Search Results (6)

The Midlands region of KwaZulu-Natal (KZN) Province in South Africa was hitherto a putative centre of floristic endemism (CFE) based on conjecture. The aim of this study was to empirically explore this concept by delineating unambiguous boundaries for this CFE and documenting the endemic spermatophytes within a conservation framework. The Greater Midlands Centre of Floristic Endemism (GMCFE), a more expanded study area than the parochial Midlands region of KZN, is formally described as southern Africa’s 20th CFE. It is a mid-elevation region occupying the greater Midlands of KZN, with extensions of contiguous grasslands extending northwards into southern Mpumalanga and southwards into north-eastern Eastern Cape. This “foothills” CFE covers ca. 77,000 km² of predominantly mesic C₄ grassland, ranging in elevation from ca. 700–2200 m a.s.l. It is congruent with the “sub-escarpment ecoregion,” essentially a composite of the Sub-escarpment Grassland and Savanna Bioregions and the sub-escarpment grasslands of southern Mpumalanga and northern KZN. The GMCFE hosts at least 220 endemic spermatophytes, of which almost a fifth belong to the family Apocynaceae. Families Asteraceae, Asphodelaceae, Fabaceae, and Iridaceae also contribute significantly. Genera Ceropegia, Aloe, Dierama, Kniphofia, Helichrysum, and Streptocarpus contribute the most endemics. More than half are forbs, and almost three-quarters are confined to the Grassland Biome. Endemic radiations are attributed to geodiversity and geological complexity (especially the strong lithological influence of dolerite); physiographic heterogeneity (particularly elevation gradients and variable terrain units); strategic proximity to hyper-diverse temperate and subtropical “border floras”; and localized pollinator-driven adaptive radiations. Of alarming concern is the high number of threatened plant taxa, with ca. 60% of the endemic flora Red Listed in threat categories (CE, E, and VU) or considered “rare”. Extremely low levels of formal protection and poor ecological connectivity, coupled with high levels of land transformation and intensive utilization, render the GMCFE one of the most imperilled CFE in South Africa. Urgent conservation action is required to safeguard this unique and highly threatened “rangeland flora” and stem the biodiversity crisis gripping the region. Full article

The soil is a component of geodiversity, a geoheritage element providing knowledge of how the geosphere works and interacts with other Earth subsystems. To promote soil as a geoheritage element, we aim to create a geotouristic trail focused on soil, geomorphology, and geoarcheology in the area of Mt. Cusna (Tuscan-Emilian Apennine National Park, Northern Italy), where there is a 20-years long-lasting history of research on geopedology, geoarcheology, and geomorphology. Along existing hiking paths, five soil profiles are identified as sites of potential pedological interest, whereas three more sites are selected to show the geomorphological context of the area and one the geoarcheological evidence. The soil evidence allows for the reconstruction of paleoenvironmental and paleoclimatic conditions, and/or retraction of the human impact that has affected the area over time. In order to communicate the information about the geotouristic trail, illustrative panels were prepared for each trail site and underwent a formative evaluation by students attending academic courses in Natural Sciences to improve the offer. Through the trail, it will be possible to enable the visitor to discover the soil concept, which is often poorly known or even underestimated in its scientific and cultural value. Moreover, the cultural opportunities of the Mt. Cusna geosite will be enhanced. Full article

Non-formal learning can have a crucial role in increasing citizens’ literacy to geoscience providing the opportunity to raise the public profile of geology and geomorphology. Starting from these remarks, the project presented here is one of the first attempts, at national level, aimed at achieving the territorial upgrading based on geoheritage enhancement. The project started thanks to a bottom-up input and involved the collaboration between scholars and local administrations and stakeholders for the valorization of a fluvial area within the Municipality of Castellarano (Emilia Apennines, Northern Italy). To achieve this aim of non-formal learning activities, based on the interpretation of the geoheritage, have been implemented. In fact, the investigated area includes valuable geological and geomorphological features which have been used, in the frame of the project here presented, to promote local geodiversity and geotourism. In particular, three geosites of regional significance were considered for the creation of EarthCaches, interpretative panels and guided excursions. Interpretative contents were designed to be educational, providing accurate but non-technical explanations. Attention was given in including illustrations playing an important role in the learning process. The results revealed that the implemented activities positively contribute to raising public awareness on the value of geoheritage. Full article

Geodiversity integrates physical parameters such as geological, geomorphological, and pedological components. It represents the abiotic diversity of the earth surface layer. It incorporates geological (bedrocks and mineral sediments), geomorphological (geography, land surface formations, physical processes), pedological (soils), and hydrological characteristics. Biological soil crusts (biocrusts) play an essential role in regulating the biogeochemical cycles of carbon and nitrogen. Their ability is dependent on habitat conditions, composition, and cover percentage of the ground surface, all of which are affected by geodiversity. This study’s objective was to assess the effects of geodiversity on the biogeochemical functions of biocrusts by regulating the soil water dynamics and the subsequent impact on readily available nitrogen and carbon. Hillslope geodiversity is determined by the geodiversity found in the stone cover on the ground surface and in the stone content throughout the soil profile, as well as by the soil profile thickness of the underlying bedrock. We hypothesized that in dry environments, the physical conditions in high-geodiversity hillslopes, compared to low-geodiversity hillslopes, positively affect the soil water budget, which would affect the biocrusts and their readily available nitrogen and carbon. The results showed higher soil moisture content in the heterogeneous hillslopes. The ammonium and labile organic carbon in the biocrusts were more substantial in the heterogeneous than in the homogeneous hillslopes, while soil protein, nitrite, and soil organic matter were similar. We suggest that the comparatively high soil moisture content in the heterogeneous hillslopes stimulates biocrust community activities and increases the readily available nitrogen and carbon, thus improving the survival of shrubs in these ecosystems under long-term drought conditions. Full article

In qualitative–quantitative assessment of geodiversity, geomorphology describes landscape forms suggesting specific locations as geosites. However, all digital elevation models (DEM) contain information only about altitude and coordinate systems, which are not enough data for inclusion assessments. To overcome this, researchers may transform altitude parameters into a range of different models such as slope, aspect, plan, and profile curvature. More complex models such as Geomorphon or Topographic Position Index (TPI) may be used to build visualizations of landscapes. All these models are rarely used together, but rather separately for specific purposes—for example, aspect may be used in soil science and agriculture, while slope is considered useful for geology and topography. Therefore, a qualitative–quantitative assessment of geodiversity has been developed to recognize possible geosite locations and simplify their search through field observation and further description. The Coromandel Peninsula have been chosen as an area of study due to landscape diversity formed by Miocene–Pleistocene volcanism which evolved on a basement of Jurassic Greywacke and has become surrounded and partially covered by Quaternary sediments. Hence, this research provides a comparison of six different models for geomorphological assessment. Models are based on DEM with surface irregularities in locations with distinct elevation differences, which can be considered geosites. These models have been separated according to their parameters of representations: numerical value and types of landscape. Numerical value (starting at 0, applied to the area of study) models are based on slope, ruggedness, roughness, and total curvature. Meanwhile, Geomorphon and TPI are landscape parameters, which define different types of relief ranging from stream valleys and hills to mountain ranges. However, using landscape parameters requires additional evaluation, unlike numerical value models. In conclusion, we describe six models used to calculate a range of values which can be used for geodiversity assessment, and to highlight potential geodiversity hotspots. Subsequently, all models are compared with each other to identify differences between them. Finally, we outline the advantages and shortcomings of the models for performing qualitative–quantitative assessments. Full article

In Norway, a landscape map exists which gives the opportunity to collect data in landscape units for further analysis. This study covers parts of Norway and Sweden, so the landscape map was extended into Sweden to form a unified landscape structure. A collection of geological and terrain data within landscape units can serve as a tool to describe the geodiversity profile of the units, study their geographical distribution and analyse similarities and dissimilarities between them. We collected geological and terrain data for an area covering large parts of southern Norway and Sweden. The data were collected as attributes in landscape polygons. The data were then analysed using multivariate techniques (Principle component analyses) where the first four axes of variation were definable. The first axis is a terrain axis, the second a bedrock unit axis, the third a bedrock diversity axis and the fourth a soil/sediment axis. In total, the four gradients answer for 54.9% of the total variation in the material. Links are found between the terrain data and geological units, but these links are relatively weak. The four gradients represent a step-less model of the geodiversity profile of the landscape areas but are dependent on the quality and scale of the input data. Norwegian and Swedish data had to be harmonised in order to be analysed together; however, because of this they ended up having a coarser resolution than desired, both spatially and scientifically. The stepless model was clustered to form 16 geodiversity profile groups for easy comparison and regional overview. The procedure can serve as a baseline for more detailed and field-based studies of geodiversity profiles, and give the opportunity to make analytical maps through simple overlay techniques and to compare areas with each other with respect to their geodiversity profile. This can be carried out both alone and in a wider landscape setting. Full article