1 Introduction

Photosynthesis Beavers, belonging to the genus Castor, are renowned for their remarkable ability to alter their environments to suit their needs, earning them the title of quintessential ecosystem engineers. Historically, beavers were widespread across the northern hemisphere, significantly influencing the hydrology, geomorphology, and ecology of their habitats (Westbrook, 2019; Brazier et al., 2020; Larsen et al., 2021). Their activities, primarily dam building, create ponds and wetlands that support a diverse array of aquatic and terrestrial species (Lautz et al., 2018; Washko et al., 2022). The ecological significance of beavers extends beyond mere habitat creation; they play a crucial role in enhancing biodiversity, improving water quality, and increasing the resilience of ecosystems to disturbances (Nummi et al., 2019; Wohl, 2020).

Beavers transform ecosystems through their dam-building activities, which impound water and create extensive wetland areas. These modifications lead to increased surface and subsurface water storage, altered hydrological regimes, and enhanced habitat complexity (Westbrook, 2019; Larsen et al., 2021). The creation of beaver ponds results in a mosaic of habitats that support a wide variety of organisms, including invertebrates, fish, amphibians, birds, and mammals (Nummi et al., 2019; Nummi et al., 2021; Andersen et al., 2023). Additionally, beaver activities influence nutrient cycling and sediment dynamics, contributing to the overall health and functionality of riverine and riparian ecosystems (Rozhkova-Timina et al., 2018; Larsen et al., 2021). The reintroduction of beavers has been shown to restore ecological processes and improve biodiversity in degraded landscapes (Wohl, 2020; Andersen et al., 2023).

This study synthesizes the current scientific understanding of the transformative role of beavers in ecosystems. By examining the impacts of beaver activities on hydrology, geomorphology, water quality, biodiversity, and ecosystem services, this study aims to provide a comprehensive overview of the ecological benefits and challenges associated with beaver engineering. The scope includes both the Eurasian beaver (Castor fiber) and the North American beaver (Castor canadensis), with a focus on their roles in contemporary landscapes across Europe and North America. This study will also explore the implications of beaver reintroduction and management for conservation and ecosystem restoration efforts.

2 Historical Context

2.1 Beavers in prehistoric and early historical times

Beavers have long been recognized as significant ecosystem engineers, with their activities dating back to prehistoric times. Historical and stratigraphic records suggest that hundreds of millions of beavers once modified small to medium rivers throughout the northern hemisphere (Wohl, 2020). Their dam-building activities created diverse habitats, which increased biodiversity and ecosystem resilience. The Eurasian beaver (Castor fiber) and the North American beaver (Castor canadensis) have both played crucial roles in shaping riverine landscapes through their engineering activities (Brazier et al., 2020; Larsen et al., 2021).

2.2 Impact of human activities on beaver populations

The beaver populations faced severe declines due to extensive hunting and habitat destruction. In Medieval times, the Eurasian beaver underwent a significant decline due to habitat loss and hunting pressures (Falaschi et al., 2023). Similarly, in North America, commercial trapping and habitat modification led to a drastic reduction in beaver populations (Wohl, 2020). The cumulative effects of these human activities greatly diminished the ecosystem services provided by beavers, such as increased habitat diversity and nutrient cycling (Nummi et al., 2019; Wohl, 2020).

2.3 Conservation efforts and the resurgence of beaver populations

In recent decades, concerted conservation efforts have led to the resurgence of beaver populations in both Europe and North America. Legal protections and reintroduction programs have been pivotal in this recovery. For instance, the Eurasian beaver population in Europe has rebounded to over 1.5 million individuals due to reintroduction efforts and natural expansion (Brazier et al., 2020). Similarly, contemporary efforts in North America have focused on reintroducing beavers and mimicking their engineering effects through beaver dam analogues (Wohl, 2020). These initiatives have not only facilitated the recovery of beaver populations but also enhanced biodiversity and ecosystem functions (Orazi et al., 2022; Treves and Comino, 2023).

The resurgence of beaver populations has prompted a re-evaluation of their role in ecosystem management. Beavers are now recognized for their potential to provide ecosystem services, such as natural flood management and biodiversity conservation (Figure 1) (Puttock et al., 2021). However, their activities can also lead to human-wildlife conflicts, necessitating balanced management approaches (Falaschi et al., 2023; Treves and Comino, 2023). As beaver populations continue to expand, understanding their ecological impacts and developing effective management strategies will be crucial for maximizing their benefits while minimizing conflicts (Nummi et al., 2019; Brazier et al., 2020; Larsen et al., 2021).

Figure 1 GLM model results between peak Q and total event rainfall, before and after beaver impact at Budleigh Brook and compared to a control site (Colaton Brook). Top: model output plots; Bottom: model summary and marginal mean values for each site (Adopted from Puttock et al., 2021)

3 Beaver Biology and Behavior

3.1 Anatomy and physiology of beavers

Beavers, belonging to the genus Castor, are highly specialized rodents known for their significant impact on ecosystems through their engineering activities. The American beaver (Castor canadensis) and the Eurasian beaver (Castor fiber) exhibit distinct anatomical and physiological traits that enable them to thrive in diverse environments. One of the key features of beavers is their cranial morphology, which is highly adapted to their foraging and feeding requirements. Studies have shown that the skull morphology of beavers is influenced by local environmental conditions such as temperature, precipitation, biomass, and tree hardness, which affect the functional traits of their masticatory system (Diamond et al., 2023). This local adaptation highlights the beaver's ability to modify its phenotype in response to changing environmental conditions, ensuring its survival and efficiency as an ecosystem engineer.

3.2 Social structure and behavior

Beavers are known for their complex social structures and behaviors, which play a crucial role in their ability to modify and manage ecosystems. They live in family units called colonies, typically consisting of a monogamous pair and their offspring from the current and previous years. This social structure facilitates the construction and maintenance of dams and lodges, which are essential for their survival and ecological impact. Beavers are also known for their territorial behavior, marking their territories with scent mounds to ward off intruders. Their dam-building activities create ponds and wetlands, which significantly alter the hydrology and geomorphology of their habitats (Larsen et al., 2021). These modifications not only provide beavers with a stable environment but also create habitats for a wide variety of other species, enhancing biodiversity and ecosystem resilience (Nummi et al., 2019; Orazi et al., 2022).

3.3 Reproductive habits and lifecycle

The reproductive habits and lifecycle of beavers are closely tied to their social structure and environmental conditions. Beavers typically mate for life, with breeding occurring once a year during the winter months. After a gestation period of about 105 to 107 days, the female gives birth to a litter of kits, usually ranging from two to four offspring. The kits are born fully furred and with their eyes open, and they remain in the lodge for the first few weeks of life. Juvenile beavers, known as yearlings, stay with their parents for up to two years before dispersing to establish their own territories. This extended parental care ensures that the young beavers learn essential skills for survival, such as dam building and foraging (Brazier et al., 2020; Treves and Comino, 2023). The lifecycle of beavers, from birth to dispersal, is intricately linked to their role as ecosystem engineers, as their activities during different life stages contribute to the creation and maintenance of diverse and dynamic habitats (Wohl, 2020; Nummi et al., 2021).

4 Engineering Marvels: Beaver Dams and Lodges

4.1 Construction techniques and materials

Beavers (Castor fiber and Castor canadensis) are renowned for their sophisticated construction techniques, which involve the use of a variety of natural materials such as branches, mud, and stones. These materials are meticulously arranged to create semi-permeable structures capable of withstanding significant water flow. Research has shown that beaver dams can endure flow volumes of up to 1.34 m³/s per meter width for a 1.4 m high dam, demonstrating their remarkable engineering capabilities (Müller and Mcfadzean, 2019). The construction process involves the strategic placement of branches and logs to form a sturdy framework, which is then reinforced with mud and stones to enhance stability and water retention (Müller and Mcfadzean, 2019).

4.2 Types and structures of dams and lodges

Beaver dams and lodges exhibit considerable variation in their structure and form, influenced by the landscape setting and available materials. Dams can range from simple, low-head structures to complex, multi-tiered systems that span wide river channels. The physical structure of dams can significantly alter the dynamics of pond storage and water flow, with different dam attributes such as height and length being influenced by the materials used and the water source (Rønnquist and Westbrook, 2021). Lodges, on the other hand, are typically constructed within the ponds created by dams and serve as the primary living quarters for beaver families. These lodges are built with similar materials and techniques, providing a secure and insulated habitat (Müller and Mcfadzean, 2019; Rønnquist and Westbrook, 2021).

4.3 The role of beaver dams in water management

Beaver dams play a crucial role in water management by altering hydrological regimes and enhancing ecosystem resilience. The construction of dams impounds water, increasing surface and subsurface water storage, which can mitigate the effects of drought and reduce flood risks (Larsen et al., 2021; Puttock et al., 2021). By creating ponds and wetlands, beaver dams enhance groundwater retention, reduce stream gradient, and trap sediments, thereby improving water quality and promoting biodiversity (Müller and Mcfadzean, 2019; Brazier et al., 2020). Additionally, beaver dams can attenuate peak flows during storm events, reducing the risk of downstream flooding and contributing to natural flood management (Puttock et al., 2021). The ability of beaver dams to modify hydrological and geomorphological processes underscores their importance as natural water management tools in both contemporary and rewilding landscapes (Larsen et al., 2021; Puttock et al., 2021).

5 Hydrological Impacts

5.1 Alteration of water flow and storage

Beavers are renowned for their ability to alter water flow and storage through the construction of dams. These structures impound water, creating ponds and wetlands that significantly increase surface and subsurface water storage. This alteration in water storage is a primary driver of the hydrological changes observed in beaver-impacted areas. For instance, beaver dams can modify the reach-scale partitioning of water budgets, allowing for site-specific flood attenuation and altering low flow hydrology (Figure 2) (Larsen et al., 2021). The physical structure of beaver dams, including their height and material composition, plays a crucial role in determining the dynamics of pond storage and the overall hydrological impact (Rønnquist and Westbrook, 2021). Additionally, beaver dams can increase evaporation rates and water residence times, further influencing the local hydrological cycle (Larsen et al., 2021).

Figure 2 Conceptual models of the influence of beaver dams on surface and subsurface hydrology (Adopted from Larsen et al., 2021) Image caption: A) specifies different types of beaver dams and through flow; B) Conceptualization of hydrological feedbacks as a result of beaver dam construction on surface and groundwater flow paths and storages. C) illustrates potential hyporheic exchange pathways (Adopted from Larsen et al., 2021)

5.2 Effects on groundwater recharge and surface water dynamics

Beaver dams have a profound impact on groundwater recharge and surface water dynamics. By creating ponds and wetlands, beaver dams enhance the connectivity between surface water and groundwater systems. This increased connectivity facilitates groundwater recharge, particularly during high flow events, and can lead to flow reversals where water moves from the stream to the floodplain (Pearce et al., 2021). The presence of beaver dams also reduces the groundwater-to-stream hydraulic gradient, promoting a more stable and sustained groundwater flow into streams (Pearce et al., 2021). Furthermore, the alteration of surface water dynamics by beaver dams can lead to increased vertical hydraulic exchange gradients and expanded anaerobic conditions, which have significant implications for biogeochemical cycling and nutrient dynamics (Larsen et al., 2021).

5.3 Impact on flood mitigation and drought resilience

Beaver dams play a critical role in natural flood management and enhancing drought resilience. The construction of beaver dams attenuates flow, reducing peak flows during storm events and increasing the lag time between peak rainfall and peak flow (Puttock et al., 2021). This flow attenuation effect is significant even during large storm events, with beaver dams capable of reducing average flood flows by up to 60% (Puttock et al., 2021; Chen and Mai, 2024). Additionally, beaver dams provide temporary surface water storage, which helps to maintain low flow conditions during dry periods and enhances the resilience of the ecosystem to drought (Pearce et al., 2021). The ability of beaver dams to store and slowly release water contributes to a more stable hydrological regime, mitigating the impacts of both floods and droughts (Westbrook, 2019; Rønnquist and Westbrook, 2021).

In summary, beaver dams significantly alter water flow and storage, enhance groundwater recharge and surface water dynamics, and provide critical flood mitigation and drought resilience benefits. These hydrological impacts underscore the transformative role of beavers as ecosystem engineers in shaping river corridor hydrology and enhancing ecosystem resilience.

6 Biodiversity Enhancements

6.1 Creation of diverse aquatic and terrestrial habitats

Beavers are renowned ecosystem engineers, primarily through their dam-building activities, which significantly alter the hydrology and geomorphology of river corridors. These modifications create a mosaic of aquatic and terrestrial habitats that support a wide range of species. For instance, beaver dams increase the extent of open water, creating ponds and wetlands that provide habitats for various aquatic organisms (Larsen et al., 2021). The transformation of terrestrial areas into aquatic ecosystems and the creation of early successional habitats are particularly beneficial for species such as water beetles, which thrive in the heterogeneous environments created by beaver activity (Nummi et al., 2021). Additionally, the increased habitat complexity and heterogeneity resulting from beaver engineering activities promote biodiversity at multiple scales, enhancing both aquatic and terrestrial ecosystems (Willby et al., 2018).

6.2 Increase in plant and animal species richness

The presence of beavers has been shown to significantly increase species richness and abundance across various taxa. For example, studies have demonstrated that beaver-engineered habitats support higher species richness and abundance of terrestrial and semi-aquatic mammals compared to non-beaver areas. This includes notable increases in the presence of species such as moose, otters, and pine martens (Nummi et al., 2019). Similarly, beaver ponds have been found to host a greater number of bird species and higher abundances of bats and birds compared to river and forest habitats (Orazi et al., 2022). The increased structural heterogeneity and productivity of vegetation in beaver-influenced areas also contribute to higher diversity and abundance of invertebrates, such as moths and flying insects (Andersen et al., 2023). These findings underscore the role of beavers in enhancing biodiversity through their ecosystem engineering activities.

6.3 Case studies of biodiversity improvements in beaver-influenced areas

Several case studies highlight the positive impact of beavers on biodiversity. In Klosterheden, Denmark, the reintroduction of beavers led to increased biomass of flying invertebrates and diversity of moths, along with enhanced vegetation productivity and structural heterogeneity (Andersen et al., 2023). In a boreal setting, beaver patches were found to significantly increase mammalian species richness and occurrence, with specific species such as moose and otters showing a preference for beaver-engineered habitats (Nummi et al., 2019). In Germany's oldest national park, beaver ponds supported a higher number of species of conservation concern and greater abundances of birds and bats compared to river and forest plots, demonstrating the beaver's role in promoting biodiversity in mountain forest ecosystems (Orazi et al., 2022). Additionally, in southern Finland, beaver-created wetlands were found to support higher species richness and abundance of water beetles, particularly in newly formed beaver ponds (Nummi et al., 2021). These case studies collectively illustrate the transformative role of beavers in enhancing biodiversity across different ecosystems and geographic regions.

7 Soil and Nutrient Cycling

7.1 Influence on soil composition and erosion control

Beavers, as ecosystem engineers, significantly influence soil composition and erosion control through their dam-building activities. The construction of beaver dams impounds water, which leads to the creation of wetlands. These wetlands enhance sediment deposition, thereby reducing soil erosion and increasing soil stability (Figure 3) (Brazier et al., 2020; Larsen et al., 2021). The increased water retention in beaver-modified landscapes also promotes the development of anaerobic soil conditions, which can alter soil composition by increasing organic matter content and nutrient availability (Larsen et al., 2021). Additionally, the presence of beaver ponds can lead to the formation of new soil layers as sediments settle, further contributing to soil stability and reducing erosion (Brazier et al., 2020).

Figure 3 The influence of beaver activity on the geomorphology of incised streams (Adopted from Brazier et al., 2020) Image caption: (a) low-flow damming of confined channels with high-flow blowouts causes overtopping, bank widening, and excavation of the channel bed; (b) sediment becomes more mobile and the channel reconfigures with vegetation establishment; (c) channel widening reduces high-flow peak stream power and this provides suitable conditions for wider, more stable dams; (d) sediment accumulates in ponds and raises the height of the channel with dams overtopped and small blow-outs occurring where dams are abandoned; (e) process repeats until dams are rebuilt, channel widens and the water table rises sufficiently to reconnect river channel to the floodplain; and (f) high heterogeneity occurs with vegetation and sediment communities establishing themselves, multi-threaded channels and ponds increase reserves of surface water and dams and dead wood reduce flows and provide wetland habitats (Adopted from Brazier et al., 2020)

7.2 Role in nutrient deposition and cycling

Beavers play a crucial role in nutrient deposition and cycling within ecosystems. Their activities increase the residence time of water and nutrients, which enhances nutrient cycling processes (Larsen et al., 2021). Beaver dams trap organic matter and sediments, leading to increased deposition of nutrients such as nitrogen and phosphorus in the soil (Cheng et al., 2019; Larsen et al., 2021). This nutrient enrichment supports microbial activity and plant growth, thereby enhancing the overall productivity of the ecosystem. Furthermore, the creation of wetlands by beavers promotes the development of diverse microbial communities that are essential for nutrient cycling, including nitrogen fixation and decomposition processes (Camenzind et al., 2018; Mercado-Blanco et al., 2018). The increased nutrient availability in beaver-modified landscapes can also lead to higher primary production and greater biodiversity (Nummi et al., 2019; Larsen et al., 2021).

7.3 Benefits to agricultural lands and forest ecosystems

The presence of beavers and their ecosystem engineering activities provide several benefits to agricultural lands and forest ecosystems. In agricultural landscapes, beaver-created wetlands can improve water quality by trapping sediments and nutrients, reducing the need for artificial fertilizers and mitigating the impacts of agricultural runoff (Brazier et al., 2020; Larsen et al., 2021). These wetlands also provide habitat for a variety of wildlife, which can enhance biodiversity and ecosystem resilience (Nummi et al., 2019). In forest ecosystems, beaver activities contribute to soil fertility by increasing nutrient cycling and deposition, which supports tree growth and forest health (Cheng et al., 2019; Legout et al., 2020). The enhanced soil stability and reduced erosion in beaver-modified landscapes also protect forest ecosystems from degradation and promote long-term sustainability (Brazier et al., 2020; Larsen et al., 2021). Additionally, the increased habitat complexity and biodiversity resulting from beaver activities can enhance ecosystem services such as pollination, pest control, and carbon sequestration (Lacher et al., 2019).

In summary, beavers significantly influence soil composition, nutrient cycling, and ecosystem health through their dam-building activities. Their presence benefits both agricultural lands and forest ecosystems by enhancing soil stability, nutrient availability, and biodiversity.

8 Climate Change Mitigation

8.1 Carbon sequestration in beaver wetlands

Beaver wetlands play a significant role in carbon sequestration, which is a critical process for mitigating climate change. The construction of beaver dams leads to the creation of wetlands that can store substantial amounts of carbon. Wetlands are known for their high carbon sequestration potential due to the accumulation of organic matter in anaerobic conditions, which slows down decomposition processes (Were et al., 2019). The presence of beavers enhances this potential by increasing the extent of wetland areas and promoting the deposition of organic material. Studies have shown that beaver-created wetlands can increase carbon storage by expanding the area of anaerobic conditions, which are conducive to carbon sequestration (Willby et al., 2018; Larsen et al., 2021).

8.2 Impact on local and regional climate patterns

Beaver activities can also influence local and regional climate patterns. By creating wetlands and altering hydrological regimes, beavers contribute to increased water storage and evapotranspiration, which can affect local microclimates. The increased surface and subsurface water storage in beaver wetlands can lead to higher humidity levels and potentially moderate local temperatures (Larsen et al., 2021). Additionally, the presence of beaver dams can attenuate streamflow, reducing the severity of droughts and floods, which are expected to become more frequent and intense due to climate change (Puttock et al., 2021). These hydrological changes can have cascading effects on regional climate patterns by influencing the water cycle and energy balance in the landscape (Bailey et al., 2018; Brazier et al., 2020).

8.3 Potential for beaver reintroduction as a climate adaptation strategy

Reintroducing beavers to areas where they have been extirpated is increasingly being considered as a viable climate adaptation strategy. Beavers are recognized as ecosystem engineers that can restore degraded riparian ecosystems and enhance their resilience to climate change impacts. Their dam-building activities can help modulate streamflow, increase water retention, and create diverse habitats that support biodiversity (Bailey et al., 2018; Dittbrenner et al., 2018). The potential for beaver reintroduction is particularly promising in regions where their presence can mitigate the effects of climate extremes, such as floods and droughts. For instance, studies have shown that beaver dams can significantly reduce peak flows during storm events, thereby attenuating flood risks (Puttock et al., 2021). Moreover, the creation of wetlands by beavers can provide refugia for species during dry periods, enhancing the overall resilience of ecosystems to climate variability (Willby et al., 2018). Therefore, beaver reintroduction not only supports biodiversity and ecosystem health but also offers a natural solution for climate adaptation (Bailey et al., 2018; Dittbrenner et al., 2018; Larsen et al., 2021).

9 Human-Beaver Conflicts and Management

9.1 Common conflicts between human activities and beaver behaviors

Beavers, as ecosystem engineers, play a significant role in shaping freshwater ecosystems. However, their activities often lead to conflicts with human interests, particularly in areas where human activities are intensive. Common conflicts include flooding of agricultural lands, damage to infrastructure such as roads and drainage systems, and the felling of trees which can impact both commercial forestry and private property (Rosell and Campbell-Palmer, 2022; Treves and Comino, 2023). These conflicts are exacerbated in landscapes heavily modified by human activities, where the natural behaviors of beavers can clash with human land use and management practices (Rosell and Campbell-Palmer, 2022).

9.2 Strategies for conflict resolution and coexistence

Effective management of human-beaver conflicts requires a multifaceted approach that includes both proactive and reactive strategies. Proactive engagement with affected communities, appropriate communication, and shared decision-making are crucial in preventing conflicts from escalating (Auster et al., 2020). Non-lethal management techniques, such as the installation of flow devices to control water levels and protect infrastructure, have been developed and widely implemented across Europe and North America (Rosell and Campbell-Palmer, 2022). Additionally, financial incentives and compensation schemes can promote tolerance and coexistence by offsetting the costs incurred by land users due to beaver activities (Eeden et al, 2018; Holland et al, 2018). It is also essential to incorporate cultural values and environmental conditions into coexistence strategies to ensure their effectiveness and acceptance by local communities (Eeden et al, 2018; Expósito-Granados et al, 2019).

9.3 Case studies of successful beaver management programs

Several case studies highlight the success of well-planned and executed beaver management programs. The River Otter Beaver Trial in England is a notable example where proactive engagement and appropriate communication with local stakeholders helped mitigate conflicts and fostered a sense of shared responsibility (Auster et al., 2020). In Scotland, the planned reintroduction of beavers in Knapdale, which was science-led and involved extensive stakeholder engagement, faced fewer conflicts compared to unplanned reintroductions in Tayside and the Highlands (Coz and Young, 2020). These examples underscore the importance of structured reintroduction processes and the need for effective discussions involving all stakeholders to agree on long-term conservation plans (Coz and Young, 2020).

In Italy, the potential range expansion of the Eurasian beaver has been modeled to identify areas most likely to be colonized in the near future. This proactive approach helps environmental managers focus on monitoring and mitigating potential conflicts before they arise (Falaschi et al., 2023). Additionally, the use of beavers in natural flood management (NFM) has been explored in England, where downstream communities have been engaged to understand their perspectives and integrate beaver activities into broader flood management strategies (Auster et al., 2020). This catchment-based approach to beaver management and public engagement has shown promise in facilitating coexistence and maximizing the benefits of beaver activities for flood alleviation (Auster et al., 2020).

10 Future Research Directions

10.1 Gaps in current knowledge

Despite the extensive research on beavers as ecosystem engineers, several gaps remain in our understanding of their impacts and management. One significant gap is the variability in hydrological responses to beaver activity across different landscapes and seasons. Studies have shown that beaver dams can attenuate flood flows and reduce peak flows, but the extent of these effects varies spatially and temporally, necessitating further research to understand these dynamics better (Puttock et al., 2021). Additionally, while the role of beavers in enhancing biodiversity is well-documented, there is limited knowledge about their specific impacts on certain taxa, such as invertebrates and amphibians, particularly in lake ecosystems (Bashinskiy, 2020; Andersen et al., 2023). Furthermore, the socio-ecological aspects of beaver reintroduction and management, including human perceptions and conflicts, are underexplored. Understanding local knowledge and perceptions can help develop adaptive management strategies that balance ecological benefits with human needs (Ulicsni et al., 2020).

10.2 Emerging research areas and methodologies

Emerging research areas include the use of advanced monitoring technologies and modeling approaches to study beaver impacts. For instance, continuous hydrological monitoring and high-resolution aerial imagery can provide detailed insights into how beaver dams influence water flow and habitat structure over time (Puttock et al., 2021; Andersen et al., 2023). Additionally, the application of bibliometric analysis to study trends in beaver-related research can help identify emerging themes and guide future studies (Treves and Comino, 2023). Another promising area is the investigation of beaver impacts on climate change mitigation, particularly their role in carbon sequestration and nutrient cycling (Larsen et al., 2021). Moreover, interdisciplinary approaches that integrate ecological, hydrological, and social sciences are crucial for developing comprehensive management strategies. For example, studies that combine ecological data with local knowledge and perceptions can provide a holistic understanding of beaver impacts and inform conflict resolution strategies (Ulicsni et al., 2020).

10.3 Long-term monitoring and impact assessment

Long-term monitoring is essential to assess the sustained impacts of beaver activity on ecosystems and to inform adaptive management. Continuous monitoring of hydrological parameters, such as flow regimes and water quality, before and after beaver reintroduction, can provide valuable data on the long-term effects of beaver dams (Puttock et al., 2021). Additionally, long-term studies on biodiversity, including species richness and abundance of various taxa, can help understand the ecological benefits of beaver engineering over time (Nummi et al., 2019; Andersen et al., 2023). It is also important to monitor the socio-economic impacts of beaver reintroduction, including changes in land use, agricultural productivity, and human-wildlife conflicts. Such comprehensive monitoring efforts can help identify both positive and negative impacts of beavers and guide management practices to maximize benefits while minimizing conflicts (Brazier et al., 2020; Ulicsni et al., 2020). Furthermore, long-term studies on the adaptive potential of beaver populations to changing environmental conditions, such as climate change, can provide insights into their resilience and inform conservation strategies (Diamond et al., 2023).

11 Concluding Remarks

Beavers, as ecosystem engineers, have a profound impact on various ecological and hydrological processes. Their activities, particularly dam building, significantly alter river corridor hydrology, geomorphology, nutrient cycling, and overall ecosystem dynamics. These modifications lead to increased surface and subsurface water storage, altered water budgets, and enhanced habitat complexity and biodiversity. Beavers also facilitate species richness and abundance, particularly in mammals and invertebrates, by creating diverse habitats that support a wide range of organisms. Additionally, beaver activities contribute to early successional habitats, which are crucial for certain species, such as water beetles. The reintroduction of beavers has shown positive effects on biodiversity and ecosystem services, making them valuable for conservation and restoration efforts.

The transformative role of beavers in ecosystem engineering presents both opportunities and challenges for conservation and ecosystem management. Their ability to create and maintain wetlands can be leveraged to restore degraded habitats and enhance biodiversity. However, the impacts of beavers are context-dependent, influenced by local hydro-geomorphic conditions and the duration of their activities at a given site. Effective management strategies should consider these factors to maximize the benefits of beaver reintroduction while minimizing potential conflicts with human activities. Engaging local communities and incorporating their knowledge and perceptions can also help in developing adaptive management practices that balance ecological benefits with socio-economic considerations.

Beavers play a crucial role in shaping ecosystems through their engineering activities. Their ability to create complex habitats and influence ecological processes underscores their importance in biodiversity conservation and ecosystem restoration. As beaver populations continue to expand, it is essential to integrate their ecological functions into management and restoration practices. By doing so, we can harness the natural engineering capabilities of beavers to promote resilient and diverse ecosystems, ultimately contributing to the sustainability of our natural landscapes.

Acknowledgments

Authors sincerely thank all the experts and scholars who reviewed the manuscript of this study. Their valuable comments and suggestions have contributed to the improvement of this study.

Conflict of Interest Disclosure

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

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