Pollinators are critical to the survival of both natural ecosystems and human agriculture. These animals facilitate the transfer of pollen between plants, enabling the process of pollination, which is essential for plant reproduction. A staggering 85% of wild plants and over 70% of cultivated plants rely on pollination to reproduce. This process is integral not only to the survival of plant species but also to the production of the majority of the food we consume. However, the growing challenges posed by climate change, habitat destruction, and intensified farming practices are causing a decline in pollinator populations worldwide. This decline threatens biodiversity and the stability of ecosystems, making the protection of pollinator species more urgent than ever.
One significant contributor to the growing body of research in this field is Maddi Artamendi, a researcher at the University of the Basque Country (UPV/EHU). Artamendi, alongside Ainhoa Magrach, an Ikerbasque Research Professor at BC3, has conducted pioneering research to address the critical issue of pollinator diversity. Their findings, recently published in Nature Ecology & Evolution, underscore the importance of maintaining a wide array of pollinator species—not just for agriculture, but for the broader health of ecosystems.
Artamendi explains, “In most of the studies conducted on this issue across the world, plants were found not to bear fruit if no pollinator was present. Studies of this type have mostly been conducted on crop species, but that does not give a true picture. The diversity of pollinators is already decreasing, and this trend is set to continue, but the decline will not mean that pollinators will disappear entirely.” The research team aimed to present a more realistic view by considering both crop and wild plants in their analysis, providing a comprehensive understanding of how pollinator diversity affects plant reproduction.
The researchers’ study highlights several key points regarding the impact of pollinator diversity on plants. First, they found that the decline in pollinator diversity significantly impacts the reproductive success of plants, affecting the number of fruits, the quantity of seeds, and the overall weight of the fruits produced. Interestingly, this effect was found to be more pronounced in wild plants than in cultivated ones. Artamendi further notes that even plants that are self-pollinating, which were previously thought to be less reliant on external pollinators, also benefit from pollen exchange with other plants. The findings reveal that self-pollinating species still show improved reproductive success when pollinators are present, reinforcing the importance of maintaining a diverse and healthy population of pollinators.
Moreover, the study revealed an important distinction between domestic and wild pollinators. While honey bees, the most well-known domestic pollinators, are often the focus of pollinator conservation efforts, the study found that wild pollinators had a greater influence on the reproductive success of plants than their domestic counterparts. “The decline in the diversity of wild pollinators further exacerbates the reproductive success of plants,” said Artamendi, underscoring the importance of preserving not just honey bees but a range of pollinator species, including wild insects, birds, and bats.
The research further categorizes the decline in pollinator populations, showing that invertebrate pollinators (such as bees, butterflies, and moths) are experiencing a greater loss than vertebrate pollinators. Additionally, nocturnal pollinators—such as bats and moths—are declining at a faster rate than their diurnal counterparts. These patterns suggest that certain pollinator groups, particularly those that are active at night or have more specialized habitat requirements, are more vulnerable to the pressures of climate change and habitat loss.
The study utilized meta-analysis, a research method that compiles and analyzes data from multiple studies to identify broader patterns and trends. The researchers examined 207 individual studies conducted across 46 countries, representing a wide variety of plants, pollinators, and environmental conditions. This global approach allowed Artamendi and Magrach to create a more accurate and quantifiable picture of the state of pollinator populations and their effects on plant reproduction.
“We analyzed research done across the world,” Artamendi explained. “We had to take into account different plant varieties depending on the climate, the varying effects on different plants, the size of the sample, and many other variables. By considering these factors, we were able to ensure that our findings were comprehensive and applicable to a wide range of scenarios.” The meta-analysis also helped identify gaps in research, revealing areas where further studies are needed, particularly in underrepresented regions or for certain plant and pollinator groups.
The findings of this research challenge the conventional focus on domestic pollinators and highlight the need for a more holistic approach to pollinator conservation. “All pollinators play a role, both in crop plants and in wild plants. We cannot focus on domestic pollinators alone. There are more pollinators, and they are all of great importance to the reproductive success of plants and in maintaining plant diversity,” said Artamendi. This broader perspective, which takes into account the diverse array of pollinator species, is essential for ensuring the health of both agricultural systems and natural ecosystems.
Artamendi’s study is part of a broader thesis she is working on under the supervision of Ainhoa Magrach and Arantza Aldezabal, a lecturer and researcher at UPV/EHU. Their work contributes to a growing body of evidence that underscores the urgent need to protect pollinator diversity. As the study makes clear, the decline of pollinators, especially wild pollinators, poses a serious threat to the sustainability of ecosystems and the plants that depend on them.
The research also has important implications for policy and conservation efforts. In many countries, the focus of pollinator protection programs has been primarily on honey bees, often to the detriment of other pollinator species. This study argues for a more inclusive approach, one that recognizes the value of all pollinators, from wild bees to birds and bats, and addresses the broader environmental factors that contribute to their decline. Artamendi and Magrach emphasize the importance of habitat preservation, sustainable farming practices, and addressing climate change in efforts to protect pollinators.
More information: Maddi Artamendi et al, Loss of pollinator diversity consistently reduces reproductive success for wild and cultivated plants, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02595-2