scholarly journals If you build it, they will come: rapid colonization by dragonflies in a new effluent-dependent river reach

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9856
Author(s):  
Michael T. Bogan ◽  
Drew Eppehimer ◽  
Hamdhani Hamdhani ◽  
Kelsey Hollien
Keyword(s):  
Species Richness ◽  
Urban Development ◽  
Natural Habitat ◽  
Treated Wastewater ◽  
Santa Cruz ◽  
Assemblage Composition ◽  
Santa Cruz River ◽  
Freshwater Habitats ◽  
River Reach ◽  
Study Sites

Background Aquatic ecosystems are greatly altered by urban development, including the complete loss of natural habitat due to water diversions or channel burial. However, novel freshwater habitats also are created in cities, such as effluent-dependent streams that rely on treated wastewater for flow. It is unclear how diverse these novel ecosystems are, or how quickly aquatic species are able to colonize them. In this study, we (1) quantify odonate (Insecta, Odonata) colonization of a novel effluent-dependent river reach, (2) examine how drying events affect odonates in these novel habitats, and (3) explore whether effluent-dependent streams can support diverse odonate assemblages. Methods We conducted monthly odonate surveys at three sites along the Santa Cruz River (Tucson, AZ, USA) between June 2019 and May 2020. One site was in a long-established effluent-dependent reach (flowing since the 1970s) that served as a reference site and two sites were in a newly-established reach that began flowing on June 24, 2019 (it was previously dry). We compared odonate species richness, assemblage composition, and colonization patterns across these reaches, and examined how these factors responded to flow cessation events in the new reach. Results Seven odonate species were observed at the study sites in the new reach within hours of flow initiation, and species rapidly continued to arrive thereafter. Within 3 months, species richness and assemblage composition of adult odonates were indistinguishable in the new and reference reaches. However, drying events resulted in short-term and chronic reductions in species richness at one of the sites. Across all three sites, we found over 50 odonate species, which represent nearly 40% of species known from the state of Arizona. Discussion Odonates were surprisingly diverse in the effluent-dependent Santa Cruz River and rapidly colonized a newly established reach. Richness levels remained high at study sites that did not experience drying events. These results suggest that consistent discharge of high-quality effluent into dry streambeds can be an important tool for promoting urban biodiversity. However, it remains to be seen how quickly and effectively less vagile taxa (e.g., mayflies, caddisflies) can colonize novel reaches. Effluent-dependent urban streams will always be highly managed systems, but collaboration between ecologists and urban planners could help to maximize aquatic biodiversity while still achieving goals of public safety and urban development.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Species Richness ◽  
Site Selection ◽  
Catchment Area ◽  
Sampling Design ◽  
Environmental Gradients ◽  
Large Sample Size ◽  
Sample Sizes ◽  
Assemblage Composition ◽  
Landscape Gradients ◽  
Freshwater Habitats

<i>Abstract.</i>—Linking landscape features, both natural and human-altered, to aquatic ecosystem structure and function is a fundamental objective in landscape ecology and freshwater science, but this process is data- and resource-intensive. Quantifying how landscape stressors influence aquatic communities requires balancing logistic and financial constraints with effectively sampling the landscape to capture gradients of interest. There are a variety of ways to balance these constraints, such as using existing data, handpicked site selection, or a statistical site-selection scheme. Poor sampling design reduces statistical power; however, we do not know how differences in site-selection designs influence our ability to measure ecological responses to landscape gradients. We quantified how the distribution of sample sites across landscape gradients affected the measured responses of stream fish assemblages to these gradients at different sample sizes. Specifically, we used randomization tests to compare the variability in the responses of fish assemblage structure (species richness and composition) to catchment area and land use (agricultural land) with manipulated distributions (random, highly skewed, and uniform) of sites across these landscape gradients. Assemblage composition was more sensitive than species richness to sampling design, and we observed less variability in the detected response of assemblage composition when samples were distributed uniformly across landscape gradients, especially when sample sizes were small. Although strong responses to environmental gradients, such as species richness to catchment area, are robust to sampling distributions, large sample size and a uniform distribution of samples might help elucidate more subtle responses to environmental gradients.

scholarly journals Family graveyards form underappreciated local plant diversity hotspots in China's agricultural landscapes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Natural Habitat ◽  
Plant Species Richness ◽  
Agricultural Landscapes ◽  
Natural Habitats ◽  
Landscape Features ◽  
Habitat Islands ◽  
Local Plant ◽  
Ecological Functioning

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.

scholarly journals Diversity, Concentration and Dynamics of Culturable Fungal Bioaerosols at Doha, Qatar

2020 ◽  
Vol 18 (1) ◽  
pp. 182
Author(s):  
Raghdaa K. Fayad ◽  
Roda F. Al-Thani ◽  
Fatima A. Al-Naemi ◽  
Mohammed H. Abu-Dieyeh
Keyword(s):  
Species Richness ◽  
Fungal Spores ◽  
Gravimetric Method ◽  
Fungal Spore ◽  
Industrial Area ◽  
Airborne Fungi ◽  
Culture Collection ◽  
Colony Count ◽  
Study Sites ◽  
Future Work

This research was conducted to investigate the dynamics of airborne fungi using viable culture collection and in respect to different abiotic variables, including seasonal and intra-diurnal variations. A gravimetric method was used to sample airborne fungal deposition on potato dextrose agar plates on alternate days, for a year between April 2015 to March 2016. From 176 settle plate exposures, a total of 1197 mould and 283 yeast colony-forming units (CFU), 21 genera and 62 species were retrieved. The highest fungal spore count was recorded in February 2016, whereas the lowest count occurred in August 2015. The main constituents of the fungal airspora were attributed to Cladosporium (60.2%), Aspergillus (10.4%), Fusarium (9.4%), Alternaria (8.5%), and Ganoderma spp. (2.3%). Temperature was negatively correlated with total colony count (r = −0.231, p ≤ 0.05) or species richness (r = −0.267, p ≤ 0.001), while wind speed was positively correlated with total colony count (r = 0.484, p ≤ 0.001) or species richness (r = 0.257, p ≤ −0.001). The highest dispersal of fungal spores was obtained at 18:00, whereas the lowest fungal spores release was recorded at 00:00 (midnight). There were no significant differences in species composition and richness of the airborne fungal population between two study sites, the Industrial area and Qatar University Campus. The count of Alternaria spp. and Fusarium spp. were significantly higher at the Industrial area site, which corresponds to a higher CO2 level than the Qatar University site. This study lays the foundation for future work to assess the implications of such aeromycological data on public health.

scholarly journals Climate change and water resources management in the Upper Santa Cruz River, Arizona

2015 ◽  
Vol 521 ◽  
pp. 18-33 ◽  
Author(s):  
Eylon Shamir ◽  
Sharon B. Megdal ◽  
Carlos Carrillo ◽  
Christopher L. Castro ◽  
Hsin-I Chang ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Resources Management ◽  
Santa Cruz ◽  
Resources Management ◽  
Santa Cruz River

scholarly journals Second floor, please: the fish fauna of floating litter banks in Amazonian streams and rivers

2013 ◽  
Vol 11 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Lucelia Nobre Carvalho ◽  
Luana Fidelis ◽  
Rafael Arruda ◽  
Andre Galuch ◽  
Jansen Zuanon
Keyword(s):  
Species Richness ◽  
Fish Assemblage ◽  
Amazon Basin ◽  
Stream Water ◽  
Fish Fauna ◽  
Assemblage Composition ◽  
Plant Matter ◽  
Carnivorous Species ◽  
Ephemeral Habitat ◽  
Dead Plant

Floating litter banks are an ephemeral habitat consisting of branches, twigs, flowers, seeds, and fruits that are trapped on the stream water surface by a variety of retention mechanisms. These heterogeneous materials form a deep layer of dead plant matter that is colonized by a variety of organisms, including fish that forage on the aquatic macroinvertebrates found in this unique habitat. In this study, we aimed to characterize which fish species occupy the floating litter banks and their trophic characteristics, as well as determine if fish assemblage composition and species richness can be predicted by the size of the floating litter banks. Fish sampling was conducted in five rivers located in the Amazon basin. Of the 31 floating litter banks sampled that contained fish, 455 individuals were recorded and were distributed within 40 species, 15 families and five orders. Siluriformes were the most representative order among the samples and contained the largest number of families and species. The fish fauna sampled was mainly composed of carnivorous species that are typically found in submerged litter banks of Amazonian streams. The fish assemblage composition in the kinon can be predicted by the volume of the floating litter banks using both presence/absence and abundance data, but not its species richness. In conclusion, kinon banks harbor a rich fish assemblage that utilizes this habitat for shelter and feeding, and may function as a refuge for the fishes during the peak of the flooding season.

scholarly journals Ichthyofauna sampled with tadpoles in northeastern Maranhão state, Brazil

Check List ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 1550 ◽  
Author(s):  
Rodrigo Matavelli ◽  
Aldenise Martins Campos ◽  
João do Vale ◽  
Nivaldo Magalhães Piorski ◽  
Paulo Dos Santos Pompeu
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
River Basins ◽  
Fish Diversity ◽  
Estuarine Ecosystems ◽  
Lotic Habitats ◽  
Freshwater Habitats ◽  
High Fish ◽  
Study Species

The Neotropic region has high fish diversity associated with freshwater habitats. However, for Maranhão state, most publications on the ichthyofauna concentrate on coastal or estuarine ecosystems. In this study, species of fish were sampled in lentic and lotic habitats in Cerrado areas (Cerradão phytophysiognomy) and in restinga areas (Atlantic Forest phytophysiognomy) in northeastern Maranhão state between January and July 2010. Thirteen species from 10 families and 6 orders were captured. Species richness was highest for the orders Characiformes and Gymnotiformes. Our results are the first records of the ichthyofauna of coastal drainage areas of northeastern Maranhão state, contributing to the understanding of the biodiversity of the Munim and Parnaíba River basins, and suggest the existence of a community that shares elements with those of the Amazon and Caatinga biomes.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Forested Wetlands ◽  
Timber Harvest ◽  
Large Wood ◽  
Catchment Scale ◽  
Southeast Alaska ◽  
Riparian Management ◽  
Freshwater Habitats ◽  
Study Sites ◽  
Landscape Attributes ◽  
Landscape Influences

<i>Abstract.</i>—Currently, much is known about influences of landscape attributes, including timber harvest practices, on large wood dynamics in streams. Comparatively, much less is known about influences of catchment attributes on Southeast Alaska streams, in part because of a historical lack of consistent catchment-scale data available for the region. As in forested regions elsewhere, large wood is an important resource to stream habitats and fishes in Southeast Alaska. Therefore, the purpose of this study was to characterize catchment-scale influences, including various timber harvest practices, on large wood in Southeast Alaska stream sites. We delineated local catchment boundaries for all stream reaches in the region and summarized landscape influences, including natural and harvest-related attributes in local and network catchments. Relative amounts of variation in four large wood habitat variables explained by natural versus harvest practice-related landscape attributes were evaluated to compare different influences on 28 randomly selected study sites. We used those results to predict variation in large wood variables from our sites through use of both natural and harvest practice-related catchment attributes to identify those that may be most influential to large wood. Natural characteristics, including catchment area, deciduous forests, forested wetlands, and catchment slope, all had significant influences on large wood variables, as did various measures of contemporary and historical timber harvest practices. We found that large wood length was positively related to conventional harvest after 1990, suggesting the potential effectiveness of contemporary logging regulations in protecting large wood characteristics. In our study, both natural and timber harvest practice-related attributes had measureable influences on stream habitat, underscoring the importance of considering catchment-scale attributes, including riparian management schemes, for managing Southeast Alaska streams.

scholarly journals Environmental filtering and spillover explain multi-species edge responses across agricultural boundaries in a biosphere reserve

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
J. van Schalkwyk ◽  
J. S. Pryke ◽  
M. J. Samways ◽  
R. Gaigher
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Habitat Quality ◽  
Environmental Variables ◽  
Natural Habitat ◽  
Environmental Filtering ◽  
Biosphere Reserve ◽  
Natural Habitats ◽  
Habitat Specificity ◽  
Induced Changes

Abstract To ensure integrity of protected areas we need to understand how species respond to anthropogenic borders. We investigate, from a metacommunity perspective, the direct and indirect mechanisms by which transformed areas affect distribution patterns of ground-living arthropod assemblages inhabiting an extensive protected area adjacent to fruit orchards in an important biosphere reserve. Arthropods and environmental variables were sampled along transects perpendicular to natural-orchard edges. Influence of distance from orchard boundary, degree of impermeability of the boundary, orchard habitat quality (local scale land-use intensity), and edge-induced changes in local environmental variables on arthropod species richness and composition in non-crop habitats were assessed. Arthropod groups were assessed in terms of habitat fidelity: species associated with natural habitat (stenotopic species), those within crop habitat (cultural species), and those showing no preference for either habitat (ubiquitous species). Spillover resulted in higher cultural species richness near edges, but not higher overall species richness. Environmental filtering was important for stenotopic species composition, which was influenced by edge-induced changes in environmental variables. Ubiquitous species composition was determined by orchard impermeability. Increased orchard habitat quality was associated with higher cultural and ubiquitous species richness. The effects of orchards on assemblages in natural habitats can be variable, but predictable when using species habitat specificity in conjunction with a metacommunity framework. High intensity orchards may act as sink habitats, especially for species that readily disperse between crop and natural habitats. Here we recommend that local buffer strips are > 85 m wide, which will reduce the influence of cultural species spillover on sensitive natural ecosystems.

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