Conservation planning across realms: Enhancing connectivity for multi‐realm species

Aquatic connectivity: challenges and solutions in a changing climate

The challenge of managing aquatic connectivity in a changing climate is exacerbated in the presence of additional anthropogenic stressors, social factors, and economic drivers. Here we discuss these issues in the context of structural and functional connectivity for aquatic biodiversity, specifically fish, in both the freshwater and marine realms. We posit that adaptive management strategies that consider shifting baselines and the socio-ecological implications of climate change will be required to achieve management objectives. The role of renewable energy expansion, particularly hydropower, is critically examined for its impact on connectivity. We advocate for strategic spatial planning that incorporates nature-positive solutions, ensuring climate mitigation efforts are harmonized with biodiversity conservation. We underscore the urgency of integrating robust scientific modelling with stakeholder values to define clear, adaptive management objectives. Finally, we call for innovative monitoring and predictive decision-making tools to navigate the uncertainties inherent in a changing climate, with the goal of ensuring the resilience and sustainability of aquatic ecosystems.

The challenge of setting restoration targets for macroalgal forests under climate changes

The process of site selection and spatial planning has received scarce attention in the scientific literature dealing with marine restoration, suggesting the need to better address how spatial planning tools could guide restoration interventions. In this study, for the first time, the consequences of adopting different restoration targets and criteria on spatial restoration prioritization have been assessed at a regional scale, including the consideration of climate changes. We applied the decision-support tool Marxan, widely used in systematic conservation planning on Mediterranean macroalgal forests. The loss of this habitat has been largely documented, with limited evidences of natural recovery. Spatial priorities were identified under six planning scenarios, considering three main restoration targets to reflect the objectives of the EU Biodiversity Strategy for 2030. Results show that the number of suitable sites for restoration is very limited at basin scale, and targets are only achieved when the recovery of 10% of regressing and extinct macroalgal forests is planned. Increasing targets translates into including unsuitable areas for restoration in Marxan solutions, amplifying the risk of ineffective interventions. Our analysis supports macroalgal forests restoration and provides guiding principles and criteria to strengthen the effectiveness of restoration actions across habitats. The constraints in finding suitable areas for restoration are discussed, and recommendations to guide planning to support future restoration interventions are also included.

Frameworks for mapping lake ecosystem services. An example from Lithuania

Lake ecosystems are essential for human well-being. Due to its transboundary nature, connecting terrestrial and aquatic habitats, its environmental processes and functions support a wide array of ecosystem services (ES). Hence, despite its importance in supporting socio-ecologic systems, these freshwater ecosystems are highly impacted due to anthropogenic influence. ES may shed light on the importance of maintaining and restoring lake ecosystems. Hence, despite the increased effort in the last decades to provide robust spatial information, most scientific studies still follow a qualitative approach that carries a great deal of uncertainty and is not uptake by decision-makers. It is necessary to develop quantitative and robust methodologies for mapping ES, especially in the aquatic realm. This study develops several frameworks to map ES in lake ecosystems. Important to highlight is that this study.•develops a quantitative multi-method (biophysical and statistical) toolbox for lake ES multi-temporal mapping.•covers five ES from Provisioning, Regulating & Maintenance, and Cultural sections, namely: (1) Fibres and other materials for construction; (2) Water used for non-drinking purposes; (3) Maintenance of nursery populations; (4) nutrient regulation; and (5) recreation.•addresses three dimensions of ES: supply, flow; and demand.

Demystifying ecological connectivity for actionable spatial conservation planning

Connectivity underpins the persistence of life; it needs to inform biodiversity conservation decisions. Yet, when prioritising conservation areas and developing actions, connectivity is not being operationalised in spatial planning. The challenge is the translation of flows associated with connectivity into conservation objectives that lead to actions. Connectivity is nebulous, it can be abstract and mean different things to different people, making it difficult to include in conservation problems. Here, we show how connectivity can be included in mathematically defining conservation planning objectives. We provide a path forward for linking connectivity to high-level conservation goals, such as increasing species' persistence. We propose ways to design spatial management areas that gain biodiversity benefit from connectivity.

Ecological relevance of non-perennial rivers for the conservation of terrestrial and aquatic communities

River conservation efforts traditionally focus on perennial watercourses (i.e., those that do not dry) and their associated aquatic biodiversity. However, most of the global river network is not perennial and thus supports both aquatic and terrestrial biodiversity. We assessed the conservation value of nonperennial rivers and streams (NPRS) in one of Europe's driest regions based on aquatic (macroinvertebrates, diatoms) and terrestrial (riparian plants, birds, and carabid beetles) community data. We mapped the distribution of taxa at 90 locations and across wide environmental gradients. Using the systematic planning tool Marxan, we identified priority conservation sites under 2 scenarios: aquatic taxa alone or aquatic and terrestrial taxa together. We explored how environmental factors (runoff, flow intermittence, elevation, salinity, anthropogenic impact) influenced Marxan's site selection frequency. The NPRS were selected more frequently (over 13% on average) than perennial rivers when both aquatic and terrestrial taxa were considered, suggesting that NPRS have a high conservation value at the catchment scale. We detected an underrepresentation of terrestrial taxa (8.4-10.6% terrestrial vs. 0.5-1.1% aquatic taxa were unrepresented in most Marxan solutions) when priority sites were identified based exclusively on aquatic biodiversity, which points to a low surrogacy value of aquatic taxa for terrestrial taxa. Runoff explained site selection when focusing on aquatic taxa (all best-fitting models included runoff, r²  = 0.26-0.27), whereas elevation, salinity, and flow intermittence were more important when considering both groups. In both cases, site selection frequency declined as anthropogenic impact increased. Our results highlight the need to integrate terrestrial and aquatic communities when identifying priority areas for conservation in catchments with NPRS. This is key to overcoming drawbacks of traditional assessments based only on aquatic taxa and to ensure the conservation of NPRS, especially as NPRS become more prevalent worldwide due to climate change and increasing water demands.