Plants might be helping each other more than thought
Contrary to the long-held belief that plants in the natural world are always in competition, new research has shown that, in difficult environments, mature plants help smaller ones to develop and, consequently, to grow.
The first study to examine plant interactions in a hostile environment during their lifetime found that plants that shelter seedlings help smaller plants survive and are more effective themselves, an ecological process called facilitation.
The study, led by Dr. Rocio Pérez-Barrales of the University of Portsmouth and Dr. Alicia Montesinos-Navarro of the Desertification Research Centre of Valencia, Spain, studied adult plants and seedlings in the "ecological desert" of gypsum soil in southeast Spain.
The results could be important for those managing difficult environments, including coastal management.
Dr. Pérez-Barrales said, "If you are a seedling in an arid landscape - on top of a mountain or sand dune, for example - and you are lucky enough to find yourself under a large plant, your chances of survival are certainly better than if you land somewhere alone.
What we found surprising is that a large, well-established plant, called a "nurse", protects a seedling and produces more flowers than the same plants of similar size and tall that grow alone.
This win-win situation for adult plants and seedlings in difficult environments has never been reported before.
"Scientists have often looked at these relationships between plants and found an adult or seedling at some point in their lives, and they have drawn conclusions," said Dr. Pérez-Barrales. "But by studying the entire life span of these plants, from germination and seed establishment, to the growth of young plants and flowering in adult plants, we have evidence that the benefits for both accumulate over time."
Dr. Pérez-Barrales and her all-female team of scientists studied plant growth in southern Spain for three months during the summer. The plants grew in gypsum, a very poor soil, with few nutrients or water.
They found clear evidence that seeding and breastfeeding were more likely to thrive when grown together, compared to either plant growing alone.
The seedling benefited from shade, more moisture and nutrients, litter from the'feeder' plant, and probably higher bacteria and fungi in the soil, among other things. As it matured, the "nourishing" plant produced more flowers than similar plants growing alone in the vicinity, greatly increasing its chances of producing seeds and reproducing.
Other benefits of direct seeding partnerships include that a greater variety of plants growing together can trigger positive cascading effects in the environment. For example, plots of vegetation with food plants and facilitated plants with a higher flower density could attract a greater number and diversity of pollinators to a region, which would promote insect and soil life and even provide a greater variety of different types of fruit to birds and mammals.
"The biggest winner of this plant maintenance system is biodiversity," said Dr. Pérez-Barrales.
"The more biodiversity a region has, the more species of plants, insects, bacteria, fungi, mammals and birds, the greater the chance of a healthy long-term functioning of the environment and ecosystems".
Research is likely to be useful to those who manage and protect plants in hostile and hostile environments, such as pebble and sand dune ecosystems, which surround the United Kingdom and are considered high risk due to human intervention and climate change.
Most amateur gardeners and farmers intend to ensure that their soil and conditions are the best possible for optimal plant growth, but the results could be useful for those who garden in inhospitable areas.
Dr. Pérez-Barrales suggested that gardeners experiment by planting different species of different ages together to test which partnerships help plants thrive in a particular place.
