1 Introduction

With globalization and technological progress, various parts of the world are experiencing unprecedented urbanization processes (Seto et al., 2013). With the rapid urban expansion, the original natural environment and traditional rural lifestyles are gradually being replaced, engulfed by the wave of urbanization.

The interaction between pollen pollinators and plants is one of the crucial biological processes in ecosystems. These interactions not only involve the reproductive methods of plants, but also affect their genetic diversity, species diversity, and ecosystem stability. Pollen pollinators play a crucial role in plant life history, promoting plant reproduction by transferring pollen from one plant to another (Földesi et al., 2021).

However, the interaction between pollen pollinators and plants goes far beyond this, and there is a complex relationship of interdependence and symbiosis between them. Plants pollinate by attracting different types of pollen pollinators, who rely on the pollen and nectar provided by the plants to obtain food and resources. This interaction leads to diverse symbiotic relationships, covering various biological populations such as insects, birds, bats, etc. (Ashman et al., 2020).

With changes in the ecological environment and interference from human activities, the interaction between pollen pollinators and plants is undergoing changes. Habitat destruction, the use of chemical pesticides, and climate change can all have negative impacts on these relationships. A deep understanding of the mechanisms and impacts of these interactions is crucial for the protection of ecosystems and the maintenance of biodiversity.

This study aims to explore the interaction between pollen pollinators and plants, with a focus on how they affect plant genetic diversity and community dynamics. Starting from different types of pollen pollinators, analyze their symbiotic relationship with plants and their impact on the adaptive evolution of plants. We will delve into how pollen pollinators affect plant genetic diversity, explore the practical applications of these interactive relationships in ecosystem management and protection, as well as work on ecosystem restoration and biodiversity conservation. This study aims to provide ecologists, biologists, and environmental scientists with a comprehensive understanding of the interaction between pollen pollinators and plants, and to provide scientific basis for future research and conservation work.

2 Pollen Pollinator Interaction

The interaction between pollen pollinators and plants plays an important role in different ecosystems, which is of great significance for understanding the structure and function of ecosystems, as well as how to protect and manage biodiversity. A deeper understanding of the interaction between pollen pollinators and plants will help better maintain the balance of natural ecosystems.

2.1 Diversity of pollen pollinators

Pollen pollinators are a diverse group in ecosystems, including insects, birds, and bats. These diverse pollinators play an indispensable role in plant reproduction (Földesi et al., 2021).

Insects are one of the most widespread pollinators of pollen, including bees, butterflies, moths, and beetles (Figure 1). They transmit pollen between flowers to obtain nectar or pollen as a food resource. Different types of insects have different preferences for the pollination methods of plants and the characteristics of flowers, which leads to the formation of various symbiotic relationships. Bees are one of the most common pollinators of pollen, with a highly developed social structure that provides important services for pollination of many crops and wild plants.

Figure 1 Insect honey collection

Birds are also important pollinators of pollen, especially in tropical and subtropical ecosystems in some regions. They usually attract bright flowers and obtain nectar by passing pollen between them. Different types of birds have different beak shapes and flight abilities, allowing them to adapt to different types of flowers. Hummingbirds (Trochilidae) are one of the main pollinators in tropical and subtropical regions, feeding on nectar with their high-speed vibrating wings and long beaks, and transmitting pollen between flowers.

Bats play a special role as pollinators in some ecosystems of certain regions. They usually move around at night and attract light colored flowers. The pollination mechanism of bats typically involves a long tongue that adapts to specific types of flowers. This relationship is particularly significant in some islands and tropical regions. The long nosed bat is a common bat that feeds on nectar with its long and narrow tongue and spreads pollen at night, which is crucial for pollination in some tropical plants.

2.2 The relationship between pollen pollinators and plants

The mutualistic symbiotic relationship is one of the most typical interaction patterns between pollen pollinators and plants (Xiong and Huang, 2019). Plants provide nectar, pollen, or other resources as rewards to attract pollinators to transmit pollen and achieve reproduction. Pollinators obtain food resources through this process, which is a symbiotic relationship that benefits both parties. Pollen competition and strategy are another interactive mode, where various flowers compete for visits from pollinators. Plants may adopt different strategies, such as changing the color, shape, or fragrance of flowers, to attract more pollinators. This competition promotes the diversification of plant traits and helps improve their pollination success rate.

The Pollen Food Network describes the interrelationships between pollinators, where some pollinators may simultaneously attract the same plant, leading to pollen competition. In tropical rainforests, bats feed on nectar and armyworms feed on pollen, forming a complex food web between them. This interactive relationship helps promote pollination and reproduction of diverse plants. This complex network structure is crucial for maintaining the stability and diversity of ecosystems.

2.3 The impact of pollen pollinator interaction

The success rate of plant reproduction is directly influenced by pollen pollinators. Effective pollinators can increase the fertilization rate of plants, increase seed production, and thus affect the growth and distribution of plant populations (Wessinger, 2021).

The evolution of plant traits is also related to the selection of pollinators and the characteristics of flowers. Plants may evolve different traits to attract specific types of pollinators, leading to the formation of plant diversity. Insectivorous plants have evolved special traits, such as sticky leaves, to attract, capture, and digest carnivorous insects, while also obtaining pollen from the insects for transmission (Figure 2).

Figure 2 Fly catchers transmit pollen to feeding on insects

The stability of ecosystems is influenced by the interaction of pollen pollinators. The appropriate number and diversity of pollinators help maintain the stability of ecosystems, ensuring the diversity and normal functioning of plant communities. The diversity and quantity of pollen pollinators affect the structure and diversity of different plant populations in forest ecosystems, thereby affecting the stability and ecological function of the ecosystem.

3 Plant Genetic Diversity

Genetic diversity is a key factor in the health, adaptability, and function of plant populations and ecosystems. Understanding and protecting the genetic diversity of plants is crucial for maintaining ecological balance and biodiversity, especially in the context of environmental changes and ecosystem threats.

3.1 Definition of genetic diversity

Genetic diversity refers to the differences in genotype within a species or between different individuals. It reflects the presence and frequency of different alleles in the gene pool, covering genetic information such as genotype, number of alleles, and allele frequency. Genetic diversity is an important component of biodiversity, which is crucial for the long-term stability and adaptability of plant populations and ecosystems.

3.2 Methods for measuring genetic diversity

Measuring genetic diversity typically involves collecting and analyzing genotype data. Allelic wealth: measures the number of different alleles in a genotype, usually referring to the number of alleles within a certain number of individuals. Heterozygosity: Calculate the average heterozygosity by comparing the two alleles of each individual. Individuals with higher heterozygosity typically have more genetic diversity. Gene frequency distribution: To study the frequency distribution of different alleles in order to understand the relative abundance of different alleles. Molecular markers, including DNA microsatellites, SNPs (single nucleotide polymorphisms) and other molecular markers, can help measure genetic diversity and identify different alleles (Xu et al., 2020).

3.3 The importance of genetic diversity

Genetic diversity plays a crucial role in adaptive evolution. When environmental conditions change, genetic differences between individuals can lead to some individuals being better able to adapt to new environments, thereby increasing the chances of survival for species. This adaptive evolution helps plants survive and reproduce in constantly changing environments, maintaining population stability.

Genetic diversity is crucial for the health and long-term survival of populations. Higher genetic diversity can enhance the population's resistance to environmental changes and stress. When threatened by diseases, pests, climate change, and other factors, populations with greater genetic diversity may be more likely to adapt and survive.

Genetic diversity also has a profound impact on the functioning of ecosystems. Plant species play various roles in ecosystems, including energy flow, material cycling, and soil fertility maintenance. Higher genetic diversity helps maintain these functions, as different genetic variations may lead to different ecological characteristics and traits. This helps to improve the stability of the ecosystem and ensure its normal operation.

4 The Relationship between Pollen Pollinators and Plant Genetic Diversity

Pollen pollinators in the plant world have a profound impact on plant genetic diversity. This interaction helps to maintain the stability and biodiversity of ecosystems. This article will explore the complex relationship between pollen pollinators and plants, including their impact on plant genetic diversity, adaptive evolution of plants towards pollen pollinators, and interactions in community dynamics.

4.1 The impact of pollen pollinators on plant genetic diversity

4.1.1 Hybridization and Gene Flow

Pollen pollinators play an important role in the plant world, promoting hybridization and gene flow between plants. When pollen pollinators transmit pollen across different plant individuals, genetic information can be exchanged between different individuals, leading to new genetic combinations. This helps to increase the genetic diversity of plant populations, making them more resistant and adaptable. Hybridization can also generate new varieties, providing potential opportunities for ecosystem evolution.

Iris tectorum Maxim. is a colorful flower that has evolved strategies to attract insects such as butterflies as pollinators (Figure 3). Due to the various color variations of iris flowers, different colored iris flowers attract different types of butterflies. This leads to butterflies promoting hybridization between different colored iris flowers by transferring pollen from one color of iris to another. This hybridization increases the genetic diversity of iris populations, creates new genetic combinations, and helps iris flowers better adapt to different environments (Zhang et al., 2019).

Figure 3 Iris and butterflies

4.1.2 Maintenance of diversity

Pollen pollinators also help maintain genetic diversity within plant populations. They ensure the mixing of gene pools among different individuals in the plant population by transferring pollen from different plant individuals to the pollinated plants. This diversity helps plant populations better adapt and survive in the face of environmental changes. In addition, diverse pollen pollinators can promote competition and coexistence among different plant species, thereby maintaining the stability of the ecosystem.

Ammania senegalensis Lam. is a widely distributed wild plant with yellow flowers that attract various butterflies as pollinators. Different types of butterflies may visit different flowers, thereby transmitting pollen from different individuals to other plant individuals. The pollinators of this diversity can promote genetic mixing between different plant individuals, helping to maintain genetic diversity within the butterfly grass population.

4.2 Adaptation evolution of plants to pollen pollinators

4.2.1 Selection of pollen pollinators

Plants attract specific pollen pollinators through their evolutionary adaptive characteristics. This includes the color, shape, odor, and rewards generated by the flowers (such as nectar or pollen). This choice helps plants attract the most effective pollinators and increases the success rate of pollen transmission. The adaptive evolution of plants is closely related to the symbiotic relationship between pollen pollinators.

Rhododendrons typically have bright flower colors such as red, pink, or orange, which attract pollinators such as bees (Figure 4). Meanwhile, azaleas provide nectar as a reward to attract bees for pollination. Bees gradually choose to feed on azalea nectar and transmit pollen between flowers, thus maintaining this mutualistic symbiotic relationship. The color and nectar production of azaleas may evolve over time to better adapt to different types of bees.

Figure 4 Rhododendron and honeybees

4.2.2 Evolution of symbiotic relationships

The symbiotic relationship between pollen pollinators and plants is constantly evolving. Plants gradually adjust their flower characteristics to adapt to different pollinators, and pollinators may also evolve more effective methods to obtain plant rewards. This collaborative evolution helps both parties better adapt to each other, thereby improving the success rate of pollination. This symbiotic relationship is crucial for maintaining the stability of ecosystems, as it supports interdependence between different plants and pollinators.

Some plants in the orchid family have evolved special mechanisms for interacting with bees and butterflies. The flowers of orchids usually have complex shapes and colors, attracting bees or butterflies. In addition, some orchids have special structures that can serve as landing platforms for bees, making it easy for them to spread pollen. This symbiotic relationship helps orchids attract suitable pollinators, who also benefit from pollen and rewards (Xiong and Huang, 2019).

4.3 Pollen pollinator plant interactions in community dynamics

4.3.1 Species diversity and stability

The interaction between pollen pollinators and plants is crucial for maintaining species diversity and stability in ecosystems (Ayiguri et al., 2021). These interactions facilitate the coexistence of different plant species, as they can selectively attract different pollinators and reduce the degree of resource competition. This diversity helps ecosystems better respond to external threats and environmental changes.

In an ecosystem, different types of wildflowers can rely on different types of butterflies to spread their pollen. Different butterfly species have different preferences for the color, shape, and aroma of flowers. This leads to diverse symbiotic relationships, allowing various wildflowers to coexist as they attract different types of butterflies and reduce resource competition. This helps to maintain the diversity and stability of wildflowers within the ecosystem.

4.3.2 Species coexistence and competition

Pollen pollinator plant interactions can also lead to competition between species. In some cases, multiple plant species may compete for the same pollinator, which may lead to competition pressure and changes in resource allocation. This competition can prompt species to evolve different strategies to avoid direct competition and thus support coexistence.

An ecosystem that includes a variety of different orchid species. These orchids exhibit unique characteristics in attracting pollinators to reduce competition. Some orchids have evolved strategies for coexisting with specific bee species, as they provide flowers of special shapes and colors to adapt to the mouth and body shape of these bees. Other orchids attract other pollinators, such as butterflies or moths. These strategies reduce competition among orchids, thereby helping them coexist in the same ecosystem.

4.3.3 Community succession

The interaction between pollen pollinators and plants can also affect the succession process of communities. Over time, the relative abundance of different plant species and pollinators may change, leading to changes in the structure and composition of the community. This succession can affect the stability and species diversity of ecosystems.

In polar regions, winters are longer and insect pollinators are fewer, while hummingbirds and wind pollinators (such as wind) play a more important role (Saunders, 2018). As temperatures rise, the number of insect pollinators may increase as more plant species rely on insect pollination. This may lead to changes in the relative abundance of different plant species in the community, as some plants are better adapted to new pollinators. This community succession can affect the structure and function of ecosystems.

5 Practical Applications in Ecosystems

In the practical application of ecosystems, we must find a sustainable balance to meet human needs while protecting and maintaining the ecological balance of the Earth. The management, protection, and restoration of agriculture and natural ecosystems are key components in achieving this goal. We need to take comprehensive measures and actively address ecological challenges to ensure the sustainable future of the Earth.

5.1 Agricultural ecosystem

Agricultural ecosystems are an indispensable part of human life, providing us with the food and raw materials we need. However, agricultural activities also have a significant impact on ecological balance (Ouyang et al., 2019). In order to achieve sustainable development, we need to take measures to protect and improve agricultural ecosystems.

Ecological agriculture practices include organic agriculture, agricultural diversity, and ecological farmland management. These methods aim to reduce the negative impacts of agriculture on soil, water resources, and ecological diversity, and improve the quality and yield of agricultural products. The agricultural ecosystem provides us with important ecosystem services, such as food supply, water purification, and climate regulation. Understanding and maintaining these services is crucial for the sustainability of agriculture. Agricultural ecosystems can also adapt to climate change by adopting new technologies. Intelligent agriculture utilizes data and sensing technology to help farmers manage resources more effectively, reduce waste, and improve productivity.

5.2 Natural ecosystem

Natural ecosystems are the life support systems on Earth, including forests, wetlands, grasslands, and oceans. They play a crucial role in ecological balance, climate stability, and biodiversity conservation.

Protecting the ecological diversity of natural ecosystems is crucial for maintaining ecological balance. Protecting endangered species, establishing nature reserves, and carrying out wildlife conservation work are all key measures. Natural ecosystems can absorb carbon dioxide from the atmosphere and mitigate the impact of climate change. Forests and wetlands play a particularly important role in this regard. Protecting these ecosystems helps to reduce greenhouse gas emissions. Reasonable management of land resources, including opposing excessive development and land degradation, helps maintain the health of natural ecosystems. Sustainable land management methods include forest management, water resource conservation, and soil improvement.

5.3 Protection and recovery

In order to cope with the escalating ecological crisis, we need to take active protection and restoration measures to maintain and restore damaged ecosystems.

Protecting an already relatively intact ecosystem is the most direct measure. This includes establishing nature reserves, national parks, and wildlife reserves to ensure the integrity of the natural environment. For damaged ecosystems, restoration work is crucial. This includes replanting trees, restoring wetlands, and reintroducing wildlife and plants. The restoration of ecosystems can help rebuild ecological balance. Education and public awareness are crucial for the protection of ecosystems. Through education and promotional activities, people can better understand the value of ecosystems, take proactive actions, and support conservation and restoration efforts.

6 Conclusion and Outlook

Pollen pollinators include various organisms such as insects, birds, and bats, who play an indispensable role in plant reproduction. Different types of pollinators have different preferences for plant pollination methods and flower characteristics, leading to the formation of diverse symbiotic relationships. There is a mutualistic symbiotic and competitive relationship between pollen pollinators and plants, which affects the evolution of plant traits and the stability of ecosystems. Pollen pollinators directly affect the success rate of plant reproduction, trait evolution, and ecosystem stability. They play a crucial role in the ecosystem.

Genetic diversity is crucial for the health, adaptability, and function of plant populations and ecosystems, contributing to the survival and evolution of species. Pollen pollinators help maintain plant genetic diversity by promoting plant hybridization and gene flow. They also affect the adaptive evolution of plants to different pollinators. In the management of agriculture and natural ecosystems, we need to maintain and protect the interaction between pollen pollinators and plants to achieve sustainable food production and ecosystem health.

As the impact of climate change becomes increasingly significant, studying how pollen pollinators adapt to climate change and its impact on plants and ecosystems will become a key area. A deeper study of the relationship between genetic diversity and ecosystem function, especially in different ecosystem types, can provide more insights into ecosystem management. Further research and practice need to focus on how to better protect and restore damaged ecosystems to promote the maintenance of biodiversity. Raising public awareness of the interaction between pollen pollinators and plants, as well as ecosystem protection, and encouraging people to take positive actions through educational and promotional activities, will be an important task for the future.

Understanding the interaction between pollen pollinators and plants can help with ecosystem management and conservation efforts to maintain ecological balance. In agriculture and natural ecosystems, we can adopt sustainable methods to meet human needs while protecting the ecological balance of the Earth. The management, protection, and restoration of agriculture and natural ecosystems are also key components in achieving this goal. Through reasonable land management and ecological agricultural practices, we can maintain the health of ecosystems and ensure a sustainable future. Raising public awareness of the importance of ecosystems will also help promote conservation and restoration efforts. Thoroughly studying the complex relationship between pollen pollinators and plants will help to better understand the operation of ecosystems and provide scientific basis for future protection and management work.

Acknowledgments

The author appreciates the revision comments provided by the two anonymous peer reviewers on the manuscript.

Conflict of Interest Disclosure

The author affirms that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

References

Ashman T.L., Alonso C., Parra-Tabla V., and Arceo-Gomez G., 2020, Pollen on stigmas as proxies of pollinator competition and facilitation: complexities, caveats and future directions, Annals of Botany, 125(7): 1003-1012.

https://doi.org/10.1093/aob/mcaa012

PMid:31985008 PMCid:PMC7262468

Ayiguli A., Jiao F.F., and Zhang A.Q., 2021, Pollinator functional groups and their pollen transfer efficiency in heterostylous Limonium kaschgaricum (Plumbaginaceae), Zhiwu Shengtai Xuebao (Chinese Journal of Plant Ecology), 45(1): 51-61.

https://doi.org/10.17521/cjpe.2020.0101

Földesi R., Howlett B.G., Grass I., and Batary P., 2021, Larger pollinators deposit more pollen on stigmas across multiple plant species-A meta-analysis, Journal of Applied Ecology, 58(4): 699-707.

https://doi.org/10.1111/1365-2664.13798

Ou Y.F., Wang L.N., Yan Z., Men X.Y., and Ge F., 2019, Evaluation of insect pollination and service value in China's agricultural ecosystems, Shengtai Xuebao (Acta Ecologica Sinica), 39(1): 131-145.

https://doi.org/10.5846/stxb201809172030

Saunders M.E., 2018, Insect pollinators collect pollen from wind-pollinated plants: implications for pollination ecology and sustainable agriculture, Insect conservation and diversity, 11(1): 13-31.

https://doi.org/10.1111/icad.12243

Wessinger C.A., 2021, From pollen dispersal to plant diversification: genetic consequences of pollination mode, New Phytologist, 229(6): 3125-3132.

https://doi.org/10.1111/nph.17073

PMid:33159813

Xiong Y.Z., and Huang S.Q., 2019, The "trick" of orchids to lure earth bees: sexual deception and pollination, Daziran (China Nature), (3): 30-33.

Xu H., Chen X.M., Lin Z.G., and Ji T., 2020, Microsatellite DNA analysis of the genetic diversity of Apis cerana cerana (Hymenoptera:Apidae) populations at different altitudes in Longshan,Hunan,central China, Kunchong Xuebao (Acta Entomologica Sinica), 63(10): 1260-1267.

Zhang W., He C.B., and Gong Y.B., 2019, Pollinator attraction and outcrossing strategies in Iris, Zhiwu Kexue Xuebao (Plant Science Journal), 37(5): 672-681.