Grassy Habitats Research Articles

Australasian sequestrate Fungi 20: Russula scarlatina (Agaricomycetes: Russulales: Russulaceae), a new species from dry grassy woodlands of southeastern Australia

Russula scarlatina sp. nov. is a common sequestrate fungus found in the dry sclerophyll Eucalyptus woodlands of southeastern Australia. Basidiomata are hypogeous or sometimes emergent; they are scarlet in youth and become dark sordid red or brown with advanced age. Historically, this species would have been placed in the genus Gymnomyces, but in light of recent revisions in the taxonomy of sequestrate Russulaceae, we place it in the genus Russula. It is morphologically distinct from other sequestrate species of Russula because of its scarlet peridium and unusual cystidial turf in youth. It has been collected only in dry grassy woodlands and open forest habitats of southeastern Australia.

The foraging potential of the Holocene Cape south coast of South Africa without the Palaeo-Agulhas Plain

The Palaeo-Agulhas Plain formed an important habitat exploited by Pleistocene hunter-gatherer populations during periods of lower sea level. This productive, grassy habitat would have supported numerous large-bodied ungulates accessible to a population of skilled hunters with the right hunting technology. It also provided a potentially rich location for plant food collection, and along its shores a coastline that moved with the rise and fall of sea levels. The rich archaeological and paleontological records of Pleistocene sites along the modern Cape south coast of South Africa, which would have overlooked the Palaeo-Agulhas Plain during Pleistocene times of lower sea level, provides a paleoarchive of this extinct ecosystem. In this paper, we present a first order illustration of the “palaeoscape modeling” approach advocated by Marean et al. (2015). We use a resourcescape model created from modern studies of habitat productivity without the Palaeo-Agulhas Plain. This is equivalent to predominant Holocene conditions before recent landscape modifications for farming. We then run an agent-based model of the human foraging system to investigate several research questions. Our agent-based approach uses the theoretical framework of optimal foraging theory to model human foraging decisions designed to optimize the net caloric gains within a complex landscape of spatially and temporally variable resources. We find that during the high sea-levels of MIS 5e (+5–6 m asl) and the Holocene, the absence of the Plain left a relatively poor food base supporting a much smaller population relying heavily on edible plant resources from the current Cape flora. Despite high species diversity of plants with edible storage organs, and marine invertebrates, encounter rates with highly profitable resources were low. We demonstrate that without the Palaeo-Agulhas Plain, human populations must have been small and low-density, and exploited plant, mammal, and marine resources with relatively low caloric returns. The exposure and contraction of the Palaeo-Agulhas Plain was likely the single biggest driver of behavioural change during periods of climate change through the Pleistocene and into the transition to the Holocene.

The contribution of fire to the late Miocene spread of grasslands in eastern Eurasia (Black Sea region)

Grasslands are globally extensive, but the processes governing their ecology and evolution remain unclear. The role of fire for the expansion of ancestral C3 grasslands is particularly poorly understood. Here we present the first biomass combustion record based on late Miocene to Pleistocene (~10–1.9 Ma) charcoal morphologies (grass, herbs, wood) from the Black Sea, and test the extent of fire events and their role in the rise of open grassy habitats in eastern Eurasia. We show that a mixed regime of surface and crown fires under progressively colder and, at times, drier climates from the late Miocene to Pliocene (8.5–4.6 Ma) accelerated the forest to open woodland transition and sustained a more flammable ecosystem. A tipping point in the fire regime occurred at 4.3 Ma (mid-Pliocene), when increasingly cold and dry conditions led to the dominance of grasslands, and surface, litter fires of low intensity. We provide alternative mechanisms of C3 plant evolution by highlighting that fire has been a significant ecological agent for Eurasian grasslands. This study opens a new direction of research into grassland evolutionary histories that can be tested with fossil records of fire alongside climate and vegetation as well as with dynamic vegetation modells.

Wastelands: their attractiveness and importance for preserving the diversity of wild bees in urban areas

Urban wastelands are important substitute habitats for many insect species, but their value for the protection of wild bees is still poorly studied. We assessed species richness, abundance, and the diversity of wild bees in wastelands that differed in area (2–35 ha), stage of ecological succession, location (suburbs or closer to the city centre), and history of land use. In the investigated plots, we recorded 42% of all bee species reported from Poland. The attractiveness of wastelands was positively correlated with the coverage of blooming herbs, coverage of shrubs and low trees, and the area of the wasteland. An increase in isolation of the habitat patches, the percentage contribution of alien species, annuals, and low grasses (< 25 cm) negatively affected the diversity of Apiformes. Considering the history of land use, we found that the bees were most attracted to wastelands resulting from extractive industry (sand and clay pits), and grassy habitats located in the suburbs, e.g. at sites grazed earlier by sheep. Wastelands in areas directly influenced by the chemical industry were the least attractive to bees. Analyses of quantitative and qualitative similarity of bees in various habitat types showed that three habitat types were the most similar to grasslands in the suburbs (the least disturbed habitats): degraded grasslands located closer to the city centre, extraction pits, and old fields. The presented results indicate that urban wastelands, including some post-industrial sites, can be important secondary habitats for wild bees. Thus, proper management of urban natural resources should cover both the formally managed areas and the so-called unproductive spaces, which have been undervalued so far.

Paleoecological implications of dental mesowear and hypsodonty in fossil ungulates from Kanapoi

The Pliocene site of Kanapoi is key to our understanding of the environmental context of the earliest species of Australopithecus. Various approaches have been used to reconstruct the environments of this site, and here we contribute new data and analyses using mesowear and hypsodonty. The dental traits of 98 bovids, suids and rhinocerotids from Kanapoi were analyzed using these proxies. Results indicate that most of the animals analyzed had a relatively abrasive diet. Bovids in the assemblage incorporated more grass into their diet than do modern species of the same tribe or genus. Although Pliocene Kanapoi likely had complex environments, our analysis indicates that grassy habitats were a dominant component of the ecosystem, a conclusion that supports the results of previous investigations of the paleoecology of the site.

Genetic analysis reveals Finnish Formica fennica populations do not form a separate genetic entity from F. exsecta.

Coptoformica Müller, 1923 is a subgenus of Formica Linnaeus, 1758 that consists of c. a dozen species of ants that typically inhabit open grassy habitats and build small nest mounds. The most recent addition to the group is Formica fennica Seifert, 2000. The description was based on morphological characters, but the species status has not been confirmed by molecular methods. In this study, we use thirteen DNA microsatellite markers and a partial mitochondrial COI gene sequence to assess the species status of F. fennica, by comparing the genetic variation among samples identified as F. fennica and six other boreal Formica (Coptoformica) species. Most of the species studied form separate, discontinuous clusters in phylogenetic and spatial analyses with only little intraspecific genetic variation. However, both nuclear and mitochondrial markers fail to separate the species pair F. exsecta Nylander, 1846 and F. fennica despite established morphological differences. The genetic variation within the F. exsecta/fennica group is extensive, but reflects spatial rather than morphological differences. Finnish F. fennica populations studied so far should not be considered a separate species, but merely a morph of F. exsecta.

Emergence of Grassy Habitats during the Greenhouse–Icehouse Systems Transition in the Middle Eocene of Southern South America

Phytolith assemblages recovered from the middle Eocene Koluel-Kaike Formation in Central Patagonia, southern South America, confirm the presence of herbaceous components, mainly related to mixed ecosystems or savannahs, and subordinate dry forest communities. This new palaeobotanical information reveals a clear transition between previously described subtropical/tropical woodland-dominated communities from the early Eocene Las Flores Formation, and grass-rich ecosystems from the mid-Eocene Sarmiento Formation. Saddle phytoliths recorded in the Koluel-Kaike Formation would attest the presence of C4 grasses (Chloridoideae) by the middle Eocene of Central Patagonia. These saddle phytoliths is the oldest grassy habits recorded in Central Patagonia, and preceding in at least ∼8 Ma the timing proposed by previous contributions. The early appearance of grass-dominated ecosystems in southern South America, would be related to the worldwide greenhouse to icehouse systems transition initiated during the mid-Paleogene.

Grassy patch size and structure are important for northern Eastern Bristlebird persistence in a dynamic ecosystem

ABSTRACTReintroductions are a critical tool for threatened species’ conservation, and their success will depend on correctly identifying the key habitat requirements needed for persistence. The Critically Endangered, isolated northern population of the Eastern Bristlebird has declined to an estimated 40 individuals. A successful captive breeding programme means that future reintroductions are likely; however, knowledge of fine-scale habitat requirements associated with persistence is limited. To inform reintroduction efforts we compared habitat attributes of currently occupied and historically occupied habitat patches. Persistence was highly dependent on the extent of contiguous grassy habitat, with larger patches more likely to contain bristlebirds. This association was contingent on grass structure, with less chance of bristlebirds occurring at large sites lacking a tall, thick grassy understorey. Topographic and environmental heterogeneity within large habitat patches likely allows unburnt habitat to persist following fire, increases the temporal availability of prey and allows persistence of a population. For a largely ground-dwelling species, the presence of tall, thick grasses is expected to provide important shelter for foraging and nesting activities. Use of appropriate fire to maintain large contiguous patches with a thick, tall grassy ground layer will be critical for the continued persistence and successful reintroduction of the northern Eastern Bristlebird.

The sclerophyllous wetlands on quartzite substrates in South Africa: Floristic description, classification and explanatory environmental factors

A description of wetland habitats on nutrient-poor sandstone and quartzite substrates across South Africa is given. Most of these are situated in the Fynbos Biome and are dominated by sclerophyllous shrubs but there are some sedge-dominated vegetation types as well as geographical outliers found in Pondoland, the Kamiesberg, the Mpumalanga escarpment, the Soutpansberg and the Waterberg. A subset from a national survey of wetland vegetation was selected for analysis in terms of classification and ordination. This resulted in a classification of 27 communities which are summarized in eight community groups. The variation in the dataset can be largely differentiated by means of altitude and cations and the associated ordination separates a small number of plots belonging to communities that are also distributed outside of the Fynbos Biome from the rest of the dataset. Within the Fynbos Biome, there are different wetland vegetation types found on steep slopes, with shallow soils and a high sand content versus the valley bottoms with deeper soils and a higher silt and clay content. There are also small differences in the nutrient status of different communities. This research showed that wetland plant communities in nutrient-poor communities have a distinct species composition. Species originate from a diverse range of functional types and phylogenetic groups compared to the typical wetland vegetation found in nutrient-rich grassy habitats in the rest of the continent.

Butterfly dispersal in farmland: a replicated landscape genetics study on the meadow brown butterfly (Maniola jurtina)

Anthropogenic activities readily result in the fragmentation of habitats such that species persistence increasingly depends on their ability to disperse. However, landscape features that enhance or limit individual dispersal are often poorly understood. Landscape genetics has recently provided innovative solutions to evaluate landscape resistance to dispersal. We studied the dispersal of the common meadow brown butterfly, Maniola jurtina, in agricultural landscapes, using a replicated study design and rigorous statistical analyses. Based on existing behavioral and life history research, we hypothesized that the meadow brown would preferentially disperse through its preferred grassy habitats (meadows and road verges) and avoid dispersing through woodlands and the agricultural matrix. Samples were collected in 18 study landscapes of 5 × 5 km in three contrasting agricultural French regions. Using circuit theory, least cost path and transect-based methods, we analyzed the effect of the landscape on gene flow separately for each sex. Analysis of 1681 samples with 6 microsatellites loci revealed that landscape features weakly influence meadow brown butterfly gene flow. Gene flow in both sexes appeared to be weakly limited by forests and arable lands, whereas grasslands and grassy linear elements (road verges) were more likely to enhance gene flow. Our results are consistent with the hypothesis of greater dispersal through landscape elements that are most similar to suitable habitat. Our spatially replicated landscape genetics study allowed us to detect subtle landscape effects on butterfly gene flow, and these findings were reinforced by consistent results across analytical methods.

Effects of habitat and landscape features on grassland Orthoptera on floodplains in the lower reaches of the Tisza River Basin

The Tisza River Basin is an important area as it is a green corridor in which there are highly endangered habitats and a high level of biodiversity. The patterns in the species richness of invertebrates and the environmental conditions affecting these patterns are poorly studied in the grassy habitats in the lower reaches of the Tisza River Basin. The present study focuses on the effects of flooding, habitat and landscape features on the species richness of orthopterans at 24 grassland sites in two different landscapes. The relations between the explanatory variables and the pattern of diversity of orthopterans with different life-history traits were studied, using ordination and Generalized Linear Mixed Models. Although the influential factors for the different trait groups differed, we suggest that landscape features are the most important in shaping orthopteran assemblages, whereas habitat characteristics and flooding have comparatively little effect. Habitat characteristics affected only the non-xerophilous and Ensifera species and only the species richness of non-xerophilous orthopterans in flooded and non-flooded sites differed. We emphasize that even in countries where there are still considerable areas of high value natural grasslands, such as Hungary, non-protected meadows, linear grassy habitats (dikes, ditch banks, road verges, etc.) need more attention and should be given higher priority in the conservation of invertebrates.

Birds of a feather flock together: Using trait-groups to understand the effect of macropod grazing on birds in grassy habitats

Restoration of appropriate disturbance regimes is a high conservation priority. However, for most species, little is known about appropriate disturbance regimes to achieve defined conservation outcomes. In this context, trait-based approaches can offer a means to generalize responses to environmental change across multiple species. Here, we investigated the potential of a trait-based approach to predict the preference of birds utilizing the grassy layers for different levels of grazing by a native grazer within grassy habitats in south-eastern Australia. We tested three hypotheses: 1) birds with particular traits (i.e. large ground-foraging, small ground-foraging, aerial insectivore, and ground-nesting/concealment) will show preferences for certain levels of grazing: 2) species within the same trait group will show preferences for a similar level of grazing intensity: and 3) different bird trait groups will favor different grazing intensities Overall, we found a significant relationship between grazing intensity and the richness of aerial insectivore and large ground-foraging trait groups utilizing the grassy layer, but not for the richness of small ground-foraging and ground-nesting/concealment trait groups. We also found that the likelihood of 3/3 aerial insectivores, 4/7 large ground-foragers, 3/10 small ground-foragers, and 1/3 ground-nesting/concealment species using the grassy layer was significantly related to grazing intensity. However, we found no significant relationship between the probability of 12 species using the grassy layer and grazing intensity, with other environmental factors potentially masking grazing response. Importantly, species within the same trait group showed a preference for similar grazing intensities, and different trait groups showed preference for different grazing intensities. For example, aerial insectivores, and a single ground-nesting/concealment species were more likely to use the grassy layer at lower grazing intensities, whereas large ground-foraging birds and small ground-foraging birds were more likely to use the grassy layer at higher grazing intensities. To maintain optimal grass structure for birds with varying grass structure preferences, landscapes should contain a heterogeneous mosaic of grazing intensities.

Influence of diet in the accumulation of organochlorine compounds in herons breeding in remote riverine environments

The composition of organochlorine compounds (OCs), pentachlorobenzene (PeCB), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), DDTs and polychlorobiphenyls (PCBs), has been analyzed in eggs from cattle egret (Bubulcus ibis) and little egret (Egretta garzetta), two species of herons (family Ardeidae), nesting at the same remote riverine environment (Aiguabarreig, Ebro River). These two species were selected to evaluate the importance of diet in the accumulation of OCs. Cattle egret essentially feeds on dry grassy habitats and follow cattle or other large animals whereas little egret feeds on fish, amphibians and crustaceans captured in shallow waters. The δ(15)N and δ(13)C isotopic composition of the sampled eggs was studied and the results were consistent with these species feeding habits. In both species, the compounds accumulated the most were the less volatile and more lipophilic, e.g. PCB congeners of higher chlorination, DDT and metabolites. The distinct foraging species preferences were reflected in significant higher concentrations in little egret than cattle egret of all pollutant groups analysed. These differences were statistically significant for DDTs and PCBs (p < 0.015 and p < 0.047, respectively), e.g. the p,p'-DDE and PCB concentrations were 6 and 4.5 times higher, respectively, in the former than the latter. This strong contrast indicates that in remote environments aquatic riverine ecosystems are more efficient OC reservoirs than the terrestrial ecosystem.

A long-lasting taxonomic problem in European Sympycnus resolved, with the description of a new species and data on habitat preferences.

Type specimens of Sympycnus pulicarius, S. annulipes, S. cinerellus and S. desoutteri were examined to clear up a long-lasting taxonomic confusion. Our study revealed that they represent, together with S. pygmaeus and S. annulipes var. brunnitibialis, a single species, with S. pulicarius as the senior subjective synonym, which is redescribed in this paper. Lectotypes were designated for Dolichopus pulicarius, Porphyrops annulipes, Chrysotus cinerellus and Sympycnus desoutteri. The postpedicel in this species shows substantial variation in shape and size, but the presence of a posteroventral bristle on the mid tibia is more reliable and the particular chaetotaxy and relative lengths of the tarsomeres of the male hind tarsus are entirely consistent. Both latter features separate S. pulicarius from another species, S. septentrionalis sp. nov., that is described here. Ecological data on both species were examined. An analysis of Malaise trap and white pan trap samples collected in Belgium revealed that S. pulicarius is most common in the western part of Flanders, and most abundant in open grassy habitats. In contrast to S. pulicarius, which is widespread over Europe, S. septentrionalis sp. nov. seems confined to northern Europe, where it exhibits a similar habitat preference.

Habitat changes and changing predatory habits in North American fossil canids

The spread of open grassy habitats and the evolution of long-legged herbivorous mammals with high-crowned cheek teeth have been viewed as an example of coevolution. Previous studies indicate that specialized predatory techniques in carnivores do not correlate with the spread of open habitats in North America. Here we analyse new data on elbow-joint shape for North American canids over the past ∼37 million years and show that incipiently specialized species first appeared along with the initial spread of open habitats in the late Oligocene. Elbow-joint morphologies indicative of the behavior of modern pounce-pursuit predators emerged by the late Miocene coincident with a shift in plant communities from C3 to C4 grasses. Finally, pursuit canids first emerged during the Pleistocene. Our results indicate that climate change and its impact on vegetation and habitat structure can be critical for the emergence of ecological innovations and can alter the direction of lineage evolution.

A preliminary study on butterflies of the Kathlaur-Kaushlian Wildlife Sanctuary, Pathankot, Punjab, India

A preliminary study of the butterfly diversity of the Kathlaur-Kaushlian Wildlife Sanctuary (Pathankot, Punjab) India was conducted from 10–11 November 2011. A total of 40 species belonging to 31 genera was recorded, including Libythea myrrha sanguinalis Fruhstorfer, a new species added to the butterfly fauna of Punjab. Species richness was greatest for the family Nymphalidae, with 22 species, followed by Pieridae with 10 species, Lycaenidae with four, and Papilionidae and Hesperiidae with two each. An analysis of relative abundances revealed that of the 40 species reported, 19 were classed as common, 15 as less common and the remaining six species as uncommon. Observations on their occurrence in different habitats revealed 13 species prefer scrubby habitat, 13 scrubby and grassy habitat, seven grassy habitats and the remaining seven scrubby and riverine habitats.

Mosaic of grasslands and woodlands is more effective than habitat connectivity to conserve butterflies in French farmland

In agricultural landscapes, permanent grassy habitats are often fragmented and partly composed of linear elements. Landscape-level connectivity of both grassland patches and grassy linear elements actively contributes to biodiversity conservation in farmland. Nevertheless, their respective importance has rarely been tested. Butterflies form a suitable model group for this purpose; they have suffered a major overall decline in the last few decades and are known to be sensitive to landscape connectivity.We sampled 286 transects nested in 18 study landscapes in three regions. Using several metrics, we analyzed the response of butterflies to the connectivity to both grassland and woodland habitats, which may provide additional resources. The response to landscape connectivity appeared to depend on the type of the semi-natural elements (patch vs linear elements), and on species traits, i.e. the response was stronger for habitat specialists and species with low dispersal ability. We found that woody habitats close to grassland patches had a significant positive effect on butterfly communities, denoting potential mechanisms of resources supplementation and complementation. In grassy linear elements, butterfly communities were of lower conservation value, richness and abundance were much lower (−26 and −50%) than in grassland patches and decreased with isolation from grasslands, in line with the source–sink hypothesis.Although grassy linear elements probably play an important role in butterfly dispersal in agricultural landscapes, they may not be sufficient to preserve specialist and sedentary species. Conserving a mosaic of high quality grassland patches and woody habitats appears more effective than enhancing connectivity.

Spider assemblages within greenspaces of a deindustrialized urban landscape

Many Midwestern cities in the United States have experienced high levels of economic decline and population loss. This deindustrialization has led to thousands of acres of vacant land maintained as grassy habitats. The communities living within these neighborhoods have conceptualized reutilization strategies for this land, including urban agriculture and the creation of small parks of native plantings. In this 2-year study, we examined the impacts of vacant land conversion on spiders within residential vacant lots, community gardens, and planted prairies within the peri-urban park system. At the time of the study, planted prairies on previously vacant land were not common, so those within the park system may serve as a foundation for future plantings. We found that maintained vacant lots contained the most numerous spider assemblages, which was dominated by disturbance-tolerant habitat generalist species. Community gardens contained numerically fewer spiders but a slightly richer assemblage than vacant lots. Similarly low numbers were also found in planted prairies but the assemblage was the most diverse of the greenspaces examined. We also contrasted results at the family versus genus level in order to assess the taxonomic sufficiency relevant for future studies, and found that genus level was important for elucidating the effects of urban land use on these spider assemblages. From this research, we conclude that spiders are an important indicator group of disturbance when examining urban greenspace management and revitalization, and that alteration in greenspace design will influence biodiversity and assemblage composition.

Host preference and offspring performance are linked in three congeneric hyperparasitoid species

1. The optimisation theory predicts that insect mothers should oviposit on resources on which they attain the highest exclusive fitness. The development of parasitoid wasps is dependent on limited host resources that are often not much larger than the adult parasitoid.2. In the present study preference and development in three congeneric species of secondary hyperparasitoids attacking cocoons of two congeneric primary parasitoids that differ significantly in size were compared. Gelis agilis (Fabricius) and G. acarorum (L.) are wingless hyperparasitoids that forage in grassy habitats, whereas G. areator (Panzer) is fully winged and forages higher in the canopy of forbs.3. The three species were reared on cocoons containing pupae of a small gregarious endoparasitoid, Cotesia glomerata (L.), and a larger solitary species, C. rubecula (Marshall), both of which develop in the caterpillars of pierid butterflies.4. Adult mass was correlated with initial cocoon mass in all three species, whereas development time was unaffected. Wasps were larger when developing in C. rubecula. However, for a given host mass, wasps were larger when developing on the smaller host, C. glomerata. This suggests that there is a physiological limit to hyperparasitoid size that was exceeded when C. rubecula served as host.5. All three hyperparasitoids strongly preferred to attack cocoons of the larger species, C. rubecula, often avoiding cocoons of C. glomerata entirely.6. Preference and performance are correlated in the three Gelis species. However, owing to variation in the distribution and thus abundance of their hosts, it is argued that cumulative fitness may be still higher in the smaller host species.

Inicio del enfriamiento global del eoceno medio y expansión de ambientes con vegetación abierta en la patagonia central.

Climate-driven changes in terrestrial environments and biomes after the Early Eocene Climatic Optimum are poorly documented from southern continents. Particularly, Middle Eocene-Early Oligocene leaf and pollen data from Central Patagonia (46oS, Argentina) are not sufficient to characterize floristic paleocommunities. Paleosols of the Ca&ntilde;ad&oacute;n Vaca (~45-42 Ma) and Gran Barranca (42-38.5 Ma) members (Sarmiento Formation), studied at Ca&ntilde;ad&oacute;n Vaca, solve such deficiency and help to reconstruct Middle Eocene landscapes in the beginning of the Cenozoic cooling-drying trend. Vitric Entisols, mollic Andisols and andic Alfisols, showing granular structure and diverse micropeds, are cyclically arranged mainly in response to variation in fine volcaniclastic eolian supply, which in turn governed ecosystem stability and maturity. Soils formed in loessic plains crossed by minor ephemeral rivers, supported open herbaceous-arboreal communities which grew in seasonal, subhumid and warmtemperate conditions. Phytoliths produced by Arecaceae, megathermic graminoids, sedges and dicots, from the upper part of the studied unit, represent subtropical savannas with grasses and variable number of palms and other trees. Considering the abundant paleobotanical and paleopedological antecedents of Late Paleocene-Early Eocene warm and humid forested environments in the same region, the lower Sarmiento Formation records the initial expansion of open herbaceous communities and the appearance of grassy habitats during the greenhouse to icehouse transition in the Middle Eocene.