on solar park design, prior land use, and management practices.

Understanding how these biological factors affect agricultural practices allows us to look at new ways of producing food using solar energy such as the methods referred to as "agrivoltaics" and "eco-solar." By elevating solar panels, spacing them further apart from one another, planting native wildflower seed mixes, and incorporating grazing by sheep or other small livestock, it is possible for developers to transform the land occupied by solar parks into biodiversity-rich regions. In fact, preliminary studies indicate that well-designed solar parks may support greater numbers of various plants and soil-born organisms than agricultural land used for highly intensive agriculture - thereby providing opportunities to establish new forms of semi-natural ecosystems.

For those working within the solar industry - whether they are manufacturers, power producers, or farmers - the message is clear: a solar park is not simply an energy generation facility but rather an ecosystem engineering project. The impact that solar parks have on both plant trait expression and soil biodiversity is significant and measurable, and thoughtful design can often restore previous conditions. Building the renewable energy grid that will be established in the coming years presents a tremendous opportunity - and obligation - for us to make sure that the solar panel's shadow will benefit (through nurturing the biological materials that grow in the shade) as well as provide energy to the living materials below the solar panel.