Ştefan R. Zamfirescu

Refining Climate Change Projections for Organisms with Low Dispersal Abilities: A Case Study of the Caspian Whip Snake

Climate warming is one of the most important threats to biodiversity. Ectothermic organisms such as amphibians and reptiles are especially vulnerable as climatic conditions affect them directly. Ecological niche models (ENMs) are increasingly popular in ecological studies, but several drawbacks exist, including the limited ability to account for the dispersal potential of the species. In this study, we use ENMs to explore the impact of global climate change on the Caspian whip snake (Dolichophis caspius) as model for organisms with low dispersal abilities and to quantify dispersal to novel areas using GIS techniques. Models generated using Maxent 3.3.3 k and GARP for current distribution were projected on future climatic scenarios. A cost-distance analysis was run in ArcGIS 10 using geomorphological features, ecological conditions, and human footprint as “costs” to dispersal of the species to obtain a Maximum Dispersal Range (MDR) estimate. All models developed were statistically significant (P<0.05) and recovered the currently known distribution of D. caspius. Models projected on future climatic conditions using Maxent predicted a doubling of suitable climatic area, while GARP predicted a more conservative expansion. Both models agreed on an expansion of suitable area northwards, with minor decreases at the southern distribution limit. The MDR area calculated using the Maxent model represented a third of the total area of the projected model. The MDR based on GARP models recovered only about 20% of the total area of the projected model. Thus, incorporating measures of species’ dispersal abilities greatly reduced estimated area of potential future distributions.

Population characteristics of the adder (Vipera berus berus) in the Northern Romanian Carpathians with emphasis on colour polymorphism: is melanism always adaptive in vipers?

The adaptive significance of melanism and the hypotheses regarding the maintenance of colour polymorphism in snake populations have been the subject of numerous studies and great controversies over the years. The present paper aims to present the first data on population characteristics of the adder (Vipera berus berus – one of the taxa most frequently used as model organism in studies on colour polymorphism) from the Carpathian Mountains, with emphasis on the frequency of melanistic individuals and comparison of body size between the two morphs. A short review of the frequency of melanistic individuals in populations described by previous studies is also presented. Given the fact that melanistic individuals were infrequent in this population, that no significant differences were detected with regards to the body size of the two morphs, and the supporting literature, we conclude that maintenance of colour polymorphism in this population might result from non-adaptive processes, having no or very little adaptive value.

A preliminary study on population characteristics and ecology of the critically endangered meadow viper Vipera ursinii in the Romanian Danube Delta

The present paper discusses preliminary data on population characteristics and ecology of the meadow viper Vipera ursinii in the Romanian Danube Delta. Using line transects and the Distance software, the size of the studied population was estimated at 321 (95% confidence interval: 166–618) individuals on a 62 ha area. The sex-ratio of the population was close to 1:1 and juvenile specimens were well represented. Half of the captured adult females were gravid, possibly indicating a more than annual reproductive cycle. Analysis of sexual dimorphism of 12 morphometric traits indicated significant differences only in tail length and height. No significant relationships were detected between the size, sex, age or reproductive status and the thermal ecology of the vipers. Microhabitat selection and activity patterns varied with age, sex and reproductive status and are probably linked to an onthogenetic shift in feeding ecology and to behavioral differences between reproductive and non-reproductive females.

Forest Communities Floristically Specific to Eastern Romania

A series of forest communities from the eastern part of Romania (Moldova) are presented synthetically. Phytosociologically, these communities appertain to the following associations: Aro orientalis - Carpinetum (Dobrescu et Kovacs 1973) Tauber 1992 (typicum subass. nova hoc loco; quercetosum pedunculiflorae Chifu et al. 2002); Dentario quinquefoliae - Carpinetum (Dobrescu et Kovacs 1973) Tauber 1992 (typicum Chifu et Zamfirescu 2001; fraxinetosum excelsioris Chifu et Zamfirescu 2001); Lathyro veneti - Fagetum (Dobrescu et Kovacs 1973) Chifu 1995 (typicum (Chifu 1995) Chifu et Zamfirescu 2001; quercetosum dalechampii (Chifu 1995) Chifu et al. 1999). Floristic analysis reveals the dominance of Pontic and Balkan elements compared to Central European species. The reason for this pattern is the location of the studied communities in the zone where Central European and Pontico-South-Siberian regions overlap. Based on the similarity between them, the releves studied fall into three clusters that correspond to the three above-mentioned associations of the same coenotaxon - suballiance Aro orientalis - Carpinion. The grouping of Lathyro veneti - Fagetum with Dentario quinquefoliae - Carpinetum releves results from the overlapping altitudinal distribution of the two forest types. Quercus dalechampii dominance-abundance scores distinguish the communities of Dentario quinquefoliae - Carpinetum, whereas Fraxinus excelsior discriminates between the two subassociations. The communities belonging to Aro orientalis - Carpinetum distinguish themselves through the high cover scores of Quercus robur and Q. pedunculiflora. Furthermore, Quercus pedunculiflora has higher cover scores in southern releves (Vaslui County), whereas Q. robur dominates in the northern releves (Iasi County). The group of releves of Lathyro veneti - Fagetum is clearly discriminated by the high cover of Fagus sylvatica.

Annual Reproduction in Female Adders (Vipera berus) from a Montane Environment

Abstract European vipers are typical capital breeders and most studies have revealed that females usually reproduce once every two or three years and that, in some cases, females reproduce once during their lifetime. This paper presents evidence, based on monitoring marked snakes in consecutive years, that several female adders (Vipera berus) from a montane environment from the Northern Romanian Carpathians reproduced annually (2007–2008), and also gives preliminary data on other female reproductive traits. Reproductive females and their offspring were smaller and lighter than V. berus individuals from most previously studied populations. Maternal traits were not significantly correlated with litter and offspring characteristics.

New Records for the Aesculapian Snake (Zamenis longissimus) (Reptilia: Colubridae) in Romanian Moldova

Abstract The Aesculapian snake (Zamenis longissimus) is a widespread colubrid species, being present in much of central and southern Europe, with isolated populations occuring as far east as Iran. In Romania, the species is known from most of the country’s regions, although it has been reported from very few areas from the Moldova region (eastern and north–eastern Romania). Here we present three new records for Z. longissimus in Romanian Moldova, including the first record for the species in Botoșani County, the north–easternmost region of Romania.