Search

Motivation: Freshwater ecosystems have been heavily impacted by land‐use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiple biological groups and geographic locations) across sites with different land‐use categories. This compilation will be useful for addressing questions regarding land‐use change and its impact on freshwater biodiversity. Main Types of Variables Contained: The database includes metadata of each study, sites location, sample methods, sample time, land‐use category and abundance of each taxon. Spatial Location and Grain: The database contains data from across the globe, with 85% of the sites having well‐defined geographical coordinates. Major Taxa and Level of Measurement: The database covers all major freshwater biological groups including algae, macrophytes, zooplankton, macroinvertebrates, fish and amphibians. [ABSTRACT FROM AUTHOR]

Research to inform a sustainable future for southern African mountains as social–ecological systems requires major investment. This is needed to strengthen existing relationships, build new relationships among academia, policy, and practice, and drive a robust research capacity program. This is particularly important in disciplines where there is currently limited capacity for mountain-related research in the region. For many pertinent issues in southern African mountains, the urgent need for foundational research is a reality; without this, it is impossible to build toward multidisciplinary outcomes and to drive transdisciplinary efforts. Keys to strengthening solution-oriented research are improved coordination between actors in similar disciplines (eg water security), strong relationships to achieve maximum synergy instead of competition, and major investment in emerging young researchers. The Afromontane Research Unit is leading the way for southern African mountains. [ABSTRACT FROM AUTHOR]

To exploit the potential of ecological intensification during sunflower cropping, it is crucial to understand the potential synergies between crop management and ecosystem services. We therefore examined the effect of pollination intensification on sunflower yield and productivity under various levels of soil fertilization over two seasons in the eastern Free State, South Africa. We manipulated soil fertility with fertilizer applications and pollination with exclusion bags. We found a synergetic effect between pollination and soil fertilization whereby increasing pollination intensity led to a far higher impact on sunflower yield when the soil had been fertilized. Specifically, the intensification of insect pollination increased seed yield by approximately 0.4 ton/ha on nutrient poor soil and by approximately 1.7 ton/ha on moderately fertilized soil. Our findings suggest that sunflower crops on adequate balanced soil fertility will receive abundant insect pollination and may gain more from both synergies than crops grown in areas with degraded soil fertility. [ABSTRACT FROM AUTHOR]

Gene flow and genetic variation were examined within and among populations of five of the most common spider species in shrublands of the mountainous Golden Gate Highlands National Park (GGHNP), South Africa. These species included three active hunters, Dendryphantes purcelli Peckham & Peckham, 1903 (Salticidae), Pherecydes tuberculatus O.P.-Cambridge, 1883 (Thomisidae) and Philodromus browningi Lawrence, 1952 (Philodromidae), and two web-builders, Neoscona subfusca (C.L. Koch, 1837) (Araneidae) and a Theridion Walckenaer, 1802 species (Theridiidae). A total of 249 spiders (57 D. purcelli, 69 N. subfusca, 34 P. browningi, 56 P. tuberculatus and 33 Theridion sp.) were collected and analysed from six shrubland localities in the park. Analyses of sequence variation of the mitochondrial cytochrome oxidase c subunit I (COI) gene for each species revealed relatively low nucleotide diversity (π < 0.0420) but high genetic diversity (Hd > 0.6500) within populations for all species, except P. tuberculatus. Genetic differentiation was also noted to differ between species, with only P. tuberculatus indicating very large divergence (Fst > 0.2500). These results were reflected by gene flow, with D. purcelli, N. subfusca and the Theridion sp. estimated as experiencing more than one disperser per generation. Overall, highest gene flow was found in the two web-building species, indicating possible high dispersal ability of these spiders in the GGHNP. Additionally, constructed phylogenies indicated possible cryptic speciation occurring in the majority of the investigated species. Our current results indicate that the five investigated spider species were able to maintain gene flow between shrubland populations within the GGHNP to some degree, despite the mountainous landscape. However, further analyses incorporating additional molecular markers are needed to properly determine the extent of genetic diversity and gene flow of these species within the GGHNP. [ABSTRACT FROM AUTHOR]

Achieving sustainable food security is a critical goal for smallholder farmers in mountainous regions around the world. In the 40,000 km2 Maloti–Drakensberg mountains (South Africa and Lesotho), one of the important mountain ranges of southern Africa, farmers are directly dependent on natural resources. Natural resource management is currently unsustainable, driving landscape degradation and entrenching poverty cycles. Through a comprehensive literature review, we explore the current status of knowledge, opportunities, and agriculture-dependent natural resource sustainability in the Maloti–Drakensberg, and outline the priorities for future research in mountain agriculture in southern Africa. The Maloti–Drakensberg has diverse land tenure systems and climatic heterogeneity that together determine farming practices. Agropastoralism is the predominant agricultural practice, occupying 79% of the land, because of the natural grass-dominated vegetation. Despite decades of concern, the sustainable management of communal rangeland remains elusive. Arable cropping is practiced on 12% of the land at subsistence levels, while game farming contributes a small amount to local revenues. A multipronged research approach is needed to understand the complex social–ecological issues around soil degradation and sustainable utilization of the limited agricultural natural resources base. Innovative and adaptive strategies that take into account local and indigenous knowledge, mitigate soil degradation, and enhance water and rangeland conservation are needed to promote sustainable food production in the Maloti–Drakensberg. [ABSTRACT FROM AUTHOR]

Globally, Fusarium root rot, which is caused by Fusarium graminearum, reduces wheat (Triticum aestivum L.) yield and quality up to 20%. Colonization of roots by F. graminearum has been recognized, but controlling Fusarium root rot using worm extracts (mucus, vermicompost tea, and vermiwash) has received little attention. We report the antagonistic properties of redworm (Eisenia fetida) extracts against F. graminearum and their effects on wheat seedling growth. Mycelial growth inhibition against the fungus was conducted in quintuplicate using the extracts in vitro. The extracts significantly inhibited mycelial growth of the fungus under in vitro conditions, and there was significant interaction between the infections and extracts for all the parameters measured (root and shoot lengths, root biomass, and disease index). Redworm mucus and 14-d vermiwash produced moderately (26%) to relatively less (16%) antifungal activity, respectively. Vermiwash and augmented vermicompost tea were able to inhibit Fusarium root rot and improve (>58%) the growth of the inoculated seedlings under laboratory conditions. Vermiwash also acted as nutritional supplement, enhancing plant growth. The extracts suppressed F. graminearum and could serve as a potential bio-fungicide in the integrated management of Fusarium root rot in wheat. Longer term experiments under field conditions are needed to validate the findings from the current study. [ABSTRACT FROM AUTHOR]

We used the Enchytraeid Reproduction Test to evaluate the potential ecotoxic effects of sewage sludge samples on terrestrial oligochaetes in an Afromontane area. The sludge samples were collected from two wastewater treatment plants near the towns of Phuthaditjhaba and Harrismith in the Afromontane region of the eastern Free State in South Africa. Laboratory experiments revealed that although the sludge samples were not detrimental to the survival of Enchytraeus albidus (p > 0.05); they were able to significantly hinder its reproduction (p < 0.01). Through metal analyses, the sludge samples were found to belong to the relatively "best quality" pollutant class a sludge which is deemed suitable for land disposal and use as soil amendment for agricultural purposes. Herein, we point to the fact that the current South African sewage sludge disposal guidelines may not insure the protection of beneficial soil dwelling invertebrates such as oligochaetes. Our contribution also highlights the paucity of studies with an emphasis on environmental pollution in mountain areas across Africa and should signal a need for broader environmental considerations such as environmental pollution to be taken into account in the existing mountain invertebrate conservation methodologies. [ABSTRACT FROM AUTHOR]

The present study investigated the use of biochar for the alleviation of the toxic effects of a nanosilver colloidal dispersion and a chloronicotinyl insecticide. The survival and reproduction of the potworm Enchytraeus albidus were assessed after exposure to imidacloprid and silver nanoparticles (AgNPs). E. albidus was exposed to 0, 25, 50, 100, 200, and 400 mg imidacloprid/kg and 0, 5, 25, 125, and 625 mg Ag/kg for 21 days in 10% biochar amended and non-biochar amended OECD artificial soil. In both exposure substrates, the effects of imidacloprid on survival were significant in the two highest treatments (p < 0.01). No biochar effect was observed as survival was statistically similar in both soils after exposure to imidacloprid. In the case of AgNPs, significant mortality was only observed in the highest AgNP treatments in both the amended and non-amended soils (p < 0.05). Nevertheless, statistically greater survival occurred in the biochar-amended treatment (p < 0.05). Reproduction results showed a more pronounced biochar effect with an EC50 = 22.27 mg imidacloprid/kg in the non-amended soil and a higher EC50 = 46.23 mg imidacloprid/kg in the biochar-amended soil. This indicated a 2-fold decrease in imidacloprid toxicity due to biochar amendment. A similar observation was made in the case of AgNPs where a reproduction EC50 = 166.70 mg Ag/kg soil in the non-amended soil increased to an EC50 > 625 mg Ag/kg soil (the highest AgNP treatment) in the amended soil. This indicated at least a 3.7-fold decrease in AgNPs toxicity due to biochar amendment. Although more studies may be needed to optimize the easing effects of biochar on the toxicity of these chemicals, the present results show that biochar could be useful for the alleviation of the toxic effects of imidacloprid and silver nanoparticles in the soil. [ABSTRACT FROM AUTHOR]

Suitable reservoirs and monitoring methods are needed to manage scarce water supplies in dry countries. We assessed here the impact on aquatic macroinvertebrates of the only dam on the Eerste River, which runs through the heart of a biodiversity hotspot, the Cape Floristic Region, South Africa. The dam and associated activities, were the only forms of disturbance in this otherwise pristine area. We sampled over 20,000 macroinvertebrate individuals and illustrated some categorical effects of the impoundment and its effects on macroinvertebrate assemblages. Macroinvertebrate species diversity below the dam was only half of that in the pristine catchment area above the dam. Furthermore, Ephemeroptera, Plecoptera and Trichoptera diversity and abundance dropped to almost zero as a result of the impoundment. In contrast, the abundance of the Diptera family Chironomidae increased substantially below the dam. These changes in macroinvertebrate diversity mirrored those recorded in biologically less diverse areas, but are of major concern in this biodiversity hotspot with its rich endemic fauna. We conclude that such an impoundment, while important for human welfare, results in a high price being paid in terms of loss of local biodiversity. [ABSTRACT FROM AUTHOR]