Plant diversity, less pesticide

Increased plant diversity enhances the natural control of herbivorous pests in grasslands. Plant-rich plant communities support natural predators and at the same time provide less valuable food for vegetarians. The discovery was made by a team of researchers led by the German Center for Integrative Biodiversity Research (IDIV). In conducting two similar experiments, their results were published Science progress And show that increasing plant biodiversity can help reduce pesticide inputs in agricultural systems by increasing natural biological control.

Biodiversity, the biodiversity of all species on Earth, their interactions and the different ecosystems they form are crucial to providing and maintaining ecosystem functions and services in plantations and natural grasslands. Along with the growing demand to feed the world’s growing population through intensive agriculture, these grasslands are also under pressure. Pest vegetarians are causing an estimated 18-26% loss in global crop production, which has led to significant growth in the use of environmentally expensive pesticides.

To investigate how plant diversity can naturally reduce plant growth and the effects of plants, the German Center for Integrative Biodiversity Research (IDIV), the University of Leipzig (UL) and the Friedrich Schiller University (FSU) The team used two long-running meadow biodiversity experiments in Europe and North America: one in Germany and one in Cedar Creek Biodiversity in Minnesota (USA). Over the course of two years, scientists collected data from these two similar experiments, providing a deeper understanding of the food web structure of monogamous cultures and species-rich meadows. “Both of these long-term experiments have provided invaluable insights for both basic and applied research, highlighting the importance of biodiversity conservation,” said Nico Eisenh, a senior author and professor at UL and head of IDEV’s research team. As the speaker of his experiment.

Diverse vegetable communities are less appealing to vegetarians

Researchers have found that plants in more diverse communities lose significantly less exposure to herbivores. In the high-diversity mix, the rate of vegetarian feed per gram of vegetable biomass was 44% lower than monotony. Thus, for every gram of plant biomass produced, the plant loses as much as half of the arthropod vegetarians when planted in species-rich communities. “This ultimately means that where multiple species are planted together, more plant biomass per square meter will be obtained, and each plant in different mixtures will suffer less damage from herbivores,” said Andrew Barnes, the first author and idiom aluminus, now a senior lecturer. . Waikato University in New Zealand.

In patches of high plant diversity, arthropod herbivores are less likely to cope with their preferred plant species – making it less likely that they will be in these high-variety patches. In addition, previous research has shown lower levels of tissue protein (nitrogen) in plant communities, with higher species richness, making these plants less nutritious for vegetarians.

Hunters take advantage of a variety of plants

Although total biomass of both herbivores and predators increased in plant-rich meadows, hunters from different plant communities benefited more strongly: compared to monocultures, they increased significantly in both their total biomass and food rates. One possible explanation may be that arthropods such as spiders, some beetles, or wasps benefit significantly from the more complex habitats of high-variety plant communities, reducing the risk of being eaten by vertebrate predators such as birds and mammals.

Increasing plant diversity, thus, has many positive side effects: Compared to monotony, high-diversity plant communities produce more total biomass. In addition, both natural enemies and equipment concentration work to limit the negative effects of vegetarians on plant performance. Rew Andrew Barnes said: “In other words, more diverse vegetable communities pose a dual problem for vegetarians – i.e. more predatory and less preferred foods – which can help reduce herbivore effects naturally.”

Plant biodiversity can limit the spread of herbivorous organisms

In contrast, pesticide control, which relies heavily on pesticides, can lead to harmful reduction of herbivore pests, as pesticide use can destabilize communities of natural enemies. “Our experiments show that preserving plant diversity provides a number of benefits for controlling plant pests, which can play an important role in reducing the inputs of agrochemicals and increasing plant productivity.” Nico Eisenhower added: “Ultimately, this study shows that supporting biodiversity can benefit sustainable management of ecosystems and people.”

Provided by the German Center for Integrative Biodiversity Research