Vegetation Habitat Research Articles

A new data‐driven riparian revegetation design method

AbstractHydrologic and physical gradients influence vegetation zonation and can form the basis of riparian revegetation design. We present a new data‐driven method to develop riparian revegetation designs by relating the ground height above river (HAR) or a low streamflow water surface as a groundwater proxy to existing vegetation cover types and applying those relationships to design conditions. Steps in the process are as follows: (1) map existing vegetation within the riparian corridor; (2) construct existing and design topographic and groundwater digital elevation models (DEMs), and then difference those DEMs to create a HAR detrended DEM (HAR dtDEM); (3) define existing vegetation habitat zones using the relationship between existing HAR dtDEM and mapped vegetation cover types; (4) apply habitat zone boundaries to detrended design topography; and (5) develop planting schematics using habitat zones and detrended design topography. We developed a revegetation design for a rehabilitation site on the Trinity River, California, using the HAR dtDEM method. We used a data‐driven method to define five habitat zones in riparian areas: aquatic, emergent margin, mesic, mesic–xeric transition, and xeric zones. Zonal boundaries were identified using four criteria: (1) capillary fringe elevation above the low flow water surface, (2) shifts from herbaceous to woody‐dominated cover types, (3) a difference equal to or >0.5 m between two adjacent ranked cover types, and (4) locations where a linear trendline intersected median HAR values or where a group of regression residuals changed from positive to negative or vice versa. The capillary fringe height was the most effective method when determining vegetation zones near the channel. The shift between herbaceous and woody‐dominated cover types defined the boundary between the emergent margin and mesic zone. Elevation increases >0.5 m between adjacent ranked cover types defined the upper and lower mesic–xeric transition zone boundaries best. Comparing linear residuals was most useful for separating drier cover types occurring on higher ground surfaces. Existing habitat zone boundaries were applied to detrended design topography to direct which selected native plant species could be arranged within habitat zones to improve planting survival and increase ecological function following rehabilitation.

Submerged aquatic vegetation habitat use of age-0 Florida bass Micropterus floridanus

Submerged aquatic vegetation habitat use of age-0 Florida bass Micropterus floridanus

The 100,000\u201377,000-Year Old Middle Stone Age Micromammal Sequence from Blombos Cave, South Africa: Local Climatic Stability or a Tale of Predator Bias?

In this paper, we present a case study of the micromammal sequence from Marine Isotope Stage 5 (130,000–71,000 YBP) at Blombos Cave on the southern Cape coast of South Africa. Our analyses of the micromammal assemblage from 100,000 to 76,000 YBP shed light on micromammal taxonomic distributions, local palaeoenvironments, and site formation processes at this renowned Middle Stone Age site. Taphonomic analyses indicate that spotted eagle owls (Bubo africanus) were the main predator species responsible for accumulating the micromammals, but with contributions from barn owls (Tyto alba). In addition, the micromammal bones have been subjected to a range of post-depositional processes, some of which are associated with microbial actions likely resulting from human or animal activities in the cave. We have recorded three species in the archaeological assemblage that do not occur in the Blombos area today. These are the Hottentot golden mole (Amblysomus hottentotus), Duthie’s golden mole (Chlorotalpa duthieae), and Laminate vlei rat (Otomys laminatus). The biodiversity indices based on micromammal species suggest that local vegetation consisted of different habitats that could sustain a diverse small mammal population. During MIS 5c/5b, the diversity of species declined, but there was still a mosaic of vegetation habitats present in the local area. On a larger temporal scale, climate conditions were slightly more humid than at present, and winter rainfall was seemingly greater. The amount of winter rainfall would have been similar to locations currently c. 50–150 km further west of Blombos Cave. However, based on micromammal proxies, there were seemingly no major fluctuations visible in climate or vegetation composition during the entire 24,000-year period. We suggest that the explanation could be multifaceted, two potential factors being predator bias derived from the owls’ preference for generalist micromammal species or an actual reflection of local stable climatic and environmental conditions in the Blombos area.

Benchmarking plant diversity of Palaearctic grasslands and other open habitats

AbstractAimsUnderstanding fine‐grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine‐grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups).LocationPalaearctic biogeographic realm.MethodsWe used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class.ResultsPatterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi‐natural) grasslands and natural grasslands are the richest vegetation type. The open‐access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats.ConclusionsThe GrassPlot Diversity Benchmarks provide high‐quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation‐plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology.

Food-web comparisons between two shallow vegetated habitat types in the Baltic Sea

Coastal vegetated habitats maintain highly diverse communities, where the contribution of macrophyte production is significant for macroinvertebrate primary consumers. In the brackish-waters of the Baltic Sea, the taxonomical diversity of different macrophytes includes both marine and limnic species. To study the basal food-web differences of two key vegetated habitat types, either dominated by a perennial brown macroalgae (Fucus vesiculosus) or by angiosperm plants, 13C and 15N compositions of different primary producers and macroinvertebrate consumers were examined, and their diets were estimated by Bayesian mixing models. Carbon isotope diversity of primary producers was high especially in the hard-bottom Fucus-dominated habitats, which was also reflected in a larger consumer isotope niche. However, consumer isotope niche among sites was similar within the same habitat type. Our models indicated that the perennial macrophyte dietary median contribution was about 25% for deposit feeders and omnivores in both habitat types, while epigrazers preferred filamentous algae (30–60%). The niche positions of the abundant clams L. balthica, M. arenaria and C. glaucum differed between the two habitats, but they showed only small (<10% units) differences in their macrophyte dietary contributions. The isotopic compositions of the dominating primary producer assemblage reflected significantly in the isotope niche structure of the associated primary consumers.

Responses of small mammals to habitat characteristics in Southern Carpathian forests

Compared to Northern Carpathians, the small mammal fauna of Southern Carpathian forests is poorly known, with no data on habitat use; our study seeks to fill this gap. To this end, we conducted a survey in the Southern Carpathians for five years, assessing habitat use by small mammals in forests along an elevational gradient. Trapping was done using live traps set in transects at elevations between 820 and 2040 m. For each transect we evaluated variables related to vegetation structure, habitat complexity, and geographical location. We considered abundance, species composition and species richness as response variables. The rodents Apodemus flavicollis and Myodes glareolus and the shrew Sorex araneus were common and dominant. Their abundance were positively correlated with tree cover, the best explanatory variable. Responses to other variables were mixed. The strong divergence in the relative habitat use by the three most abundant species may act as a mechanism that enables their coexistence as dominant species, exploiting the same wide range of habitat resources. Overall, habitat use in our study area was similar to that reported from Northern Carpathians, but we found also important differences probably caused by the differences in latitude and forest management practices.

The environmental implications of upper Paleozoic plant-fossil assemblages with mixtures of wetland and drought-tolerant taxa in tropical Pangea

We evaluate the influences of elevation and climate on the spatio-temporal distribution of wetland and dryland biomes during the Pennsylvanian and early Permian in tropical Pangea. The longstanding “upland model” places drought-tolerant vegetation in elevated habitats, where slope and drainage created moisture-limited substrates under a humid climate that simultaneously promoted peat accumulation in contemporaneous lowlands. Upland plants were periodically transported to, and buried in, lowlands. Rare preservation of dryland vegetation thus reflects its general absence in basins, and taphonomic vagaries of long-distance transport. The alternative “climate model” proposes that drought-tolerant plants dominated tropical habitats when climate was seasonally dry, with wetland vegetation reduced to scattered refugia. Environmental changes attending glacial-interglacial cycles caused alternating wetter-drier conditions, and the relative abundance of wetland versus dryland biomes in basinal lowlands thus varied with climatic oscillations. The paucity of drought-tolerant plants reflects a preservational megabias against habitats with seasonal moisture deficits.The environmental signal of “mixed” plant-fossil assemblages, comprising taxa characteristic of both wetland and dryland biomes, may help resolve these debates. We review key Pennsylvanian and lower Permian mixed assemblages from tropical Euramerican Pangea, and interpret their original habitats and climatic contexts based on multidisciplinary lines of evidence, including sedimentology, taphonomy, physiology, and paleoecology. Evaluations also consider patterns of vegetational distribution and taphonomy in modern tropical environments. We suggest that even a cursory view of current tropical plant distribution exposes flaws in the upland model. Where tropical climate is sufficiently humid to support peat swamps, slopes and elevated habitats do not host drought-tolerant vegetation, but are occupied by plants similar to those in lowland settings. This occurs because equable, high precipitation strongly dampens water-table variation across entire landscapes. Furthermore, taphonomic studies indicate that most plant-fossil assemblages record vegetation living near the burial site. Fossil floras thus reflect environmental conditions near their growth site, excluding an upland origin for most occurrences of drought-tolerant taxa. Conversely, the climate model is consistent with modern tropical vegetational distribution and soundly explains late Paleozoic floristic patterns. When Pangean tropical lowlands experienced seasonally dry conditions, plants tolerant of moisture deficits dominated most habitats, whereas wetland vegetation was restricted to wetter sites with greater preservation potential. This occurred because topographic variations are magnified under seasonal precipitation regimes, creating a complex habitat mosaic with wetland patches in a landscape subject to seasonal drought. Accordingly, we propose that a macrofloral assemblage with even rare drought-tolerant taxa indicates seasonality in the broader landscape.At larger spatio-temporal scales, disagreement also persists about whether tectonic uplift or long-term climatic drying was the primary driver of changes in late Paleozoic floristic patterns and areal extent of tropical peat swamps. We argue that tectonic activity alone cannot explain the drastic reduction in peat swamps or coincident changes in dominance-diversity of wetland vegetation. Rates of plant dispersal and evolution far outpace that of mountain building, and peat-forming wetlands persisted in elevated habitats well into the Late Pennsylvanian. Therefore, progressive late Paleozoic aridification was the most probable driver of changing floral patterns and the distribution of wetland and dryland biomes in tropical Pangea.

Daya Tarik Keanekaragaman Burung di Jalur Hijau Jalan Kota Yogyakarta

Urban greenery plays an important role in providing a biodiversity habitat of vegetation and birds as biotics in the urban ecosystem. The biodiversity can show attractions in Yogyakarta city as a tourism destination in Indonesia. This research was conducted on three types of roads of the secondary artery (SA), secondary collector (SC), and local (L). The bird diversity depended on tree greenery as its habitat and food source. This research aimed (1) to analyze bird diversity on the roadside greenery in Yogyakarta City, and (1) to reveal the attraction of birds on the urban greenery as a tourism attraction. The sample units were selected by the method of stratified random sampling. The bird observation was used by the method of transect line conducted on the three categories of roads in Yogyakarta City. The bird diversity was analyzed by Shannon-Wiener's (H') index diversity, and bird activity was descriptively analyzed. The number of birds found in the greenery was 685 belong to 12 species. The diversity indexes (H') of the birds on the roads of the secondary artery (SA), secondary collector (SC), and local (L) categories were 0.697 (low), 1.001 (medium), and 1.246 (medium). The index shows the equal quality of the bird attractions in the city. The low-medium of index value should be improved to reach a high H'. The improvement should be carried out by landscape planning for urban tourism through planting food source trees or habitat trees for birds on the urban greenery of Yogyakarta. The strength of the urban attraction of birds was also supported by species diversity, conservation status, bird activity, habitat trees, and the ecological function of urban trees on the roadside greenery of Yogyakarta city.&#x0D; Keywords: bird diversity, roadside greenery, urban attraction, urban greenery, Yogyakarta

Effect of land use, habitat suitability, and hurricanes on the population connectivity of an endemic insular bat

Urbanization and natural disasters can disrupt landscape connectivity, effectively isolating populations and increasing the risk of local extirpation particularly in island systems. To understand how fragmentation affects corridors among forested areas, we used circuit theory to model the landscape connectivity of the endemic bat Stenoderma rufum within Puerto Rico. Our models combined species occurrences, land use, habitat suitability, and vegetation cover data that were used either as resistance (land use) or conductance layers (habitat suitability and vegetation cover). Urbanization affected connectivity overall from east to west and underscored protected and rustic areas for the maintenance of forest corridors. Suitable habitat provided a reliable measure of connectivity among potential movement corridors that connected more isolated areas. We found that intense hurricanes that disrupt forest integrity can affect connectivity of suitable habitat. Some of the largest protected areas in the east of Puerto Rico are at an increasing risk of becoming disconnected from more continuous forest patches. Given the increasing rate of urbanization, this pattern could also apply to other vertebrates. Our findings show the importance of maintaining forest integrity, emphasizing the considerable conservation value of rustic areas for the preservation of local biodiversity.

Spatial Patterns of Macrozoobenthos Assemblages in a Sentinel Coastal Lagoon: Biodiversity and Environmental Drivers

This study presents an assessment of the diversity and spatial distribution of benthic macrofauna communities along the Moulay Bousselham lagoon and discusses the environmental factors contributing to observed patterns. In the autumn of 2018, 68 stations were sampled with three replicates per station in subtidal and intertidal areas. Environmental conditions showed that the range of water temperature was from 25.0 °C to 12.3 °C, the salinity varied between 38.7 and 3.7, while the average of pH values fluctuated between 7.3 and 8.0. In vegetated habitats, biomass values of the seagrass Zostera noltei Hornemann ranged between 31.7 gDW/m² and 170.2 gDW/m² while the biomass of the seagrass Ruppia cirrhosa (Petagna) Grande between 54.2 gDW/m² and 84.7 gDW/m². Sediment analyses showed that the lagoon is mainly composed of sandy and silty sediments. We recorded 37,165 individuals of macrofauna distributed in 63 taxa belonging to 50 families, with a mean abundance value of 4582.8 ind/m² and biomass average of 22.2 g/m². Distance-based linear modeling analysis (DISTLM) identified sediment characteristics, water parameters and habitat type (biomass of Z. noltei) as the major environmental drivers influencing macrozoobenthos patterns. Our results clearly revealed that the hydrographic regime (marine and terrestrial freshwater), sediment distribution and characteristics and the type of habitat (vegetated vs. unvegetated substrate) are the key factors determining the species composition and patterns of macrozoobenthos assemblages.

Grassland vegetation and roads have dominant influence on decadal-scale spatial-temporal patterns of fires in a species-rich protected Terai habitat in northeastern India

The Terai ecoregion of the Himalayan foothills is among the most fire-affected ecosystems in the Indian sub-continent. Although most of the Terai has already been lost to agriculture and urbanization, the few remaining native habitats are strictly protected due to their high biodiversity and ecological importance. The use of fires to maintain vegetation and wildlife habitat in these protected areas is an integral part of forest management. Although fires are initiated by forest managers or local people, their eventual spread and behaviour are not controlled. We hypothesize that distributions of fires are determined by several direct and indirect drivers like fuel load, fuel moisture content, presence of natural or artificial fire breaks, and climatic attributes of precipitation and temperature. Using the moderate-resolution (375m) satellite sensor-based data we studied the environmental influence on the spatial-temporal patterns of fire events over 18 years (2000-2018) in a 519 km2 protected area in northeastern India. The park has a mosaic of vegetation formations – including dry and swampy alluvial grassland, early successional woodland, and moist tropical forest. Despite high rainfall, there is an intense dry season that renders the herbaceous vegetation susceptible to fires. Using spatial and spatial-temporal Poisson regression models in a rigorous conditional autoregressive Bayesian framework, we found that net primary productivity (a proxy of vegetation type and fuel load), distance to roads (a measure of human influence), elevation (through its influence on floods and vegetation type), and river area extent (by determining the area under vegetation) had a significant influence on the spatial distributions of fires. The climatic signal on interannual variation in fires was weak, but dry season rainfall reduced fire incidence. The disproportionate distribution of fires adjacent to roads compared to the interior, and the repeated burning of some grassland patches need to be addressed in fire management.

Global Trends in Air‐Water CO2 Exchange Over Seagrass Meadows Revealed by Atmospheric Eddy Covariance

AbstractCoastal vegetated habitats like seagrass meadows can mitigate anthropogenic carbon emissions by sequestering CO2 as “blue carbon” (BC). Already, some coastal ecosystems are actively managed to enhance BC storage, with associated BC stocks included in national greenhouse gas inventories. However, the extent to which BC burial fluxes are enhanced or counteracted by other carbon fluxes, especially air‐water CO2 flux (FCO2) remains poorly understood. In this study, we synthesized all available direct FCO2 measurements over seagrass meadows made using atmospheric Eddy Covariance, across a globally representative range of ecotypes. Of the four sites with seasonal data coverage, two were net CO2 sources, with average FCO2 equivalent to 44%–115% of the global average BC burial rate. At the remaining sites, net CO2 uptake was 101%–888% of average BC burial. A wavelet coherence analysis demonstrated that FCO2 was most strongly related to physical factors like temperature, wind, and tides. In particular, tidal forcing was a key driver of global‐scale patterns in FCO2, likely due to a combination of lateral carbon exchange, bottom‐driven turbulence, and pore‐water pumping. Lastly, sea‐surface drag coefficients were always greater than the prediction for the open ocean, supporting a universal enhancement of gas‐transfer in shallow coastal waters. Our study points to the need for a more comprehensive approach to BC assessments, considering not only organic carbon storage, but also air‐water CO2 exchange, and its complex biogeochemical and physical drivers.

Observations on the floristic, life-form, leaf-size spectra and habitat diversity of vegetation in the Bhimber hills of Kashmir Himalayas

Vegetation analysis provides the prerequisites to understand the overall community structure and function of any ecosystem and is a fundamental requirement for the precise evaluation of biodiversity. Although many studies have assessed floristic attributes of specific areas, there are still unexplored regions, as is the case of the mountain region in the Kashmir Himalayas. Current research highlighted the recent findings of the scientific characterization of floristic and ecological aspects on the forest flora found in the Bhimber hills, Pakistan. Floristically, a total of 93 species belonging to 80 genera in 41 families were recorded. The species distribution patterns across the families were disproportionate with half of the species contributed by 8 families and 25 families were monotypic. Based on the floristic analysis, Asteraceae was the largest family with 12% of species followed by Poaceae with (11%) species. PAST software, a multivariate ecological community analysis was used to classify the species similarities and differences among the different habitat types. According to the habitat wise distribution, 21% of species were growing in the natural forest habitat, while 15% of species were dispersed in highly distributed habitats along roadsides and 8% on pedestrians. In terms of functional diversity, the herbaceous growth form was dominant (58%). The biological spectrum revealed therophytes as the dominant life form as it indicates the disturbed habitat vegetation. The phytogeographical analysis revealed that the maximum (69%) species were native, while the minimum (31%) species were exotic. Thus, the study of these functional and habitat diversity patterns can significantly improve our understanding of the ecological aspects of the flora in the geographical location. This information may additionally be useful in devising management plans to ensure sustainable utilization and better management of forest landscapes in this Himalayan region.

Effects of Estuary-Wide Seagrass Loss on Fish Populations

Globally, habitat loss in coastal marine systems is a major driver of species decline, and estuaries are particularly susceptible to loss. Along the United States Pacific coast, monospecific eelgrass (Zostera marina) beds form the major estuarine vegetated habitat. In Morro Bay, California, eelgrass experienced an unprecedented decline of > 95%, from 139 ha in 2007 to < 6 ha by 2017. Fish populations were compared before and after the eelgrass decline using trawl surveys. Beach seines surveys were also conducted during the post-decline period to characterize species within and outside of remnant eelgrass beds. While the estuary-wide loss of eelgrass did not result in fewer fish or less biomass, it led to changes in species composition. The post-eelgrass decline period was characterized by increases in flatfish (mainly Citharichthys stigmaeus) and staghorn sculpin (Leptocottus armatus), and decreases in habitat specialists including bay pipefish (Syngnathus leptorhynchus) and shiner perch (Cymatogaster aggregata). There were similar trends inside and outside of remnant eelgrass patches. These findings support evidence across multiple ecosystems suggesting that the predominance of habitat-specialists predicts whether or not habitat loss leads to an overall decline in fish abundance. In addition, loss of critical habitats across seascapes can restrict population connectivity and lead to range contraction. For bay pipefish, the loss of eelgrass in Morro Bay is likely to create a population biogeographic divide. Currently, Morro Bay is dominated by flatfish and sculpins, and the longevity of this new ecosystem state will depend on future eelgrass recovery dynamics supported by ecosystem-based management approaches.

Another rejection of the more-individuals-hypothesis: Carrion beetles (Silphidae, Coleoptera) in the Southern Rocky Mountains

Beetles are the most diverse animal clade on the planet, and understanding the mechanisms underlying their diversity patterns is critical to understanding animal biodiversity in general. Using carrion beetles (Silphidae; Coleoptera), I test the more-individuals hypothesis (MIH), consisting of positive climatic impacts on food resources leading to increased abundance and then diversity. I also test competing mechanistic hypotheses, including interacting effects of climate, local vegetation, habitat diversity, habitat heterogeneity, soil diversity, and elevational area. Carrion beetle species richness and abundances were estimated using 40 standardized pitfall traps set for 90 days at 30 survey sites on two elevational gradients in the Front Range and San Juan Mountains, Colorado, USA. Standardized measurements assessed 13 vegetative characteristics, food resources (mammal abundances), soil diversity, habitat diversity, elevational area, temperature, precipitation and net primary productivity at each site. Structural equation models were used to test competing diversity hypotheses and mechanisms. Species richness peaked at intermediate elevations on both gradients, whereas abundance was unimodal on one gradient and decreasing on the other. The MIH mechanism was rejected; all four potential SEM model constructions were unsupported and the majority of all SEM models did not support relationships between abundance and diversity or climate and food resources. The best SEM model included direct influences of temperature, vegetation biomass, and food resources but with separate effects on diversity and abundance. Carrion beetles were more diverse and abundant in sites with dense understory vegetation and warm temperatures, while higher abundances were also linked to more food resources. This climate-biotic relationship is likely due to a need for microclimates and microhabitats to mediate physiological tradeoffs of desiccation and thermoregulation with predation. This suggests a general hypothesis for beetle diversity and abundance, particularly on arid-based mountains globally.

Ants species richness and diversity in relation to different ecological habitat in selected localities of the semi-arid region of Karnataka, India.

We analysed the taxonomic position and species diversity of ants in four different habitats (agriculture, vegetative, dry land, and human habitats). A total of 11,038 ant workers belonging to 40 species, 25 genera of 10 tribes, and six subfamilies were recorded. The Simpson index of diversity (1-D) was 0.97, indicating greater diversity in both vegetative and human habitat. Similarly, the Shannon index was 3.40 and 3.50 for both vegetative and human habitats, respectively, indicating assemblage of similar ant species in both habitats. In contrast, for agricultural habitat, Simpson index of diversity (1-D) was 0.90, and for dry land habitat, the least diversity of 0.80 was reported. However, in pair-wise comparisons, no significant difference was observed between agriculture and dry land and vegetative and human habitats. The agriculture and arid land habitats tend to have fewer species compared with the vegetative and human habitats. Human-disturbed areas have an important role as reservoirs of biodiversity and should be included in landscape management practices to improve ant conservation in the tropics.

Ultraviolet vision aids the detection of nutrient-dense non-signaling plant foods

To expand our understanding of what tasks are particularly helped by UV vision and may justify the costs of focusing high-energy light onto the retina, we used an avian-vision multispectral camera to image diverse vegetated habitats in search of UV contrasts that differ markedly from visible-light contrasts. One UV contrast that stood out as very different from visible-light contrasts was that of nutrient-dense non-signaling plant foods (such as young leaves and immature fruits) against their natural backgrounds. From our images, we calculated color contrasts between 62+ species of such foods and mature foliage for the two predominant color vision systems of birds, UVS and VS. We also computationally generated images of what a generalized tetrachromat, unfiltered by oil droplets, would see, by developing a new methodology that uses constrained linear least squares to solve for optimal weighted combinations of avian camera filters to mimic new spectral sensitivities. In all visual systems, we found that nutrient-dense non-signaling plant foods presented a lower, often negative figure-ground contrast in the UV channels, and a higher, often positive figure-ground contrast in the visible channels. Although a zero contrast may sound unhelpful, it can actually enhance color contrast when compared in a color opponent system to other channels with nonzero contrasts. Here, low or negative UV contrasts markedly enhanced color contrasts. We propose that plants may struggle to evolve better UV crypsis since UV reflectance from vegetation is largely specular and thus highly dependent on object orientation, shape, and texture.

Diversity of Ostrya carpinifolia Forests in Ravine Habitats of Serbia (S-E Europe)

We investigated vegetation in ravine habitats of Serbia, in order to classify hop hornbeam (Ostrya carpinifolia Scop.) forests in syntaxonomic terms, assess the effects of environmental factors on their floristic differentiation, and detect the biodiversity components of the analyzed communities. Both K-means clustering and Bayesian classification revealed five ecologically interpretable groups of forests that belong to the alliances Ostryo carpinifoliae-Fagion sylvaticae, Ostryo carpinifoliae-Tilion platyphylli, Fraxino orni-Ostryion carpinifoliae, Pseudofumario albae-Ostryion carpinifoliae, and Achilleo ageratifoliae-Ostryion carpinifoliae. Canonical correspondence analysis indicated that these alliances are clearly differentiated along a combined light–moisture gradient (from shade and mesic to sunny and xeric variants). The alpha diversity increases from xeric to mesic alliances. A lower alpha diversity in xeric forests may be explained by the stress conditions that prevent mesic species from colonizing the saxatile habitats. Extremely high—almost the greatest possible—values of both the species turnover and beta diversity were detected in all variants of the analyzed forests. Such high diversity may be the result of the strong environmental gradients in ravine habitats. The investigated forests represent an important pool of rare, paleo-endemic species that survived Quaternary glaciations in ravine refugia.

Characterizing Fish–Habitat Associations through Paired Fisheries‐Independent and In Situ Habitat Assessments

AbstractEstuarine habitat has a significant influence on the growth, recruitment, and survival of fish and invertebrate species, and understanding habitat dynamics can improve fisheries management. However, the cost and effort associated with habitat monitoring can be limiting, and many large‐scale fisheries‐independent monitoring programs do not capture habitat and biological data concurrently. Consequently, fisheries and their associated habitats are often managed separately. We designed a pilot study to assess the utility and effectiveness of incorporating rapid in situ habitat characterization into a statewide fisheries management program. The occurrence of six focal species (Red Drum Sciaenops ocellatus, Spotted Seatrout Cynoscion nebulosus, blue crab Callinectes sapidus, Atlantic Croaker Micropogonias undulatus, brown shrimp Farfantepenaeus aztecus, and white shrimp Litopenaeus setiferus) and the overall faunal community composition were compared across estuarine habitats to assess the ability of this method to accurately depict fish–habitat associations. Focal species’ occurrence and community composition was significantly correlated with shoreline vegetation, seagrass presence, presence of mangroves, substrate type, and heterogeneity in vegetated habitat. This study demonstrates an effective approach to integrating habitat into fisheries‐independent monitoring in pursuit of an ecosystem‐based approach to fisheries management.

Taxonomic and morphological diversity of the ground-dwelling ant fauna in Eastern Amazonian grasslands

Amazonian grassland ecosystems are poorly understood, highly threatened, and under-protected. This study combined taxonomic and trait-based diversity approaches to provide the first description of the diversity of the ground-dwelling ant fauna of grasslands in Eastern Amazonia. We surveyed two types of open vegetation habitats: campinarana (unique to Amazonia; five sites) and savanna (two sites). Of the 89 ground-dwelling ant species we collected from pitfall traps, a few species were characteristic of open vegetation habitats. We found significant differences among these sites in terms of their species richness, which was positively associated with vegetation complexity. Morphological diversity, via species richness, was positively related to flooding and negatively related to soil cover. In conclusion, we observed some characteristic ant species of open vegetation habitats in Amazonian grasslands, and morphologically rich, ground-dwelling ant fauna. Further, a trait-based approach improved our understanding of community organization in the Amazon, which is the most biodiverse tropical biome on Earth.