Urbanization Effect on the Ant Diversity and Composition in an Arid City

2021 ◽  
Author(s):  
Mahmoud Saleh Abdel-Dayem ◽  
Gamal Mohamed Orabi ◽  
Mostafa Rizk Sharaf ◽  
Jonathan David Majer ◽  
Mohammed Khalid Al-Sadoon ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Indicator Species ◽  
Native Species ◽  
Ground Cover ◽  
Diversity Indices ◽  
Urbanization Effect ◽  
Urbanization Gradient ◽  
Ant Assemblages ◽  
Soil Variables ◽  
Urbanization Gradients

The dramatic increased rates of uncontrolled urbanization in various parts of the World have resulted in loss of native species and overall threats to biodiversity. Over the last few decades Saudi Arabia has witnessed a remarkably rapid population growth and unparalleled levels of urbanization, leading to threats to biodiversity. Ants were pitfall-trapped across an urban-rural gradient to evaluate ant assemblage responses to urbanization in Wadi Hanifa, Riyadh, Central Saudi Arabia. Fifteen sampling sites were selected along three different urbanization gradients, each traversing urban, suburban and rural zones. Within each site 10 traps were distributed and operated for 7 consecutive days, at 3-monthly intervals throughout one year. Vegetation, ground cover, and chemical and physical soil variables at sampling sites were analyzed concurrently. Ant abundance, species richness, evenness, and diversity indices of Shannon and Simpson were calculated for each site using PC-ORD to demonstrate diversity patterns along the urbanization gradients. Ant assemblages were assessed by detrended corresponding analysis (DCA), canonical correspondence analysis (CCA), and analysis of similarity (ANOSIM) using PC-ORD. Indicator species analysis was conducted to define representative species along the urbanization gradient. A total of 42 ant species were identified. The diversity parameters were consistent across the urbanization gradient. However, significant differences were observed in the ant assemblages between rural and urban, suburban and urban, but only marginal between rural and suburban. Eleven ant species were identified as indicator species (IV values between 50.7-80.7%). The ant assemblages were influenced by flora, ground cover, and soil variables.

scholarly journals Idiosyncrasies in cities: evaluating patterns and drivers of ant biodiversity along urbanization gradients

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Abe Perez ◽  
Sarah E Diamond
Keyword(s):  
United States ◽  
Species Diversity ◽  
Native Species ◽  
Biodiversity Loss ◽  
Urban Biodiversity ◽  
Partial Support ◽  
Urbanization Gradient ◽  
Native Communities ◽  
Urbanization Gradients ◽  
Over Time

Abstract Urbanization is expected to reduce biodiversity. However, an increasing number of studies report urban biodiversity comparable to that of surrounding nonurban areas, leaving open the question: what maintains biodiversity in cities? We characterized patterns of ant biodiversity across urbanization gradients of three major cities in the Midwestern United States and evaluated the support for two mechanisms underlying the maintenance of biodiversity in cities, specifically via introduced non-native species and differential phenology of communities along each urbanization gradient. We observed idiosyncrasies in ant species diversity such that each city displayed either increased, decreased or no change in biodiversity across the urbanization gradient. We found partial support (one of the three cities) for the hypothesis that non-native species can contribute positively to overall species diversity in cities, though even with introduced species removed from consideration, native ant biodiversity was maintained along the urbanization gradient. We found no support for systematic differential phenology across urbanization gradients, although species diversity did vary over time across all sites. Our results further challenge the assumption of biodiversity loss in cities, as two of our three cities exhibited maintained species diversity along the urbanization gradient. Most importantly, our study demonstrates that urban biodiversity can be maintained entirely by native communities.

scholarly journals Biodiversity outcomes of an urban revegetation programme in Wellington, New Zealand: The role of patch size, isolation, age and the urban matrix

2021 ◽  
Author(s):  
◽  
Nicky OliverSmith
Keyword(s):  
Key Management ◽  
Native Species ◽  
Patch Size ◽  
Essential Element ◽  
Ground Cover ◽  
Structural Diversity ◽  
Pitfall Traps ◽  
Reference Sites ◽  
The Matrix ◽  
Vegetation Surveys

<p>Urban revegetation programmes are an important contribution to the biodiversity of our landscape environment. Wellington city has, for nearly two decades, promoted revegetation of the city with a focus in latter years on eco-sourced native species. This is a substantial urban greening project planting 100,000 native plants per annum. This thesis analyses the native revegetation programme and posits recommendations for continuance and enhancement for consideration.  Data were collected from a sample set of twenty revegetated sites and four reference sites in Wellington city. Two transects per site were set up with invertebrate pitfall traps, lizard pitfall traps, lizard tree covers, bird count stations and vegetation surveys. The data were collected over a twelve-month period. Ordination was used to examine the community composition of revegetation sites in relation to each other and the four reference sites. Multiple regression was used to examine the influence of patch age, patch size, isolation and residential land cover upon a range of biodiversity variables.   The key findings of this study are that revegetated sites lacked the level of ground cover by native seedlings that were characteristic of the mature reference sites. Also found was that revegetation sites in Wellington City require around ten years of growth before natural regeneration of native seedlings began to become apparent.  Large native birds were more likely to be found in close proximity to mature primary bush, confirming that mature primary bush is an essential element of the landscape. Weta were found in increased numbers as distance from mature primary bush increased. Northern grass skinks were the only species of lizard found, in association with a higher proportion of residential area in the matrix.   The key management recommendations of this study are; the development of a collaborative connective strategy; further enrichment planting designed to maximize structural diversity over time; the investment in well planned robust monitoring programmes.  This research contributes to the understanding of biodiversity outcomes of an urban native revegtation programme, providing baseline data for future monitoring purposes.</p>

Earthworm diversity in Rio Grande do Sul, Brazil

Zootaxa ◽  
2018 ◽  
Vol 4496 (1) ◽  
pp. 562 ◽  
Author(s):  
GERUSA PAULI KIST STEFFEN ◽  
RICARDO BEMFICA STEFFEN ◽  
MARIE LUISE CAROLINA BARTZ ◽  
SAMUEL WOOSTER JAMES ◽  
RODRIGO JOSEMAR SEMINOTTI JACQUES ◽  
...  
Keyword(s):  
Species Richness ◽  
Native Species ◽  
Rio Grande ◽  
First Record ◽  
Diversity Indices ◽  
Morphological Characters ◽  
Rio Grande Do Sul ◽  
Earthworm Species ◽  
Aporrectodea Trapezoides ◽  
Native Pastures

The knowledge regarding earthworm species richness in subtropical Brazil is limited, particularly in the state of Rio Grande do Sul (RS), where only a few sites have been sampled. In this study we assessed earthworm richness in different ecosystems of RS, prioritizing un-sampled regions. Fifteen ecosystems, including native vegetation and other ecosystems with variable levels of disturbance were sampled in 30 counties in RS, totaling 77 sampling points, mainly in the Pampa biome. Qualitative sampling was performed by handsorting soil monoliths and fixing the earthworms in 4% formalin solution. Species identification was based on morphological characters, and species richness and Shannon (H) and McIntosh (U) diversity indices were calculated for each ecosystem. Twenty-one earthworm species were identified, belonging to seven families: Glossoscolecidae (8), Rhinodrilidae (2), Ocnerodrilidae (4), Megascolecidae (4), Acanthodrilidae (1), Lumbricidae (1) and Criodrilidae (1). From these, ten are new species belonging to the genera: Glossoscolex (6), Fimoscolex (1), Kerriona (1), Eukerria (1), and one aquatic species of the Criodrilidae family, belonging to a new genus. Most of the native species (Urobenus brasiliensis, Fimoscolex n.sp.1 and the Glossoscolex spp.) predominated in ecosystems little altered by human activity, while exotic (Amynthas gracilis, Amynthas rodericensis, Metaphire californica, Aporrectodea trapezoides) and peregrine species (Pontoscolex corethrurus) predominated in areas with more human disturbance. Native ecosystems with lower disturbance, particularly forests and native pastures had higher diversity than disturbed sites. This is the first record of A. rodericencis for Brazil and most sites represent new collection records for the known species in RS.

scholarly journals Effects of abiotic variables on the distribution of fish assemblages in streams with different anthropogenic activities in southern Brazil

2012 ◽  
Vol 10 (3) ◽  
pp. 643-652 ◽  
Author(s):  
Vanessa Salete Daga ◽  
Éder André Gubiani ◽  
Almir Manoel Cunico ◽  
Gilmar Baumgartner
Keyword(s):  
Native Species ◽  
Fish Assemblages ◽  
Anthropogenic Activities ◽  
Southern Brazil ◽  
Urbanization Gradient ◽  
Composition And Structure ◽  
Matrix Correlation ◽  
Abiotic Variables ◽  
The Relationship ◽  
Distribution Of Fish

Studies on fish assemblages in streams point out, that understanding the relationship between species and their environment is crucial for conservation. The present study aimed at evaluating the effects of changes in abiotic variables on the composition and structure of fish assemblages in Neotropical urban streams from southern Brazil with different levels of urbanization. The composition and structure of fish assemblages showed significant differences along the urbanization gradient observed in the streams. Tolerant and non-native species were found in more urbanized sites. A matrix correlation revealed a relationship between abiotic variables and the spatial pattern of structure and composition of fish assemblages. Abiotic variables, such as total phosphorus, dissolved oxygen, and conductivity, determined the distribution of fish assemblages. Streams without urban influence exhibited intrinsically low species richness, suggesting that they are highly susceptible to species loss and diversity reduction. Thus, changes in water quality or hydrological conditions induced by urbanization may intensify these impacts.

scholarly journals The Analysis of the Forest Flora of the Strzyżowskie Foothills from the Perspective of Presence of Anthropogenic Species

2011 ◽  
Vol 7 ◽  
pp. 99-110 ◽  
Author(s):  
Krystyna Towpasz ◽  
Alina Stachurska-Swakoń
Keyword(s):  
Alien Species ◽  
Indicator Species ◽  
Native Species ◽  
Beech Forest ◽  
Western Carpathians ◽  
Anthropogenic Pressure ◽  
Ancient Woodland ◽  
Forest Flora ◽  
Ancient Woodland Indicator Species ◽  
Calamagrostis Epigejos

The anthropogenic pressure of the forest communities of the Strzyżowskie Foothills (the Western Carpathians) was estimated on the basis of phytosociological materials. Carr communities are among the most threatened by invasive and alien species of the forest flora. The phenomenon of invasiveness of native species such as Calamagrostis epigejos or Carex brizoides was described. The highest number of ancient woodland indicator species was noted in the beech forest.

scholarly journals Biodiversity outcomes of an urban revegetation programme in Wellington, New Zealand: The role of patch size, isolation, age and the urban matrix

2021 ◽  
Author(s):  
◽  
Nicky OliverSmith
Keyword(s):  
Key Management ◽  
Native Species ◽  
Patch Size ◽  
Essential Element ◽  
Ground Cover ◽  
Structural Diversity ◽  
Pitfall Traps ◽  
Reference Sites ◽  
The Matrix ◽  
Vegetation Surveys

<p>Urban revegetation programmes are an important contribution to the biodiversity of our landscape environment. Wellington city has, for nearly two decades, promoted revegetation of the city with a focus in latter years on eco-sourced native species. This is a substantial urban greening project planting 100,000 native plants per annum. This thesis analyses the native revegetation programme and posits recommendations for continuance and enhancement for consideration.  Data were collected from a sample set of twenty revegetated sites and four reference sites in Wellington city. Two transects per site were set up with invertebrate pitfall traps, lizard pitfall traps, lizard tree covers, bird count stations and vegetation surveys. The data were collected over a twelve-month period. Ordination was used to examine the community composition of revegetation sites in relation to each other and the four reference sites. Multiple regression was used to examine the influence of patch age, patch size, isolation and residential land cover upon a range of biodiversity variables.   The key findings of this study are that revegetated sites lacked the level of ground cover by native seedlings that were characteristic of the mature reference sites. Also found was that revegetation sites in Wellington City require around ten years of growth before natural regeneration of native seedlings began to become apparent.  Large native birds were more likely to be found in close proximity to mature primary bush, confirming that mature primary bush is an essential element of the landscape. Weta were found in increased numbers as distance from mature primary bush increased. Northern grass skinks were the only species of lizard found, in association with a higher proportion of residential area in the matrix.   The key management recommendations of this study are; the development of a collaborative connective strategy; further enrichment planting designed to maximize structural diversity over time; the investment in well planned robust monitoring programmes.  This research contributes to the understanding of biodiversity outcomes of an urban native revegtation programme, providing baseline data for future monitoring purposes.</p>

scholarly journals Constructing ecological indices for urban environments using species distribution models

2021 ◽  
Author(s):  
Ariel Levi Simons ◽  
Stevie Caldwell ◽  
Michelle Fu ◽  
Jose Gallegos ◽  
Michael Gatheru ◽  
...  
Keyword(s):  
Los Angeles ◽  
Species Distribution ◽  
Indicator Species ◽  
Environmental Conditions ◽  
Native Species ◽  
Species Distribution Models ◽  
Urban Environments ◽  
Ecological Indices ◽  
Distribution Models ◽  
The Mean

Abstract In an increasingly urbanized world, there is the need for a framework to assess ecological conditions in these anthropogenically dominated environments. Using species observations from the Global Biodiversity Information Facility (GBIF), along with remotely sensed environmental layers, we used MaxEnt to construct species distribution models (SDMs) of native and non-native species in Los Angeles. 25 native and non-native Indicator species were selected based on the sensitivities of their SDM, as measured by the Symmetric Extremal Dependence Index (SEDI), to environmental gradients. These SDMs were summarized to produce ecological indices of native and non-native biodiversity in Los Angeles. We found native indicator species to have a greater sensitivity to environmental conditions than their non-native counterparts, with the mean SEDI score of native and non-native species MaxEnt models being 0.72 and 0.71 respectively. While both sets of species were sensitive to land use categories and housing density, native species were more sensitive to natural landscape variables while non-native ones were more sensitive to measures of water and soil contamination. Using random forest modeling we also found our native index could be more reliably predicted, given environmental conditions, than its non-native counterpart. The mean Pearson correlation between actual and predicted index values were 0.86 and 0.84 for native and non-native species. From these results we conclude that using SDMs to predict the biodiversity of environmental species is a suitable approach towards evaluating ecological conditions in urban environments, with the environmental sensitivity of native SDMs outperforming non-native ones.

Recreational Changes in the Forest Ecosystem Components: Case Study of the Cultural Heritage Site “White Sea Petroglyphs” (Republic of Karelia)

2020 ◽  
pp. 90-105
Author(s):  
A.V. Tuyunen ◽  
◽  
V.V. Timofeeva ◽  
A.Yu. Karpechko ◽  
Y.N. Tkachenko ◽  
...  
Keyword(s):  
Native Species ◽  
White Sea ◽  
Plant Cover ◽  
Ground Cover ◽  
Tree Seedlings ◽  
Percent Cover ◽  
Tree Stand ◽  
Rock Outcrops ◽  
Heritage Site ◽  
Recreation Impact

Recreation digression of forest ecosystems in the heritage site “White Sea Petroglyphs” was studied for the first time. This site is a compact system of rock outcrops partially cleared of forest vegetation, which bear Neolithic rock carvings (petroglyphs), and are linked together by walking trails. Patterns have been identified in the transformation of soils, plant cover components (tree stand, tree seedlings, understory and living ground cover), as well as fine roots (within 3 mm in diameter) of woody species under the recreation impact. Trampling was found to deform and destroy the top soil horizons, entailing a significant loss of the forest floor thickness and organic matter stores. Overall, the flora of the area is quite well preserved; 95–100 % of which is represented by native species. The living ground cover is noticeably damaged in the most actively used sites (fragments of trails and vista points). They feature a poor species composition, shrinking of the herb-dwarf shrub and moss-lichen cover, and a low percent cover of grassland and ruderal species. Easily accessible and actively visited sites have no or reducing amounts of tree seedlings, the tree stand is damaged and forest regeneration is hampered – the number of viable seedlings is minimal (100 pcs/ha). The mass of roots below 3 mm in diameter in heavily trampled trails showed a reduction of up to 74 %, while the root saturation in less affected trails slightly increased. Recreation transformations of the plant communities have not resulted in a loss of their resilience so far. The recreational digression in the studied sites was classified into stages I–III (weakly disturbed – strongly disturbed). Function zoning of the area should be modified using recreation-tolerant communities more intensively in order to reduce recreation impact. The most damaged areas, which are losing their stability, should be excluded from active use by modification of walking trails and building additional boardwalks.

Comparison of fungal endophyte communities in the invasive panicoid grass Hyparrhenia hirta and the native grass Bothriochloa macra

2007 ◽  
Vol 55 (2) ◽  
pp. 178 ◽  
Author(s):  
Ian R. White ◽  
David Backhouse
Keyword(s):  
Community Structure ◽  
Native Species ◽  
Fungal Endophytes ◽  
Diversity Indices ◽  
Fungal Endophyte ◽  
Plant Interactions ◽  
Similar Frequency ◽  
Degree Of Dominance ◽  
Significant Difference ◽  
Stems And Leaves

Communities of fungal endophytes from roots, stems and leaves of the introduced grass Hyparrhenia hirta (Coolatai grass) and the native species Bothriochloa macra (redgrass) were compared at two sites to identify characteristics that may be associated with invasiveness of H. hirta. The most frequently isolated fungi from both hosts were species of Nigrospora, Alternaria, Cladosporium, Phoma, Epicoccum, Fusarium and Periconia. Most of these occurred at a similar frequency in the two hosts, although Nigrospora sphaerica was much more frequently isolated from H. hirta at both sites. There was little support for the hypothesis that the introduced species (H. hirta) would have a less diverse endophyte community than the native species. There was a greater degree of dominance by the most frequent species in communities from H. hirta than from B. macra, leading to lower diversity indices, but no significant difference in species richness. Cluster analysis of the endophyte communities suggested that host had a greater influence than site on community structure, and that this was expressed mostly in the relative frequency of fungi isolated from stems and leaves, with very similar fungal communities present in the roots of both species at both sites. Analysis of co-occurrence showed no evidence that competition among fungi affected community structure within individual plants. The dominance of N. sphaerica in H. hirta was therefore due to fungus–plant interactions rather than fungus–fungus interactions. Interactions with N. sphaerica could potentially affect the population ecology of H. hirta.

scholarly journals Restoration of eucalypt grassy woodland: effects of experimental interventions on ground-layer vegetation

2014 ◽  
Vol 62 (7) ◽  
pp. 570 ◽  
Author(s):  
S. McIntyre ◽  
R. B. Cunningham ◽  
C. F. Donnelly ◽  
A. D. Manning
Keyword(s):  
Coarse Woody Debris ◽  
Native Species ◽  
Woody Debris ◽  
Ground Cover ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Ground Layer ◽  
Total Biomass ◽  
Eastern Australia ◽  
Main Driver

We report on the effects of broad-scale restoration treatments on the ground layer of eucalypt grassy woodland in south-eastern Australia. The experiment was conducted in two conservation reserves from which livestock grazing had previously been removed. Changes in biomass, species diversity, ground-cover attributes and life-form were analysed over a 4-year period in relation to the following experimental interventions: (1) reduced kangaroo density, (2) addition of coarse woody debris and (3) fire (a single burn). Reducing kangaroo density doubled total biomass in one reserve, but no effects on exotic biomass, species counts or ground cover attributes were observed. Coarse woody debris also promoted biomass, particularly exotic annual forbs, as well as plant diversity in one of the reserves. The single burn reduced biomass, but changed little else. Overall, we found the main driver of change to be the favourable growth seasons that had followed a period of drought. This resulted in biomass increasing by 67%, (mostly owing to the growth of perennial native grasses), whereas overall native species counts increased by 18%, and exotic species declined by 20% over the 4-year observation period. Strategic management of grazing pressure, use of fire where biomass has accumulated and placement of coarse woody debris in areas of persistent erosion will contribute to improvements in soil and vegetation condition, and gains in biodiversity, in the future.

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