Ecosystem restoration efforts play a crucial role in fostering greater ecological complexity and addressing the limitations of conventional approaches¹. While many restoration initiatives primarily focus on carbon sequestration through tree planting, it is imperative to consider the broader dynamics of energy and water fluxes within ecosystems². Vegetation significantly influences the hydrological cycle, which involves the continuous circulation of water through the land, atmosphere, ocean, and surface water bodies. Particularly critical is the role of vegetation in land-atmospheric moisture transport through evapotranspiration^3,4, as this directly affects terrestrial water availability through the infiltration and percolation of water into the soil⁴ and ultimately also local cloud formation and precipitation patterns^3,5,6,7. On a global scale, it is shown that the majority of terrestrial precipitation depends on moisture derived from land^8,9.

Neglecting these interactions when changing the landscape (e.g. through restoration, de- or afforestation programs) could lead to problematic ecohydrological outcomes^10,11, such as decreased runoff and groundwater recharge due to an increase in plant root water uptake after afforestation^12,13. Beyond the local effects, large-scale land cover change has shown to have strong atmospheric effects in empirical and modelling studies⁷. Particularly in coastal regions, where forest loss can, for example, lead to a drastic reduction in land-inward moisture flux, resulting in a decreasing precipitation trend downwind and the risk of shifting the inland regime from wet to dry^14,15. In contrast, it has also been shown that desert plantations can be used to deliberately enhance rainfall locally¹⁶.

Numerous studies have utilized satellite data to examine the causal relationship between vegetation and precipitation and reveal diverse effects on local-to-regional water availability^17,6. However, there is a consensus among researchers that vegetation holds potential as a strategy to modify local water availability¹⁸. Notably, Jiao¹⁹ demonstrated a positive correlation between vegetation and water availability, as illustrated in Figure 1.

This finding supports the notion that vegetation can contribute to increased water availability in certain contexts. However, it is essential to recognize that the relationship between vegetation and water availability is not universally consistent and can exhibit location-specific variations¹⁷.

Overall, vegetation plays a crucial role in controlling local water availability through its influence on land-atmosphere fluxes, water infiltration, and soil percolation. Understanding these ecosystem dynamics and the role of vegetation in the water cycle is crucial for managing and conserving water resources²⁰ and allows us to recognize the potential risks and adopt a more holistic, deliberate approach. Whereby restoration efforts can promote biodiversity, leverage excess nutrients in water bodies, and ensure sustainable ecological restoration outcomes^21,22.

Blending Natural Cycles and Engineered Processes:

The remarkable aspect of ecosystem restoration lies in the harmonious integration of natural cycles with engineered processes²³, also known as Bio-geoengineering¹⁶. By harnessing the inherent power of nature and incorporating carefully designed interventions, we can shape and direct ecosystem dynamics. The selection of specific algae, plant, and animal species plays a pivotal role in establishing diverse habitats, each contributing to the overall resilience of the ecosystem^24,25. Moreover, the flexibility to set varying soil depths across different land ecosystems enables the creation of many habitats within a limited space, fostering greater biodiversity and ecological complexity²⁶.

One of the leading examples of incorporating scientific knowledge of ecosystem dynamics and the integration of natural cycles and engineered processes, such as phytoremediation and ecohydrology, in ecosystem restoration is the Eco Oasis (Fig. 2). It is a dome-shaped greenhouse that integrates multiple interconnected habitats to establish a controlled environment for water, energy, and nutrient cycles. This synergy fosters accelerated biodiversity development, facilitating interactive and symbiotic processes among diverse life forms. Phytoremediation refers to the use of plants to mitigate environmental pollution²⁷, while ecohydrology explores the interactions between ecological processes and hydrological systems²⁸. By blending these natural cycles and engineered processes, the Eco Oasis project exemplifies a holistic approach to ecosystem restoration, ensuring the effective management of ecological resources and the restoration of vital ecosystem services. The Eco Oasis seeks to replicate and study these dynamics by mimicking natural ecosystems. This involves understanding and monitoring the flow of energy, nutrients, and matter among the various components of an ecosystem.

Nutrient Cycling:

Addressing nutrient imbalances in water and soil is crucial for achieving sustainable ecosystem restoration²⁹. Excessive nutrient loadings of compounds based on nitrogen and phosphorus can lead to eutrophication and disrupt the delicate ecological balance of natural ecosystems²⁵. Innovative approaches are being employed to remove these excess nutrients from ecosystems, restoring water quality and supporting the growth of diverse life forms. By utilizing natural processes such as phytoremediation, nutrient-rich waters can be purified as they interact with vegetation, effectively eliminating harmful substances and fostering ecological restoration³⁰.

Nutrient cycling is an essential concept applied in the Eco Oasis. The system is designed to utilize surplus nutrients from the water to foster biodiversity³¹. As water passes through the different stages of the ecosystem, it supports the growth of various life forms, ranging from algae to higher organisms such as trees, reeds, microcrustaceans, molluscs, amphibians, and fish. This process contributes to rebalancing water quality and nutrient cycling, ultimately leading to increased biodiversity within the system³¹. By effectively managing and recycling nutrients, the Eco Oasis creates a self-sustaining environment that fosters the growth and development of diverse species, further enhancing the ecological dynamics and potential for harmonious coexistence with nature.

Monitoring Vegetation Dynamics:

Monitoring vegetation dynamics is essential for assessing the health and progress of ecosystem restoration efforts³². Through continuous observation, scientists gain valuable insights into the response of different plant species to changing environmental conditions, which in turn contributes to the preservation of biodiversity. By monitoring vegetation dynamics, researchers can identify shifts in species composition, detect changes in habitat suitability, and track the presence of rare or endangered plant species³³. This knowledge allows for refining restoration strategies and optimising vegetation selection to maximize impact²⁵. Furthermore, tracking vegetation dynamics enables the identification of invasive species, prompting the development of effective measures to mitigate their negative effects and preserve ecosystem integrity³⁴.

Revitalizing the Soil:

Soil degradation significantly threatens ecosystem health and productivity through reduced nutrient availability, erosion and loss of topsoil, soil compaction, soil organic matter, and altered soil structure and function³⁵. However, by implementing restoration techniques, we can revitalize the soil and create fertile environments for plant growth. Practices such as the application of organic matter, biochar and beneficial microbes can improve the soil structure, and increase nutrient availability and water retention capacity²⁵. Soils are a vital natural resource that host vast biodiversity in terms of species, abundance and functions. These organisms and their interactions are essential to the processes and functions of the soil, and thus, enhance soil’s ability to decompose organic matter, regulate nutrients, pest regulation, and soil structure development³⁶. The aggregate soil functions provide significant ecosystem services for society, such as climate regulation, food production, and provision of clean water³⁷. By restoring the soil, ecosystem restoration efforts establish a solid foundation for sustained growth, biodiversity, and ecosystem services³⁸. Therefore, the application of the Eco Oasis model catalyses soil revitalization and fosters quality soils through the promotion of higher biodiversity and providing ideal conditions for optimal soil functions in a comprehensive approach.

Conclusion:

Understanding ecosystem dynamics and the role of vegetation in the water cycle is crucial for managing water resources and maintaining ecosystem health. Successful ecosystem restoration requires monitoring vegetation dynamics, addressing nutrient imbalances, and revitalizing the soil. Restoring and preserving healthy ecosystems not only provides essential services such as clean water, air purification, and climate regulation but also enhances community resilience and sustainable livelihoods. To effectively tackle climate change and promote resilience, a holistic approach that empowers nature and harnesses ecosystem services is needed. It is important to invest in research and mainstream ecosystem-based solutions, while also understanding the local and downstream effects of ecosystems on weather and land-atmosphere processes. Integrating natural cycles and engineered processes is key to enhancing ecosystem resilience and achieving effective ecosystem restoration for long-term ecological health.

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