Special section: Conserving nature's stage

A framework for quantifying geodiversity at the local scale: a case study from the Rokua UNESCO Global Geopark

Geoconservation and related quantitative and qualitative geodiversity assessments are gaining increasing attention. However, methodologies for measuring geodiversity at local scale are currently rare. Here, we present a framework for assessing local-scale geodiversity of different landforms using field-based and digital elevation model (DEM-) derived data from the Rokua UNESCO Global Geopark in Finland. We observed the presence or absence of various geodiversity elements, such as geological or topographical elements in our study sites, and used these data to quantify alpha (α), gamma (γ) and beta (β) geodiversity of various landforms. In addition, we measured topographical heterogeneity in the field and from DEMs. The results showed distinct patterns in the geodiversity and topographical variation of the landforms. The differences between α, γ and β geodiversity of different landforms were particularly clear. According to the results, measures of topographical variability can be used to some extent as surrogates for geodiversity, but the choice of optimal variables is context and scale dependent. These results provide perspectives for further local-scale geodiversity assessments in different study areas and are applicable for a range of purposes, from scientific research to practical management and geoconservation. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Towards a taxonomy of geodiversity

Geodiversity is a topical concept in earth and environmental sciences. Geodiversity information is needed to conserve nature, use ecosystem services and achieve sustainable development goals. Despite the increasing demand for geodiversity data, there exists no comprehensive system for categorizing geodiversity. Here, we present a hierarchically structured taxonomy that is potentially applicable in mapping and quantifying geodiversity across different regions, environments and scales. In this taxonomy, the main components of geodiversity are geology, geomorphology, hydrology and pedology. We propose a six-level hierarchical system where the components of geodiversity are classified at progressively lower taxonomic levels based on their genesis, physical-chemical properties and morphology. This comprehensive taxonomy can be used to compile geodiversity information for scientific research and various applications of value to society and nature conservation. Ultimately, this hierarchical system is the first step towards developing a global geodiversity taxonomy. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Geodiversity data for Europe

Geodiversity is an essential part of nature's diversity. However, geodiversity is insufficiently understood in terms of its spatial distribution and its relationship to biodiversity over large spatial extents. Here, we present European geodiversity data at resolutions of 1 km and 10 km. We assess terrestrial geodiversity quantitatively as a richness variable (georichness) using a commonly employed grid-based approach. The data incorporate aspects of geological, pedological, geomorphological and hydrological diversity, which are also available as separate richness variables. To evaluate the data, we correlated European georichness with empirically tested national georichness data from Finland, revealing a positive correlation at both 1 km (rp = 0.37, p < 0.001) and 10 km (rp = 0.59, p < 0.001) resolutions. We also demonstrate potential uses of the European data by correlating georichness with vascular plant species richness in two contrasting example areas: Finland and Switzerland. The positive correlations between georichness and species richness in Finland (rp = 0.34, p < 0.001) and Switzerland (rp = 0.26, p < 0.001) further support the use of our data in geodiversity-biodiversity research. Moreover, there is great potential beyond geodiversity-biodiversity questions, as the data can be exploited across different regions, ecosystems and scales. These geodiversity data provide an insight on abiotic diversity in Europe and establish a quantitative large-scale geodiversity assessment method applicable worldwide. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Geodiversity in the Amazon drainage basin

The Amazon is the largest drainage basin on Earth and contains a wide variety of abiotic landscape features. In spite of this, the geodiversity in this basin has not yet been objectively evaluated. We address this knowledge gap by combining a meta-analysis of an existing global geodiversity map and its components with a systematic literature review, to identify the key characteristics of geodiversity in the Amazon drainage basin (ADB). We also evaluate how these global geodiversity component maps, that are based on the geology, geomorphology, soils and hydrology, could be refined to better reflect geodiversity in the basin. Our review shows that geology-through lithological diversity and geological structures-and hydrology-through hydrological processes that influence geomorphology and soil diversity-are the main determinants of geodiversity. Based on these features, the ADB can be subdivided into three principal regions: (i) the Andean orogenic belt and western Amazon, (ii) the cratons and eastern Amazon, and (iii) the Solimões-Amazon river system. Additional methods to map geomorphological and hydrological diversity have been identified. Future research should focus on investigating the relationship between the geodiversity components and assess their relationship with biodiversity. Such knowledge can enhance conservation plans for the ADB. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Case studies associated with the 10 major geodiversity-related topics

This paper outlines the 10 major topics related to geodiversity that have emerged since the concept was first introduced in 1993, 30 years ago. After a short introduction, each of the 10 topics is then illustrated by a relevant case study. The 10 topics (italics) and their case studies (bold) are as follows: 1. Celebrating, International Geodiversity Day; 2. Measurement/Assessment, Potential role of remote sensing; 3. Natural Capital and Geosystem Services, Coastal geosystem services; 4. Biodiversity, Mangue de Pedra, Brazil; 5. Geomaterials, The circular economy; 6. Geotourism, World's top geotourism sites?; 7. Geoheritage, Landscape restoration; 8. National Geoconservation, Trump golf course and an SSSI, Scotland; 9. World Heritage Sites and Global Geoparks, Azores Global Geopark, Portugal; 10. Sustainability, Xitle Volcano, Mexico City. It is concluded that, given the way in which geodiversity has developed as a concept, leading to new insights and avenues of research and advancing our understanding of the world since its first use, it clearly now constitutes a significant, geoscientific paradigm. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Boundary of ecosystem services: A response to

Chen et al. (2023) have proposed a scheme to define which services should be included as ecosystem services and which should be excluded so as to avoid "an all-encompassing metaphor that captures any benefit". We discuss the proposals, drawing attention in particular to definitions of 'natural capital' and 'ecosystems', the complexities of separating biotic from abiotic flows, and the importance of geodiversity and geosystem services in delivering societal benefits. We conclude that rather than trying to separate out bits of nature in order to draw the boundary of ecosystem services, it is perhaps time to avoid using 'nature' and 'biodiversity' as synonyms and think instead of a more holistic and integrated approach involving 'environmental', 'natural' or 'nature's services', in which the role of abiotic nature is fully recognised in both ecosystem services and non-ecosystem domains.

Acknowledging geodiversity in safeguarding biodiversity and human health

Our existence on Earth is founded on a vital nature, which supports human physical and mental health. However, nature is often depicted only through biodiversity, whereas geodiversity-the diversity of non-living nature-has so far been neglected. Geodiversity consists of assemblages, structures, and systems of geological, geomorphological, soil, and hydrological components that fundamentally underlie biodiversity. Biodiversity can support overall human health only with the foundation of geodiversity. Landscape characteristics, such as varying topography or bodies of water, promote aesthetic and sensory experiences and are also a product of geodiversity. In this Personal View, we introduce the concept of geodiversity as a driver for planetary health, describe its functions and services, and outline the intricate relationships between geodiversity, biodiversity, and human health. We also propose an agenda for acknowledging the importance of geodiversity in health-related research and decision making. Geodiversity is an emerging topic with untapped potential for ensuring ecosystem functionality and good living conditions for people in a time of changing environments.

Adaptation Strategies and Approaches for Managing Fire in a Changing Climate

As the effects of climate change accumulate and intensify, resource managers juggle existing goals and new mandates to operationalize adaptation. Fire managers contend with the direct effects of climate change on resources in addition to climate-induced disruptions to fire regimes and subsequent ecosystem effects. In systems stressed by warming and drying, increased fire activity amplifies the pace of change and scale of severe disturbance events, heightening the urgency for management action. Fire managers are asked to integrate information on climate impacts with their professional expertise to determine how to achieve management objectives in a changing climate with altered fire regimes. This is a difficult task, and managers need support as they incorporate climate adaptation into planning and operations. We present a list of adaptation strategies and approaches specific to fire and climate based on co-produced knowledge from a science–management partnership and pilot-tested in a two-day workshop with natural resource managers and regional stakeholders. This “menu” is a flexible and useful tool for fire managers who need to connect the dots between fire ecology, climate science, adaptation intent, and management implementation. It was created and tested as part of an adaptation framework used widely across the United States and should be applicable and useful in many fire-prone forest ecosystems.

Spatial heterogeneity and temporal stability characterize future climatic refugia in Mediterranean Europe

Climate plays a major role in shaping biodiversity patterns over time and space, with ongoing changes leading to the reorganization of ecosystems, which challenges conservation initiatives. Identifying areas that could serve as possible climate change refugia for future biodiversity is, thus, critical for both conservation and management. Here, we identify potential future climatic refugia within the Euro-Mediterranean biome, which is a global biodiversity hotspot, while accounting for multiple emission climate change projections over the next 50 years. We developed two metrics of climatic variability: temporal stability and spatial heterogeneity. We then used a systematic conservation planning approach to identify climate-based priority areas. While we used a climate-based, species-neutral methodology, we deliberately implemented low climatic velocity thresholds, so that the identified climatic refugia would even be compatible with the needs of species with low dispersal capacity, such as plants. Our projections showed that future climatic refugia would be more frequently observed in mid-altitudes, for gradients with steep elevations, and mainly in the eastern part of the Euro-Mediterranean biome, with possible conflicts with existing land uses and future conservation implications. Climatic, land use, and topography results indicated that only a limited number of refugia would be hosted by high elevation habitats (>1500 m), raising possible concerns about the biodiversity of Mediterranean mountain regions. Our analyses show that the current network of protected areas captures future climatic refugia disproportionally, despite their importance for safeguarding present and future biodiversity in the Mediterranean. Key climatic refugia could limit the impacts of future climate change on biodiversity in mid-altitude and mountainous regions, and should be included in management guidelines for a climate-ready conservation design in the Mediterranean biome.

Geodiversity impacts plant community structure in a semi-arid region

Geodiversity refers to the variety of geological and physical elements as well as to geomorphological processes of the earth surface. Heterogeneity of the physical environment has an impact on plant diversity. In recent years, the relations between geodiversity and biodiversity has gained attention in conservation biology, especially in the context of climate change. In this study, we assessed the spatial and temporal change in plant's community structure in a semi-arid region, Sayeret Shaked Long Term Ecosystem Research (LTER) station, Israel. Vegetation surveys were conducted on different hillslopes, either with or without rock covers in order to study the spatial trends of hillslope geodiversity. The surveys were conducted for two consecutive years (2016 and 2017), of which the second year was drier and hotter and therefore permitted to investigate the temporal change of plant's community structure. The results of the spatial trends show that (1) geodiversity increases vegetation biodiversity and promotes perennial plants and those of the temporal change show that (2) the positive effect of geodiversity on plants' community structure and species richness is greater in the drier year than that in a wetter year. The main insight is that in these drylands, hillslopes with higher geodiversity appear to buffer the effect of drier years, and supported a more diverse plant community than lower geodiversity hillslopes.

Climatic, topographic, and anthropogenic factors determine connectivity between current and future climate analogs in North America

As climatic conditions shift in coming decades, persistence of many populations will depend on their ability to colonize habitat newly suitable for their climatic requirements. Opportunities for such range shifts may be limited unless areas that facilitate dispersal under climate change are identified and protected from land uses that impede movement. While many climate adaptation strategies focus on identifying refugia, this study is the first to characterize areas which merit protection for their role in promoting climate connectivity at a continental extent. We identified climate connectivity areas across North America by delineating paths between current climate types and their future analogs that avoided nonanalogous climates, and used centrality metrics to rank the contribution of each location to facilitating dispersal across the landscape. The distribution of connectivity areas was influenced by climatic and topographic factors at multiple spatial scales. Results were robust to uncertainty in the magnitude of future climate change arising from differing emissions scenarios and general circulation models, but sensitive to analysis extent and assumptions concerning dispersal behavior and maximum dispersal distance. Paths were funneled along north-south trending passes and valley systems and away from areas of novel and disappearing climates. Climate connectivity areas, where many potential dispersal paths overlapped, were distinct from refugia and thus poorly captured by many existing conservation strategies. Existing protected areas with high connectivity values were found in southern Mexico, the southwestern US, and western and arctic Canada and Alaska. Ecoregions within the Isthmus of Tehuantepec, Great Plains, eastern temperate forests, high Arctic, and western Canadian Cordillera hold important climate connectivity areas which merit increased conservation focus due to anthropogenic pressures or current low levels of protection. Our coarse-filter climate-type-based results complement and contextualize species-specific analyses and add a missing dimension to climate adaptation planning by identifying landscape features which promote connectivity among refugia.

Using environmental heterogeneity to plan for sea-level rise

Environmental heterogeneity is increasingly being used to select conservation areas that will provide for future biodiversity under a variety of climate scenarios. This approach, termed conserving nature's stage (CNS), assumes environmental features respond to climate change more slowly than biological communities, but will CNS be effective if the stage were to change as rapidly as the climate? We tested the effectiveness of using CNS to select sites in salt marshes for conservation in coastal Georgia (U.S.A.), where environmental features will change rapidly as sea level rises. We calculated species diversity based on distributions of 7 bird species with a variety of niches in Georgia salt marshes. Environmental heterogeneity was assessed across six landscape gradients (e.g., elevation, salinity, and patch area). We used 2 approaches to select sites with high environmental heterogeneity: site complementarity (environmental diversity [ED]) and local environmental heterogeneity (environmental richness [ER]). Sites selected based on ER predicted present-day species diversity better than randomly selected sites (up to an 8.1% improvement), were resilient to areal loss from SLR (1.0% average areal loss by 2050 compared with 0.9% loss of randomly selected sites), and provided habitat to a threatened species (0.63 average occupancy compared with 0.6 average occupancy of randomly selected sites). Sites selected based on ED predicted species diversity no better or worse than random and were not resilient to SLR (2.9% average areal loss by 2050). Despite the discrepancy between the 2 approaches, CNS is a viable strategy for conservation site selection in salt marshes because the ER approach was successful. It has potential for application in other coastal areas where SLR will affect environmental features, but its performance may depend on the magnitude of geological changes caused by SLR. Our results indicate that conservation planners that had heretofore excluded low-lying coasts from CNS planning could include coastal ecosystems in regional conservation strategies.

Scale-dependent complementarity of climatic velocity and environmental diversity for identifying priority areas for conservation under climate change

As most regions of the earth transition to altered climatic conditions, new methods are needed to identify refugia and other areas whose conservation would facilitate persistence of biodiversity under climate change. We compared several common approaches to conservation planning focused on climate resilience over a broad range of ecological settings across North America and evaluated how commonalities in the priority areas identified by different methods varied with regional context and spatial scale. Our results indicate that priority areas based on different environmental diversity metrics differed substantially from each other and from priorities based on spatiotemporal metrics such as climatic velocity. Refugia identified by diversity or velocity metrics were not strongly associated with the current protected area system, suggesting the need for additional conservation measures including protection of refugia. Despite the inherent uncertainties in predicting future climate, we found that variation among climatic velocities derived from different general circulation models and emissions pathways was less than the variation among the suite of environmental diversity metrics. To address uncertainty created by this variation, planners can combine priorities identified by alternative metrics at a single resolution and downweight areas of high variation between metrics. Alternately, coarse-resolution velocity metrics can be combined with fine-resolution diversity metrics in order to leverage the respective strengths of the two groups of metrics as tools for identification of potential macro- and microrefugia that in combination maximize both transient and long-term resilience to climate change. Planners should compare and integrate approaches that span a range of model complexity and spatial scale to match the range of ecological and physical processes influencing persistence of biodiversity and identify a conservation network resilient to threats operating at multiple scales.

Combining geodiversity with climate and topography to account for threatened species richness

Understanding threatened species diversity is important for long-term conservation planning. Geodiversity-the diversity of Earth surface materials, forms, and processes-may be a useful biodiversity surrogate for conservation and have conservation value itself. Geodiversity and species richness relationships have been demonstrated; establishing whether geodiversity relates to threatened species' diversity and distribution pattern is a logical next step for conservation. We used 4 geodiversity variables (rock-type and soil-type richness, geomorphological diversity, and hydrological feature diversity) and 4 climatic and topographic variables to model threatened species diversity across 31 of Finland's national parks. We also analyzed rarity-weighted richness (a measure of site complementarity) of threatened vascular plants, fungi, bryophytes, and all species combined. Our 1-km² resolution data set included 271 threatened species from 16 major taxa. We modeled threatened species richness (raw and rarity weighted) with boosted regression trees. Climatic variables, especially the annual temperature sum above 5 °C, dominated our models, which is consistent with the critical role of temperature in this boreal environment. Geodiversity added significant explanatory power. High geodiversity values were consistently associated with high threatened species richness across taxa. The combined effect of geodiversity variables was even more pronounced in the rarity-weighted richness analyses (except for fungi) than in those for species richness. Geodiversity measures correlated most strongly with species richness (raw and rarity weighted) of threatened vascular plants and bryophytes and were weakest for molluscs, lichens, and mammals. Although simple measures of topography improve biodiversity modeling, our results suggest that geodiversity data relating to geology, landforms, and hydrology are also worth including. This reinforces recent arguments that conserving nature's stage is an important principle in conservation.