Search results for "CONSERVATION"

Habitat preferences of edible dormouse, Glis glis italicus: implications for the management of arboreal mammals in Mediterranean forests

2015

Research on arboreal mammals living in Mediterranean forests is poor. Molecular research assessed the existence of an evolutionary significant unit in the edible dormouse populations living in south Italy, Sicily and Sardinia, and we decided to investigate the environmental factors capable of explaining its occurrence and abundance in Sicily, for a better management of these populations. We assessed the species habitat preferences by setting 25 large and 25 small nestboxes in five sample areas along an altitudinal gradient of the Madonie Range, and recorded habitat variables, food availability, and demographic data for two years. To obtain synthetic descriptors of the dormice habitat requir…

2020

Piping erosion is one form of water erosion that leads to significant changes in the landscape and environmental degradation. In the present study, we evaluated piping erosion modeling in the Zarandieh watershed of Markazi province in Iran based on random forest (RF), support vector machine (SVM), and Bayesian generalized linear models (Bayesian GLM) machine learning algorithms. For this goal, due to the importance of various geo-environmental and soil properties in the evolution and creation of piping erosion, 18 variables were considered for modeling the piping erosion susceptibility in the Zarandieh watershed. A total of 152 points of piping erosion were recognized in the study area that…

Genetic variability in a narrow endemic snapdragon (Antirrhinum subbaeticum, Scrophulariaceae) using RAPD markers

2002

Antirrhinum subbaeticum is an endangered species inhabiting fragmented limestone cliffs. In the last 3 years, a drastic population decline has been observed in three of four known populations and the estimated number of surviving individuals is now close to 400. A RAPD study was conducted to evaluate the levels of genetic variation present in this species to improve conservation guidelines. Thirty-nine polymorphic products identified 66.1% of the samples by unique RAPD multilocus profiles. A cluster analysis grouped the samples into two broad groups corresponding to northern or southern provenances. AMOVA analysis showed that only 17.7% of the genetic diversity was partitioned within popula…

Recolonization after habitat restoration leads to decreased genetic variation in populations of a terrestrial orchid.

2012

Colonization is crucial to habitat restoration projects that rely on the spontaneous regeneration of the original vegetation. However, as a previously declining plant species spreads again, the likelihood of founder effects increases through recurrent population founding and associated serial bottlenecks. We related Amplified Fragment Length Polymorphism markers genetic variation and fitness to colonization history for all extant populations of the outcrossing terrestrial orchid Dactylorhiza incarnata in an isolated coastal dune complex. Around 1970, D. incarnata suffered a severe bottleneck yet ultimately persisted and gradually spread throughout the spatially segregated dune slacks, aided…

RAD SNP markers as a tool for conservation of dolphinfish Coryphaena hippurus in the Mediterranean Sea: Identification of subtle genetic structure an…

2016

Dolphinfish is an important fish species for both commercial and sport fishing, but so far limited information is available on genetic variability and pattern of differentiation of dolphinfish populations in the Mediterranean basin. Recently developed techniques allow genome-wide identification of genetic markers for better understanding of population structure in species with limited genome information. Using restriction-site associated DNA analysis we successfully genotyped 140 individuals of dolphinfish from eight locations in the Mediterranean Sea at 3324 SNP loci. We identified 311 sex-related loci that were used to assess sex-ratio in dolphinfish populations. In addition, we identifie…

Genetic Diversity, Population Size, and Fitness in Central and Peripheral Populations of a Rare Plant Lychnis viscaria

1999

: Genetic diversity is expected to decrease in small and isolated populations as a consequence of bottlenecks, founder effects, inbreeding, and genetic drift. The genetics and ecology of the rare perennial plant Lychnis viscaria (Caryophyllaceae) were studied in both peripheral and central populations within its distribution area. We aimed to investigate the overall level of genetic diversity, its spatial distribution, and possible differences between peripheral and central populations by examining several populations with electrophoresis. Our results showed that the level of genetic diversity varied substantially among populations (  Hexp = 0.000–0.116) and that the total level of genetic …

Sex-Biased Inbreeding Effects on Reproductive Success and Home Range Size of the Critically Endangered Black Rhinoceros

2013

A central premise of conservation biology is that small populations suffer reduced viability through loss of genetic diversity and inbreeding. However, there is little evidence that variation in inbreeding impacts individual reproductive success within remnant populations of threatened taxa, largely due to problems associated with obtaining comprehensive pedigree information to estimate inbreeding. In the critically en- dangered black rhinoceros, a species that experienced severe demographic reductions, we used model selection to identify factors associated with variation in reproductive success (number of offspring). Factors examined as predictors of reproductive success were age, home ran…

Isozyme uniformity in a wild extinct insular plant,Lysimachia minoricensisJ.J. Rodr. (Primulaceae)

1999

Isozyme analyses were conducted to evaluate the genetic diversity of seed accessions of Lysimachia minoricensis (a Balearic endemic plant that became extinct in the wild) provided by 10 European botanical gardens. No isozyme variation was detected after examination of the electrophoretic patterns of 22 putative loci in more than 150 plants. The lack of genetic variation in L. minoricensis is probably due to the shortage of sample propagules originally recovered in the field before its extinction. Extant plants of L. minoricensis are believed to have originated from a single source, therefore limiting their use as seed stocks for restoration projects.

Environmental effects on molecular and phenotypic variation in populations of Eruca sativa across a steep climatic gradient

2013

Abstract In Israel Eruca sativa has a geographically narrow distribution across a steep climatic gradient that ranges from mesic Mediterranean to hot desert environments. These conditions offer an opportunity to study the influence of the environment on intraspecific genetic variation. For this, we combined an analysis of neutral genetic markers with a phenotypic evaluation in common-garden experiments, and environmental characterization of populations that included climatic and edaphic parameters, as well as geographic distribution. A Bayesian clustering of individuals from nine representative populations based on amplified fragment length polymorphism (AFLP) divided the populations into a…

Founder population size and number of source populations enhance colonization success in waterstriders.

2002

Understanding the factors that underlie colonization success is crucial both for ecological theory and conservation practices. The most effective way to assess colonization ability is to introduce experimentally different sets of individuals in empty patches of suitable habitat and to monitor the outcome. We translocated mated female waterstriders, Aquarius najas, into 90 streams that were not currently inhabited by the species. We manipulated sizes of propagules (from 2 to 16 mated females) and numbers of origin populations (one or two). Three origin populations were genetically different from each other, but they were less than 150 km from the streams of translocation. The results demonst…