scholarly journals Contradicting habitat type-extinction risk relationships between living and fossil amphibians

2017 ◽  
Vol 4 (5) ◽  
pp. 170051 ◽  
Author(s):  
Melanie Tietje ◽  
Mark-Oliver Rödel
Keyword(s):  
Extinction Risk ◽  
Persistence Length ◽  
Habitat Type ◽  
Habitat Types ◽  
Amphibian Species ◽  
Terrestrial Vertebrates ◽  
Rivers And Streams ◽  
Fossil Data ◽  
Flowing Waters

Trait analysis has become a crucial tool for assessing the extinction risk of species. While some extinction risk-trait relationships have been often identical between different living taxa, a temporal comparison of fossil taxa with related current taxa was rarely considered. However, we argue that it is important to know if extinction risk-trait relations are constant or changing over time. Herein we investigated the influence of habitat type on the persistence length of amphibian species. Living amphibians are regarded as the most threatened group of terrestrial vertebrates and thus of high interest to conservationists. Species from different habitat types show differences in extinction risk, i.e. species depending on flowing waters being more threatened than those breeding in stagnant sites. After assessing the quality of the available amphibian fossil data, we show that today's habitat type-extinction risk relationship is reversed compared to fossil amphibians, former taxa persisting longer when living in rivers and streams, thus suggesting a change of effect direction of this trait. Neither differences between amphibian orders nor environmentally caused preservation effects could explain this pattern. We argue this change to be most likely a result of anthropogenic influence, which turned a once favourable strategy into a disadvantage.

scholarly journals Variation in Deadwood Microsites in Areas Designated under the Habitats Directive (Natura 2000)

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 486
Author(s):  
Leszek Bujoczek ◽  
Stanisław Zięba ◽  
Małgorzata Bujoczek
Keyword(s):  
Logistic Regression ◽  
Regression Model ◽  
Logistic Regression Model ◽  
Habitat Type ◽  
Natura 2000 ◽  
Habitats Directive ◽  
Managed Forests ◽  
Habitat Types ◽  
Living Tree

The continuing decline in biodiversity presents a major environmental protection challenge. The conservation of sufficiently extensive and diverse habitats requires an array of coordinated actions, often involving large areas. While a set of conservation objectives have been defined for the Natura 2000 network, no universal methods of accomplishing them have been specified, and so they must be designed by individual Member States. Deadwood volume and the density of large deadwood pieces are widely used for evaluating the quality of forest habitat types designated under the Habitats Directive. In the present study, data from 5557 sample plots were used to evaluate the mean values of the two deadwood indicators as well as the ratio of deadwood volume to living tree volume for each of the 13 habitat types in Poland. In addition, a logistic regression model was constructed to evaluate the effects of terrain, site, and tree stand characteristics as well as protection type on deadwood volume in Natura 2000 areas. Mean deadwood volume varied greatly between habitat types, with the lowest values found for Central European lichen Scots pine forests (91T0–2.5 m3 ha−1) and Old acidophilous oak woods (9190–4.4 m3 ha−1), and the highest for Riparian mixed forests (91F0–43.1 m3 ha−1) and Acidophilous Picea forests of the montane to alpine levels (9410–55.4 m3 ha−1). The ratio of deadwood volume to living tree volume ranged from approx. 1%–17%. Additionally, the presence of large deadwood differed among habitat types: in some, there were no deadwood pieces with a diameter of ≥50 cm, while their maximum density was 6.1 pieces ha−1. The logistic regression model showed that the likelihood of a habitat type to have a ‘favorable conservation status’ as defined by deadwood abundance (a threshold of at least 20 m3 ha−1 according to Polish manuals on habitat type evaluation) increased with sample plot elevation, site fertility, and moisture, as well as stand age and volume. Positive effects were also observed for forests under strict and active protection versus managed forests. Planned efforts are necessary to enhance the quality of habitats with insufficient deadwood, especially in managed forests. Special attention should be given to areas that are readily accessible due to gentle terrain and low site moisture. Furthermore, younger stands on less fertile sites may require intervention to promote deadwood accumulation. We recommend retaining a certain proportion of mature stands until natural death and decomposition. Increasing the density of large deadwood is currently one of the most pressing conservation needs in most habitat types.

scholarly journals Do the assemblages of benthic macroinvertebrates in nearshore waters of Western Australia vary among habitat types, zones and seasons?

2005 ◽  
Vol 85 (2) ◽  
pp. 217-232 ◽  
Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Habitat Type ◽  
Abundant Species ◽  
Subtidal Zone ◽  
Habitat Types ◽  
Environmental Characteristics ◽  
Deposit Feeding ◽  
Number Of Individuals

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.

scholarly journals Synergistic impacts of global warming and thermohaline circulation collapse on amphibians

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Julián A. Velasco ◽  
Francisco Estrada ◽  
Oscar Calderón-Bustamante ◽  
Didier Swingedouw ◽  
Carolina Ureta ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Thermohaline Circulation ◽  
Climate Model ◽  
Global Climate ◽  
Extinction Risk ◽  
Meridional Overturning Circulation ◽  
Mitigation Strategies ◽  
Amphibian Species ◽  
Climate Conditions

AbstractImpacts on ecosystems and biodiversity are a prominent area of research in climate change. However, little is known about the effects of abrupt climate change and climate catastrophes on them. The probability of occurrence of such events is largely unknown but the associated risks could be large enough to influence global climate policy. Amphibians are indicators of ecosystems’ health and particularly sensitive to novel climate conditions. Using state-of-the-art climate model simulations, we present a global assessment of the effects of unabated global warming and a collapse of the Atlantic meridional overturning circulation (AMOC) on the distribution of 2509 amphibian species across six biogeographical realms and extinction risk categories. Global warming impacts are severe and strongly enhanced by additional and substantial AMOC weakening, showing tipping point behavior for many amphibian species. Further declines in climatically suitable areas are projected across multiple clades, and biogeographical regions. Species loss in regional assemblages is extensive across regions, with Neotropical, Nearctic and Palearctic regions being most affected. Results underline the need to expand existing knowledge about the consequences of climate catastrophes on human and natural systems to properly assess the risks of unabated warming and the benefits of active mitigation strategies.

scholarly journals Recent Invasion of the Endemic Banggai Cardinalfish, Pterapogon kauderni at The Strait of Bali: Assessment of the Habitat Type and Population Structure

2019 ◽  
Vol 24 (1) ◽  
pp. 15 ◽  
Author(s):  
I Nyoman Giri Putra ◽  
I Dewa Nyoman Nurweda Putra
Keyword(s):  
Natural Habitat ◽  
Habitat Type ◽  
Marine Organisms ◽  
Aquarium Trade ◽  
Small Populations ◽  
Depth Range ◽  
Habitat Types ◽  
Weight Relationship ◽  
Narrow Bay ◽  
Sexually Mature

The demands of marine organisms for the aquarium trade are remain high and seems continue to increase. Consequently, many of marine organisms has been spread out from its natural habitat as in the case of endemic Banggai cardinalfish, (Pterapogon kauderni). That has invaded “new” habitat since it being trade in 1995. In recent years, a small populations of P. kauderni is known to be exist in a narrow bay near the Gilimanuk harbor, Bali. An underwater visual fish census survey was conducted on June 2018 to estimate the habitat types and densities of P. kauderni.  Additionally, 23 specimens of P. kauderni were collected randomly in order to assess biological parameters such as the length-weight relationship. We successfully recorded 30 groups of P. kauderni that inhabit a shallow areas with a depth range between 0.5m to 2m. Of these, more than 90% of the groups were found to be associated with sea urchin (Diadema sp.) while the rest were found to live together with branching coral (Acropora sp.) and branching sponge (Ptylocaulis sp.). Total number of fish observed during the survey were 381 individuals. The fish density is 0.76 individu.m-2. Length-weight relationship showed that P. kauderni exhibit is negative allometry (b<3) which mean that the increase in length is faster than the weight gain. Interestingly, from the 23 specimens collected, none of these were sexually mature (SL<41 mm) which may indicated that the population of P. kauderni in Bali are under serious threats of exploitation.     

scholarly journals Development and evaluation of an automated system for testing current meters

2016 ◽  
Vol 20 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Ezequiel Saretta ◽  
Antonio P. de Camargo ◽  
Tarlei A. Botrel ◽  
Marinaldo F. Pinto ◽  
Geancarlo T. Katsurayama ◽  
...  
Keyword(s):  
User Interface ◽  
Data Acquisition ◽  
Flow Velocity ◽  
Reference Value ◽  
Vertical Axis ◽  
Automated System ◽  
Step Motor ◽  
Simple Task ◽  
Rivers And Streams

ABSTRACT Current meters are equipment widely used for estimating flow velocity in rivers and streams. Periodic calibrations of current meters are important to ensure the quality of measurements, but the required testing facilities are complex and only available in a few institutions. However, advances in electronics and automation may contribute to developing simple and reliable calibration systems. Thus, this study aimed to develop an automated system for testing current meters, which consisted of a trapezoidal channel, a step motor, a tow car and a management system, composed of a supervisory application and microprocessed modules to control the motor and the data acquisition. Evaluations of the displacement velocity showed that it matched the reference value up to 1.85 m s-1 for a vertical-axis current meter and 2.3 m s-1 for a horizontal-axis one. The developed system showed reliability during tests, for both current meter movement and data acquisition. The management of the system based on the developed modules and the supervisory application improved its user interface, turning all the procedure into a simple task.

scholarly journals Diet of otters (Lutra lutra) in various habitat types in the Pannonian biogeographical region compared to other regions of Europe

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2266 ◽  
Author(s):  
József Lanszki ◽  
István Lehoczky ◽  
Antoinette Kotze ◽  
Michael J. Somers
Keyword(s):  
Habitat Type ◽  
Hierarchical Cluster ◽  
Trophic Niche ◽  
Lutra Lutra ◽  
Fish Diet ◽  
Fish Farms ◽  
Habitat Types ◽  
Mediterranean Regions ◽  
Biogeographical Region ◽  
Study Sites

Knowledge of the effect of habitat type and region on diet and feeding behaviours of a species facilitates a better understanding of factors impacting populations, which contributes to effective conservation management. Using spraint analysis and relative frequency of occurrence data from the literature, we described the dietary patterns of Eurasian otters (Lutra lutra) in 23 study sites within the Pannonian biogeographical region in Hungary. Our results indicated that diet composition varied by habitat type and is therefore context dependant. The differences among habitat types were however lower than expected. We noticed a decline in the fish consumption with a concomitant increase in trophic niche breadth and amphibian consumption in rivers, ponds (fish farms), backwaters, marshes and small watercourses. The main differences in diet were not attributed to the consumption of primary and secondary food types (fish and amphibians), but rather to differences in other, less important food types (mammals, birds). Using hierarchical cluster analysis, rivers and ponds could clearly be separated from other habitat types. We found the main fish diet of otters in most of these areas consisted of small (<100 g), eurytopic, littoral and non-native, mostly invasive species. Dietary studies from 91 sites in six European biogeographical regions showed that fish are consumed most frequently in the Atlantic and Boreal, less in the Continental and Pannonian, and least in the Alpine and Mediterranean regions. Comparative analysis indicated that the Mediterranean region (with frequent crayfish consumption) and Alpine region (frequent amphibian consumption) cluster separate from the other regions.

scholarly journals INFORMATION MATERIALS ON THE PROTECTION OF DAYTIME LEPIDOPTERA (LEPIDOPTERA: HESPERIOIDEA, PAPILIONOIDEA) OF UDMURTIA: ANALYSIS OF THREATS AND LIMITING FACTORS OF SPECIES’ EXISTENCE

2019 ◽  
Vol 29 (3) ◽  
pp. 337-345
Author(s):  
D.A. Adakhovskiy
Keyword(s):  
Limiting Factors ◽  
Nature Management ◽  
Habitat Types ◽  
Factors Affecting ◽  
Population Structures ◽  
Potential Risks ◽  
Information Materials ◽  
Regional Types ◽  
Degree Of Fragmentation

The article summarizes the materials on the set of limiting criteria and factors affecting the group of threatened species of diurnal Lepidoptera of Udmurtia. The group is formed by representatives belonging to the categories "Exposed to critical danger", "Endangered" and "Vulnerable", allocated by the regional co-Zoological analysis of the fauna of Rhopalocera. A set of criteria used to identify the threatened categories includes the following indicators of limitation: arealographic (total breadth of distribution of species in the region, the degree of fragmentation of regional habitat types, trends in regional species' chorology); biotopic (quantity and quality of key habitats in the region, as well as actual and potential risks and declining trends in their quantity and quality); population (the level of localization of population structures of species). The main factors of anthropogenic impact on the habitats of moths include the regional types of nature management with landscape-scale manifestations, such as agricultural and forestry activities.

scholarly journals Use of summer habitat by caribou on the north slope of a mountain near the Macmillan Pass, N.W.T.

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 311 ◽  
Author(s):  
James F. Quayle ◽  
G. Peter Kershaw
Keyword(s):  
Habitat Type ◽  
Indirect Evidence ◽  
High Elevation ◽  
North Slope ◽  
Habitat Types ◽  
The North ◽  
Feeding Cycle ◽  
Alpine Habitats ◽  
Pellet Density ◽  
Insect Harassment

Habitat use by woodland caribou was investigated by counting pellet-groups, sampling phytomass, and evaluating topography in nine habitat-types on the north slope of an unnamed mountain near Macmillan Pass, N.W.T. Caribou pellets were most abundant in high elevation habitat-types, and pellet density was greatest in an alpine Lichen-Grass habitat-type with a slope of &lt;1&deg;. The high density of pellets in alpine areas may have resulted from of the use of cool, windy, alpine habitats by caribou seeking relief from insect harassment. There were no apparent relationships between pellet abundance, and phytomass of mosses, lichens, or graminoids, possibly as a result of caribou feeding and defecating in different habitats. The occurrence of pellets with a coalesced morphology in the barren Lichen-Grass habitat-type provided indirect evidence in support of a feeding cycle, whereby caribou visit lush habitats to feed, and return to open, alpine habitats to rest and ruminate.

scholarly journals Effect of Climate and Habitat on Morphological Characteristics and Fruit Production of Picralima Nitida (Stapf) in West Africa

2021 ◽  
Author(s):  
Ghislain Comlan AKABASSI ◽  
Elie Antoine Padonou ◽  
Achille Ephrem Assogbadjo ◽  
Noël Zirihi Guede
Keyword(s):  
Pearson Correlation ◽  
Habitat Type ◽  
Morphological Characteristics ◽  
Botanical Garden ◽  
Fruit Production ◽  
Natural Forest ◽  
Home Gardens ◽  
Suitable Habitat ◽  
Habitat Types ◽  
Pharmaceutical Industries

Abstract Picralima nitida is an important African medicinal plant species used in pharmaceutical industries and traditional medicine to treat several diseases. Despite its importance, the species faces conservation problem. This study evaluated the effect of climate and habitat on morphological characteristics and fruit production of P. nitida. A total of 132 fruiting trees was randomly sampled from three habitat types (home gardens, botanical garden and natural forest) and three soils (Nitisols, Arenosols and Acrisols) in Dahomey Gap and Guineo-Congolese zone. A total of 5 morphological traits and fruit production were recorded per tree to describe the relationship between morphological determinism of the species and climate. Pearson correlation was performed to identify the suitable habitat type in each climatic zone. Harmonized World Soil Database was used to determine physicochemical characteristics of the soil types on which the species occurred. Results revealed that the climatic zones (p < 0.001) and habitat types (p < 0.0001) influenced significantly the morphological characteristics and fruit production of P. nitida. High trees with more number of fruits were observed in home gardens on acid soils (Nitisols (pH: 5) and Arenosols (pH: 5.3)) in Dahomey Gap. In Guineo-Congolese zone, the species was more present in natural forest on acid Acrisols (pH: 5).

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