scholarly journals ROAD DENSITY AND POTENTIAL IMPACTS ON WILDLIFE SPECIES SUCH AS AMERICAN MOOSE IN MAINLAND NOVA SCOTIA

2004 ◽  
Vol 42 (2) ◽  
Author(s):  
Karen F. Beazley ◽  
Tamaini V. Snaith ◽  
Frances MacKinnon ◽  
David Colville
Keyword(s):  
Nova Scotia ◽  
Habitat Suitability ◽  
Biological Effects ◽  
Natural Populations ◽  
Road Construction ◽  
Significant Negative Correlation ◽  
Anthropogenic Factors ◽  
Natural Areas ◽  
Road Density ◽  
Buffer Zones

Habitat conversion, degradation and fragmentation, and the introduction of exotic species are among the primary factors causing the loss of biodiversity. Road density is a valuable indicator of these anthropogenic factors. Deleterious biological effects extend more than 1000 metres from roads, and road density of 0.6 km/km2 has been identified as an apparent threshold value above which natural populations of certain large vertebrates decline. Road density assessments in Nova Scotia indicate that many areas exceed this threshold. Multivariate logistic regression analyses indicate relationships between road density, moose pellet distribution, and habitat suitability values. Road density has a statistically significant negative correlation with moose pellets, such that as road density increases, the probability of moose pellet presence decreases. Road density alone and road density in combination with habitat suitability index values predict the presence of moose pellets, whereas habitat suitability values alone do not. Thus, road density may be an indicator of moose habitat selection or effectiveness in mainland Nova Scotia. Biodiversity conservation activities in Nova Scotia and elsewhere could focus on discouraging further road densities above 0.6 km/km2; protecting remaining roadless and low road density areas; minimizing new road construction, especially in natural areas; decommissioning and regenerating old logging roads; increasing buffer zones between natural areas and roads; and providing road crossings for wildlife in the form of under and overpasses.La conversion, la dégradation et la fragmentation des habitats ainsi que l’introduction d’espèces exotiques figurent parmi les principaux facteurs responsables de la réduction de la biodiversité. La densité routière est un indicateur précieux de ces facteurs anthropiques. Des effets biologiques négatifs se font sentir à plus de 1 000 mètres des routes, et il semble qu’une densité routière de 0,6 km/km2 constitue un seuil au-dessus duquel les populations naturelles de certains gros vertébrés diminuent. En Nouvelle-Écosse, la densité routière dépasse ce seuil dans plusieurs régions. Des analyses de régression logistique multivariée révèlent des relations entre la densité routière, la répartition des excréments d’orignaux et les valeurs de qualité de l’habitat. Il existe une corrélation négative significative entre la densité routière et les excréments d’orignaux, l’augmentation de la densité routière réduisant la probabilité de la présence d’excréments. La densité routière seule et la densité routière combinée aux valeurs de l’indice de qualité de l’habitat permettent de prévoir la présence d’excréments d’orignaux, tandis que les valeurs de qualité de l’habitat seules ne peuvent le faire. Par conséquent, la densité routière peut être un indicateur du choix ou de l’utilité de l’habitat pour l’orignal dans la partie continentale de la Nouvelle-Écosse. Dans cette province et ailleurs, les activités de conservation de la biodiversité pourraient mettre l’accent sur le maintien de la densité routière à moins de 0,6 km/km2, sur la protection des zones sans route et à faible densité routière, sur la réduction de la construction de nouvelles routes, en particulier dans les régions naturelles, sur la mise hors-service et la restauration des vieux chemins d’exploitation forestière, sur l’augmentation des zones tampons entre les régions naturelles et les routes et sur l’aménagement de traversées routières (tunnels et viaducs) pour les animaux sauvages.

Quantifying loss and degradation of former American marten habitat due to the impacts of forestry operations and associated road networks in northern Idaho, USA

2018 ◽  
Author(s):  
Samuel A. Cushman ◽  
Tzeidle N. Wasserman
Keyword(s):  
Habitat Loss ◽  
Habitat Suitability ◽  
Forest Type ◽  
Road Construction ◽  
Timber Harvest ◽  
Road Density ◽  
American Marten ◽  
Detection Rates ◽  
Northern Idaho ◽  
The Impact

American marten are associated with extensive and unfragmented late seral forest habitats, and are often considered to be particularly vulnerable to habitat loss and fragmentation. This chapter evaluates the impact of road building and timber harvest on habitat suitability for marten in northern Idaho, USA, using an empirically derived, multi-scale habitat suitability model, reconstructing key predictor variables (elevation, forest type, road density, canopy cover, landscape fragmentation and the extensiveness of late seral forest in the landscape) as they appear to have existed prior to harvest, and applying the model to both current and pre-harvest conditions. Calculating changes in the extent and pattern of habitat in the landscape indicate that timber harvest and road construction together reduced marten habitat quality considerably across the study area, which is likely responsible for current patterns of reduced detection rates and lower genetic diversity in areas that have experienced the largest amounts of habitat loss.

Urbanization of fauna on the example of marsh frog (Pelophylax ridibundus)

2015 ◽  
Vol 26 (3-4) ◽  
pp. 116-123
Author(s):  
A. P. Korzh ◽  
T. V. Zahovalko
Keyword(s):  
Urban Areas ◽  
Cognitive Modeling ◽  
Negative Impact ◽  
Natural Populations ◽  
Cellular Level ◽  
Anthropogenic Factors ◽  
Migration Routes ◽  
Corrective Effect ◽  
The Impact ◽  
The City

Recently, the number of published works devoted to the processes of synanthropization of fauna, is growing like an avalanche, which indicates the extreme urgency of this theme. In our view, the process of forming devices to coexist with human and the results of his life reflects the general tandency of the modern nature evolution. Urbanization is characteristic for such a specific group of animals like amphibians, the evidence of which are numerous literature data. Many researchers use this group to assess the bioindicative quality of the environment. For this aim a variety of indicators are used: from the cellular level of life of organization up to the species composition of the group in different territories. At the same time, the interpretation of the results is not always comparable for different areas and often have significantly different interpretations by experts. Urban environment, primarily due to the contamination is extremely aggressive to amphibians. As a consequence, the urban populations of amphibians may be a change in the demographic structure, affecting the reproductive ability of the population, the disappearance of the most sensitive species or individuals, resizing animals, the appearance of abnormalities in the development, etc. At the same time play an important amphibians in the ecosystems of cities, and some species in these conditions even feel relatively comfortable. Therefore, it is interesting to understand the mechanisms of self-sustaining populations of amphibians in urban environments. To assess the impact of natural and anthropogenic factors on the development of amphibian populations were used cognitive modeling using the program Vensim PLE. Cognitive map of the model for urban and suburban habitat conditions were the same. The differences concerned the strength of connections between individual factors (migration, fertility, pollution) and their orientation. In general, factors like pollution, parasites, predators had negative impact on the population, reducing its number. The birth rate, food and migration contributed to raising number of individuals. Some of the factors affected on the strength to of each other as well: the majority of the factors affected the structure of the population, had an influence on the fertility. Thanks to it the model reflects the additive effect of complex of factors on the subsequent status of the population. Proposed and analyzed four scenarios differing strength and duration of exposure. In the first scenario, a one-time contamination occurs and not subsequently repeated. The second and third scenario assumes half board contamination, 1 year (2 scenario) and two years (scenario 3). In the fourth scenario, the pollution affected the population of amphibians constantly. In accordance with the results of simulation, much weaker than the natural populations respond to pollution - have them as an intensive population growth and its disappearance at constant pollution is slow. Changes to other parameters of the model showed that this pollution is the decisive factor -only the constant action leads to a lethal outcome for the populations. All other components of the model have a corrective effect on the population dynamics, without changing its underlying trand. In urban areas due to the heavy impact of pollution maintaining the population is only possible thanks to the migration process – the constant replenishment of diminishing micropopulations of natural reserves. This confirms the assumption that the form of existence metapopulations lake frog in the city. In order to maintain the number of amphibians in urban areas at a high level it is necessary to maintain existing migration routes and the creation of new ones. Insular nature of the placement of suitable habitats in urban areas causes the metapopulation structure of the types of urbanists. Therefore, the process of urbanization is much easier for those species whicht are capable of migration in conditions of city. In the initial stages of settling the city micropopulationis formed by selective mortality of the most susceptible individuals to adverse effects. In future, maintaining the categories of individuals is provided mainly due to migration processes metapopulisation form of the species of existence is supported). It should be noted that the changes in the previous levels are always saved in future. In the case of reorganizations of individuals we of morphology can assume the existence of extremely adverse environmental conditions that threaten the extinction of the micropopulations. 

Sedimentological and Biological Changes Associated with the Construction of the Oil Terminal of Antifer, France

1984 ◽  
Vol 16 (3-4) ◽  
pp. 399-406
Author(s):  
Y Monbet
Keyword(s):  
Grain Size ◽  
Environmental Changes ◽  
Biological Effects ◽  
Standing Stock ◽  
Natural Populations ◽  
Benthic Fauna ◽  
Field Investigations ◽  
Mean Grain Size ◽  
To Receive ◽  
Principal Species

A study was conducted to gain insight on actual sedimentological and biological effects associated with the construction of an oil Terminal designed to receive 500 000 d.w.t. tankers. Field investigations and subsequent laboratory analyses were organized to evaluate the nature and magnitude of environmental changes on benthic macrofauna, three years after the end of the construction. Sediments were found to decrease dramatically in medium grain size in area sheltered by the newly built breakwater. Increase of percentage of silt and clays (90 % against 20 %) was observed leeward of the jetty. The benthic fauna showed significant modifications. Although the same community (Pectinaria kareni Abra alba) recolonized the bottom after the dredging of up to 30 × 106 m3 of sediments, increase in abundance occured. Biomass remained at a constant level and decrease of diversity was observed. Considering the rate of siltation, and assuming a constant siltation rate equal to the rate observed from 1975 to 1978, a simple regressive model relating biomass to mean grain size of sediments has been developped. This model allowed the prediction of biomass and production of the two principal species for the period 1978 – 1981. Continuous siltation within the harbor leads to a maximum of biomass from years after the end of the construction, followed by a decrease of standing stock. This process may be explained by the respective tolerance of the two principal species to increase silt contant and also probably by the accumulation of organic matter which may impede the development of natural populations.

scholarly journals Status of Astragalus cornutus Pall. populations in the Samara Region

2018 ◽  
Vol 7 (1) ◽  
pp. 37-41
Author(s):  
Valentina Nikolaevna Ilina
Keyword(s):  
Population Change ◽  
Natural Populations ◽  
Average Density ◽  
Effective Density ◽  
Anthropogenic Factors ◽  
Efficiency Criterion ◽  
Protection Measures ◽  
Additional Protection ◽  
Geographical Populations ◽  
Satisfactory State

This paper examines features of the demographic structure of natural populations of a rare representative of the steppe flora Astragalus cornutus Pall. (Fabaceae). The rarity of the species makes it necessary to include it in the Red Books of the Russian Federation and some steppe regions. In the Samara Region, species populations require additional protection in connection with the peculiarities of biology and ecology, a significant anthropogenic load on communities, and a reduction in the number of habitats. We studied the features of the structure of populations in the Samara Trans-Volga Region. A total of 84 cenopopulations were surveyed, tendencies of population change, features of demographic and spatial structure were revealed. The structure of populations is affected by the ecological and phytocenotic conditions of the environment and anthropogenic factors. The replacement and recovery of individuals in A. cornutus populations is slow. The ontogenetic structure of populations has a fluctuation dynamics. Assessment of the studied geographical populations by L.A. Zhivotovsky efficiency criterion (2001) showed that they are all mature. Specific cenopopulations of A. cornutus are aging (5%) and old (8%). The average density of individuals is about 3 individuals/m. The average effective density is 2,4 individuals/m, the largest - 4,1, the smallest - 1,3. The condition of all studied populations (even in a satisfactory state) on the territory of the Samara Region causes alarm. Populations of the species in the region need additional protection measures.

scholarly journals Primer Binding Site (PBS) Profiling of Genetic Diversity of Natural Populations of Endemic Species Allium ledebourianum Schult.

BioTech ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 23
Author(s):  
Oxana Khapilina ◽  
Ainur Turzhanova ◽  
Alevtina Danilova ◽  
Asem Tumenbayeva ◽  
Vladislav Shevtsov ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Endemic Species ◽  
Biological Diversity ◽  
Natural Populations ◽  
Subsequent Development ◽  
Dna Profiling ◽  
Primer Binding Site ◽  
Anthropogenic Factors ◽  
Habitat Specificity ◽  
Interspersed Repeats

Endemic species are especially vulnerable to biodiversity loss caused by isolation or habitat specificity, small population size, and anthropogenic factors. Endemic species biodiversity analysis has a critically important global value for the development of conservation strategies. The rare onion Allium ledebourianum is a narrow-lined endemic species, with natural populations located in the extreme climatic conditions of the Kazakh Altai. A. ledebourianum populations are decreasing everywhere due to anthropogenic impact, and therefore, this species requires preservation and protection. Conservation of this rare species is associated with monitoring studies to investigate the genetic diversity of natural populations. Fundamental components of eukaryote genome include multiple classes of interspersed repeats. Various PCR-based DNA fingerprinting methods are used to detect chromosomal changes related to recombination processes of these interspersed elements. These methods are based on interspersed repeat sequences and are an effective approach for assessing the biological diversity of plants and their variability. We applied DNA profiling approaches based on conservative sequences of interspersed repeats to assess the genetic diversity of natural A. ledebourianum populations located in the territory of Kazakhstan Altai. The analysis of natural A. ledebourianum populations, carried out using the DNA profiling approach, allowed the effective differentiation of the populations and assessment of their genetic diversity. We used conservative sequences of tRNA primer binding sites (PBS) of the long-terminal repeat (LTR) retrotransposons as PCR primers. Amplification using the three most effective PBS primers generated 628 PCR amplicons, with an average of 209 amplicons. The average polymorphism level varied from 34% to 40% for all studied samples. Resolution analysis of the PBS primers showed all of them to have high or medium polymorphism levels, which varied from 0.763 to 0.965. Results of the molecular analysis of variance showed that the general biodiversity of A. ledebourianum populations is due to interpopulation (67%) and intrapopulation (33%) differences. The revealed genetic diversity was higher in the most distant population of A. ledebourianum LD64, located on the Sarymsakty ridge of Southern Altai. This is the first genetic diversity study of the endemic species A. ledebourianum using DNA profiling approaches. This work allowed us to collect new genetic data on the structure of A. ledebourianum populations in the Altai for subsequent development of preservation strategies to enhance the reproduction of this relict species. The results will be useful for the conservation and exploitation of this species, serving as the basis for further studies of its evolution and ecology.

scholarly journals The benefits of using topographic features to predict climate-resilient habitat for migratory forest landbirds: An example for the Rusty Blackbird, Olive-sided Flycatcher, and Canada Warbler

The Condor ◽  
2020 ◽  
Vol 122 (1) ◽  
Author(s):  
Shannon Bale ◽  
Karen F Beazley ◽  
Alana Westwood ◽  
Peter Bush
Keyword(s):  
Nova Scotia ◽  
Species Distribution ◽  
Habitat Suitability ◽  
Strong Association ◽  
Breeding Habitat ◽  
Important Predictor ◽  
Suitable Habitat ◽  
Topographic Features ◽  
Precipitation Regimes ◽  
Rusty Blackbird

Abstract Maintaining a functionally connected network of high-quality habitat is one of the most effective responses to biodiversity loss. However, the spatial distribution of suitable habitat may shift over time in response to climate change. Taxa such as migratory forest landbirds are already undergoing climate-driven range shifts. Therefore, patches of climate-resilient habitat (also known as “climate refugia”) are especially valuable from a conservation perspective. Here, we performed maximum entropy (Maxent) species distribution modeling to predict suitable and potentially climate-resilient habitat in Nova Scotia, Canada, for 3 migratory forest landbirds: Rusty Blackbird (Euphagus carolinus), Olive-sided Flycatcher (Contopus cooperi), and Canada Warbler (Cardellina canadensis). We used a reverse stepwise elimination technique to identify covariates that influence habitat suitability for the target species at broad scales, including abiotic (topographic control of moisture and nutrient accumulation) and biotic (forest characteristics) covariates. As topography should be relatively unaffected by a changing climate and helps regulate the structure and composition of forest habitat, we posit that the inclusion of appropriate topographic features may support the identification of climate-resilient habitat. Of all covariates, depth to water table was the most important predictor of relative habitat suitability for the Rusty Blackbird and Canada Warbler, with both species showing a strong association with wet areas. Mean canopy height was the most important predictor for the Olive-sided Flycatcher, whereby the species was associated with taller trees. Our models, which comprise the finest-scale species distribution models available for these species in this region, further indicated that, for all species, habitat (1) remains relatively abundant and well distributed in Nova Scotia and (2) is often located in wet lowlands (a climate-resilient topographic landform). These findings suggest that opportunities remain to conserve breeding habitat for these species despite changing temperature and precipitation regimes.

scholarly journals Distribution and abundance of baling twine in the landscape near Osprey (Pandion haliaetus) nests: implications for nestling entanglement

2014 ◽  
Vol 128 (2) ◽  
pp. 173 ◽  
Author(s):  
Renee Seacor ◽  
Kayhan Ostovar ◽  
Marco Restani
Keyword(s):  
Buffer Zone ◽  
Urban Landscapes ◽  
Pandion Haliaetus ◽  
Short Term ◽  
Road Density ◽  
Buffer Zones ◽  
Yellowstone River ◽  
Power Company ◽  
Breeding Seasons ◽  
High Road

Polypropylene baling twine used by Ospreys (Pandion haliaetus) during nest construction creates a risk of entanglement for nestlings and adults on the yellowstone River, Montana. In 2013, we evaluated the abundance of twine in 2-km-radius buffer zones centred on 38 nests for three categories of road density. We found more twine per kilometre along roads in low (n = 19) and moderate (n = 13) road density nest buffer zones than in high road density nest buffer zones (n = 6). The estimated total amount of twine found along roads in nest buffer zones ranged from 0 to 2602 m and did not differ among road density strata. The percentage of Osprey nests containing twine was highest in low (63.2%) and moderate (61.5%) road density nest buffer zones and lowest (33.3%) in high road density buffer zones, which reflected a gradient from rural and suburban to urban landscapes. The estimated total amount of twine within a nest buffer zone did not predict whether a nest contained twine. The amount of twine found in seven nests destroyed by wind or power company personnel ranged from 0 to 206 m and was not correlated with the amount of twine found in their buffer zones. During the 2012 and 2013 breeding seasons, four of 120 nestlings (3.3%) became entangled in twine: two were cut free and fledged normally, one died, and one was euthanized. The abundance of twine in the environment surrounding nests and its slow rate of biodegradation mean that vigilance by citizen scientist nest monitors and assistance from power companies are the only short-term solution to reducing mortality resulting from entanglement.

Classifying forestland from model-generated tree species habitat suitability in the Western Ecoregion of Nova Scotia, Canada

2013 ◽  
Vol 43 (6) ◽  
pp. 517-527 ◽  
Author(s):  
Mark Baah-Acheamfour ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng ◽  
D. Edwin Swift
Keyword(s):  
Nova Scotia ◽  
Tree Species ◽  
Habitat Suitability ◽  
Sugar Maple ◽  
Forest Succession ◽  
Red Maple ◽  
White Birch ◽  
Permanent Sample Plots ◽  
Natural Range ◽  
Hybrid Classification

Forestland classification is central to the sustainable management of forests. In this paper, we explore the possibility of classifying forestland from species–habitat–suitability indices and a hybrid classification of modeled data. Raster-based calculations of species–habitat–suitability were derived as a function of landscape-level descriptions of incident photosynthetically active radiation (PAR), soil water content (SWC), and growing degree-days (GDD) for southwestern Nova Scotia, Canada. PAR and SWC were both generated with the LanDSET model and GDD from thermal data captured with the space-borne MODIS sensor. We compared the distribution of predicted forestland types with the natural range of target species as found in the provincial permanent sample plots (PSPs). Reasonable agreement (≥50% accuracy) existed between some forestland types (e.g., red maple – white birch – red oak and balsam fir – red maple) and PSP-based assessments of species presence–absence. Agreement was noticeably lower for other forestland types, such as sugar maple – beech – yellow birch (<50% accuracy). This discrepancy is attributed to forest-forming factors not directly addressed by the model, e.g., forest succession, stand interventions, and disturbance. Their addition in the model could change the dynamics of tree-species preference in southwest Nova Scotia and is worth examining. True model inaccuracies accounted for about 0.3%–15.0% of the total reported error.

Aquatic hyphomycete spora in 10 streams of New Brunswick and Nova Scotia

1987 ◽  
Vol 65 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Felix Bärlocher
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Negative Correlation ◽  
Sampling Technique ◽  
Significant Negative Correlation ◽  
Fungal Species ◽  
Aquatic Hyphomycetes ◽  
Species Number ◽  
Chemical Parameters ◽  
Rapid Loss

Aquatic hyphomycete communities of 10 soft-water streams in Nova Scotia and New Brunswick were investigated with a foam sampling technique. The number of identifiable species varied between 26 and 42. Alkalinity, conductance, pH, and content of Ca2+, Mg2+, Na+, and K+ were measured in all streams. No significant correlation was found between number of fungal species and any of the chemical parameters. Combining the data with those of an earlier study revealed a significant, negative correlation between species number of a stream and its pH. The number of aquatic hyphomycetes appears to decline slowly, if at all, between 5 and 7. This is followed by a more rapid loss at values above 7.

scholarly journals SIMULATION OF SPATIAL DISTRIBUTION OF RARE SPECIES IN PROTECTED NATURAL AREAS (ON THE EXAMPLE OF THE CENTRAL FOREST RESERVE, RUSSIA)

2019 ◽  
Vol 1 ◽  
pp. 75
Author(s):  
Anatoly Istomin ◽  
Sergey Mikhalap
Keyword(s):  
Spatial Distribution ◽  
Habitat Suitability ◽  
Rare Species ◽  
Vegetation Type ◽  
Biosphere Reserve ◽  
Entropy Method ◽  
Natural Areas ◽  
Forest Reserve ◽  
Integral Characteristics ◽  
Protected Natural Areas

An important task of modern ecology is the modeling of the spatial distribution of organisms. Of particular relevance is the modeling of the distribution of rare species in protected natural areas. The paper discusses the main stages and presents the results of modeling the habitat suitability of the Central Forest State Nature Biosphere Reserve (Russia, Tver region) for the red vole. This species is a rare and relict for the center of the Caspian-Baltic watershed. In the modelling the maximum entropy method (MaxEnt) was used. The basis for building the model was the field sampling of the authors, performed in July-August 2010-2014. Each year, trapping were carried out at 745 sampling points each of which has geographical referencing in the WGS 84. A total of 12238 trap-days were worked out and 141 red vole individuals were caught. In the process of modeling, the contribution to the species distribution of certain integral characteristics of habitats (relief, vegetation type and three vegetation spectral indices) was determined. A map model of habitat suitability for the red vole on the territory of the Reserve was built, which allowed to describe the spatial structure of the population groups of the species. The total areas of the most favorable sites for the habitat of the red vole on the reserve's territory were calculated.

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