| 1. |
- Bashant, Janelle, et al.
(författare)
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Facilitation or Competition? Effects of Lions on Brown Hyaenas and Leopards
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- Intra-guild interactions related to facilitation and competition can be strong forces structuring ecological communities and have been suggested as particularly prominent for large carnivores. The African lion (Panthera leo) is generally thought to be a dominant predator where it occurs and can be expected to have broad effects on sympatric carnivore communities. We used data from two small game reserves in northern South Africa to relate the presence of African lions to abundance, habitat use, diet, and prey selection of two sympatric large carnivores, brown hyaenas (Parahyaena brunnea) and leopards (Panthera pardus). Our results offered some support for the facilitative effects of lions on brown hyaenas, and competitive effects on leopards. However, differences between populations living without and with lions were restricted to broad diet composition and appear not to have permeated into differences in either prey selection, abundance or habitat use. Therefore, we suggest that the potential effects of lions on the predator–prey interactions of sympatric predators may have been context dependent or absent, and subsequently argue that lions may not necessarily influence the predator–prey dynamics in the landscapes they live in beyond those caused by their own predatory behaviour.
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| 2. |
- Blyth, Colette, et al.
(författare)
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Increased Genetic Diversity via Gene Flow Provides Hope for Acacia whibleyana, an Endangered Wattle Facing Extinction
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12:8
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we apply a conservation genomics approach to make evidence-based management recommendations forAcacia whibleyana,an endangered shrub endemic to Eyre Peninsula, South Australia. We used population genomic analysis to assess genetic connectivity, diversity, and historical inbreeding across all known stands of the species sampling remnant stands, revegetated stands of unknown origin, and a post-fire seedling cohort. Our results indicate a degree of historical connectivity across the landscape, but habitat loss and/or pollinator community disruption are potential causes of strong genetic structure across the remnant stands. Remnant stands had low genetic diversity and showed evidence of historical inbreeding, but only low levels of intra-stand relatedness indicating that risks of contemporary inbreeding are low. Analysis of a post-fire first generation cohort of seedlings showed they likely resulted from intra-stand matings, resulting in reduced genetic diversity compared to the parents. However, admixed seedlings in this cohort showed an increase in heterozygosity relative to likely sources and the non-admixed seedlings of the same stand. Assisted inter-stand gene flow may prove an effective management strategy to boost heterozygosity and corresponding increases in adapting capacity in this endangered species.
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| 3. |
- Canelo, Tara, et al.
(författare)
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Effects of Longer Droughts on Holm Oak Quercus ilex L. Acorn Pests : Consequences for Infestation Rates, Seed Biomass and Embryo Survival
- 2021
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- The effects of climate change on oaks Quercus spp. constitute a main environmental concern for the conservation of temperate forests. In this context, we assessed the consequences of longer droughts on the interactions between the holm oak Quercus ilex L. and its main acorn pests. Infested acorns were prematurely abscised before reaching their potential size. The volume of the acorns attacked by Cydia fagiglandana (Lepidoptera) was smaller than those attacked by Curculio elephas (Coleoptera); however, their weight did not differ because Curculio larvae consumed more cotyledon. For the same reason, embryo survival likelihood was not lower in Cydia acorns despite their smaller size. Delays of late summer rain reduced infestation by Curculio, as soil hardness hampers adult emergence from their underground cells. By contrast, late and scarce precipitations benefited Cydia; rainfall might hamper adult flight and eggs/L1 larvae survival. There was not a “zero-sum” effect, because the decrease of Curculio infestation rates was not fully compensated by an increase of Cydia. Under the longer droughts projected for the Mediterranean Basin, our results predict lower infestation rates and higher acorn survival likelihood. However, further studies including other environmental factors are needed to better forecast the net consequences for holm oak fitness.
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| 4. |
- Coulson, Stephen
(författare)
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Diversity and Distribution of Mites (Acari: Ixodida, Mesostigmata, Trombidiformes, Sarcoptiformes) in the Svalbard Archipelago
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Svalbard is a singular region to study biodiversity. Located at a high latitude and geographically isolated, the archipelago possesses widely varying environmental conditions and unique flora and fauna communities. It is also here where particularly rapid environmental changes are occurring, having amongst the fastest increases in mean air temperature in the Arctic. One of the most common and species-rich invertebrate groups in Svalbard is the mites (Acari). We here describe the characteristics of the Svalbard acarofauna, and, as a baseline, an updated inventory of 178 species (one Ixodida, 36 Mesostigmata, 43 Trombidiformes, and 98 Sarcoptiformes) along with their occurrences. In contrast to the Trombidiformes and Sarcoptiformes, which are dominated in Svalbard by species with wide geographical distributions, the Mesostigmata include many Arctic species (39%); it would thus be an interesting future study to determine if mesostigmatid communities are more affected by global warming then other mite groups. A large number of new species (42 spp.) have been described from Svalbard, including 15 that have so far been found exclusively there. It is yet uncertain if any of these latter species are endemic: six are recent findings, the others are old records and, in most cases, impossible to verify. That the Arctic is still insufficiently sampled also limits conclusions concerning endemicity.
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| 5. |
- Eggertsen, Linda, et al.
(författare)
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Seascape Configuration Leads to Spatially Uneven Delivery of Parrotfish Herbivory across a Western Indian Ocean Seascape
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- Spatial configuration of habitat types in multihabitat seascapes influence ecological function through links of biotic and abiotic processes. These connections, for example export of organic matter or fishes as mobile links, define ecosystem functionality across broader spatial scales. Herbivory is an important ecological process linked to ecosystem resilience, but it is not clear how herbivory relates to seascape configuration. We studied how herbivory and bioerosion by 3 species of parrotfish were distributed in a multi-habitat tropical seascape in the Western Indian Ocean (WIO). We surveyed the abundance of three species with different life histories-Leptoscarus vaigiensis (seagrass species), Scarus ghobban (juvenile-seagrass/adults-reefs) and Scarus rubroviolaceus (reef species) -in seagrass meadows and on reefs and recorded their selectivity of feeding substrate in the two habitats. Herbivory rates for L. vaigiensis and S. ghobban and bioerosion for S. rubroviolaceus were then modelled using bite rates for different size classes and abundance and biomass data along seascape gradients (distance to alternative habitat types such as land, mangrove and seagrass). Bioerosion by S. rubroviolaceus was greatest on reefs far from seagrass meadows, while herbivory rates by S. ghobban on reefs displayed the opposite pattern. Herbivory in seagrass meadows was greatest in meadows close to shore, where L. vaigiensis targeted seagrass leaves and S. ghobban the epiphytes growing on them. Our study shows that ecological functions performed by fish are not equally distributed in the seascape and are influenced by fish life history and the spatial configuration of habitats in the seascape. This has implications for the resilience of the system, in terms of spatial heterogeneity of herbivory and bioerosion and should be considered in marine spatial planning and fisheries management.
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| 6. |
- Eggertsen, Maria, et al.
(författare)
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Seascape Configuration and Fine-Scale Habitat Complexity Shape Parrotfish Distribution and Function across a Coral Reef Lagoon
- 2020
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 12:10
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Tidskriftsartikel (refereegranskat)abstract
- Structural complexity spanning fine to broad spatial scales can influence the distribution and activity of key organisms within marine ecosystems. However, the relative importance of hard (e.g., corals) and/or soft (e.g., macroalgae) structural complexity for marine organisms is often unclear. This study shows how both broad-scale (seascape configuration of coral structure) and fine-scale habitat complexity (structure height, number of holes, and presence of macroalgae) can influence the abundance and spatial ecology of reef fish. Underwater visual census of fish, surveys of habitats, remote underwater videos, and behavioral observations by following individual fish were used to quantify fine-scale habitat characteristics (e.g., complexity, coral structure height, macroalgae presence) and the abundance, size structure, and behavior (rates of herbivory, tortuosity ratios and total distance travelled) of abundant parrotfish. Both seascape configuration and macroalgae influenced the patterns of fish abundance and rates of herbivory. However, these relationships varied with trophic groups and ontogenetic stages. Abundance of adult and intermediate-phase parrotfishes was positively influenced by densely aggregated coral structures, whereas juvenile abundance was positively influenced by the presence of macroalgae. Foraging path and bite rates of an abundant parrotfish, Chlorurus spilurus, were not influenced by coral structure configuration or height, but the presence of macroalgae increased the bite rates of all juvenile parrotfish. Our results suggest that a combination of seascape configuration, fine-scale habitat complexity, and microhabitat selectivity influence reef fish community structure and foraging behavior, thus altering herbivory. However, these relationships can differ among functional groups of fish and life-history stages. Information on these fish–habitat interactions is critical for identifying habitats that facilitate ecological functions and ensures the successful management and conservation of essential habitats.
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| 7. |
- Gaytán, Álvaro, et al.
(författare)
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Trees Increase Ant Species Richness and Change Community Composition in Iberian Oak Savannahs
- 2021
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Iberian man-made oak savannahs (so called dehesas) are traditional silvopastoral systems with a high natural value. Scattered trees provide shelter and additional food to livestock (cattle in our study sites), which also makes possible for animals depending on trees in a grass-dominated landscape to be present. We compared dehesas with nearby treeless grasslands to assess the effects of oaks on ant communities. Formica subrufa, a species associated with decayed wood, was by far the most abundant species, especially in savannahs. Taxa specialized in warm habitats were the most common both in dehesas and grasslands, as expected in areas with a Mediterranean climate. Within dehesas, the number of species was higher below oak canopies than outside tree cover. Compared to treeless grasslands, the presence of oaks resulted in a higher species richness of aphid-herding and predator ants, probably because trees offer shelter and resources to predators. The presence of oaks changed also the species composition, which differed between grasslands and dehesas. In self-standing scattered oaks, ant communities did not differ between the trunks and soil below canopies. These results stress the conservation value of trees in dehesas; within grasslands, they offer an additional microhabitat for species that would otherwise be scarce or absent.
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| 8. |
- Grant, Danielle M., et al.
(författare)
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The future of dna barcoding : Reflections from early career researchers
- 2021
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Over the last two decades, the use of DNA barcodes has transformed our ability to identify and assess life on our planet. Both strengths and weaknesses of the method have been exemplified through thousands of peer-reviewed scientific articles. Given the novel sequencing approaches, currently capable of generating millions of reads at low cost, we reflect on the questions: What will the future bring for DNA barcoding? Will identification of species using short, standardized fragments of DNA stand the test of time? We present reflected opinions of early career biodiversity researchers in the form of a SWOT analysis and discuss answers to these questions.
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| 9. |
- Grosse, Maël, et al.
(författare)
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Still Digging: Advances and Perspectives in the Study of the Diversity of Several Sedentarian Annelid Families
- 2021
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Sedentarian annelids are a diverse and heterogeneous group of marine worms representing more than 8600 species gathered in ca. 43 families. The attention brought to these organisms is unevenly distributed among these families, and the knowledge about them sometimes scarce. We review here the current knowledge about the families Acrocirridae, Cirratulidae (including Ctenodrilidae), Cossuridae, Longosomatidae, Paraonidae, and Sternaspidae in terms of biodiversity as well as the evolution of the taxonomy and systematics of each group. We present the challenges faced when studying these organisms and compare methodologies across groups and perspectives in future research.
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| 10. |
- Heingård, Miriam, et al.
(författare)
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New remains of scandiavis Mikkelseni inform avian phylogenetic relationships and brain evolution
- 2021
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Although an increasing number of studies are combining skeletal and neural morphology data in a phylogenetic context, most studies do not include extinct taxa due to the rarity of preserved endocasts. The early Eocene avifauna of the Fur Formation of Denmark presents an excellent opportunity for further study of extinct osteological and endocranial morphology as fossils are often exceptionally preserved in three dimensions. Here, we use X-ray computed tomography to present additional material of the previously described taxon Scandiavis mikkelseni and reassess its phylogenetic placement using a previously published dataset. The new specimen provides novel insights into the osteological morphology and brain anatomy of Scandiavis. The virtual endocast exhibits a morphology comparable to that of modern avian species. Endocranial evaluation shows that it was remarkably similar to that of certain extant Charadriiformes, yet also possessed a novel combination of traits. This may mean that traits previously proposed to be the result of shifts in ecology later in the evolutionary history of Charadriiformes may instead show a more complex distribution in stem Charadriiformes and/or Gruiformes depending on the interrelationships of these important clades. Evaluation of skeletal and endocranial character state changes within a previously published phylogeny confirms both S. mikkelseni and a putative extinct charadriiform, Nahmavis grandei, as charadriiform. Results bolster the likelihood that both taxa are critical fossils for divergence dating and highlight a biogeographic pattern similar to that of Gruiformes.
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