Browse results

Izabella Olejniczak and Stanisław Lenart

In 2009 and 2010, we examined the effects of different tillage systems on springtail communities. The study was established on the experimental field, in which tillage and no-tillage cultivation had been conducted since 1975, of the Research Station of the Warsaw University of Life Sciences’ Department of Agronomy, located at Chylice, near Warsaw (52005’N, 20033’E).

The treatments considered were conventional tillage with a mouldboard plough (CT) and no-tillage (NT), and each method was divided between with and without liming. In 2009, the fields were sown with winter wheat, and spring barley was planted the following year. During both growing seasons, collembolan densities were higher under NT than CT, but the reverse was true after harvest. However, the time of the season had a significant effect on collembolan densities not only over the whole study period but also in particular years. Additionally, in fields that were limed, collembolan densities varied, with no clear trend. The dominant collembolan species in the CT and NT fields was Isotoma viridis Bourlet, 1839, while Paristoma notabilis (Schäffer, 1896) was prevalent when liming was used. The relative proportion of each of the two species in springtail communities was at least 20 percent. The species diversity of collembolan communities was similar in both study years, and it was higher in CT than in NT fields.

The study was financially supported as part of the MNiSW project No. N N305171136.

Corrado Battisti, Marco Giardini, Francesca Marini, Lorena Di Rocco, Giuseppe Dodaro and Leonardo Vignoli

We reported a study on breeding birds occurring inside an 80 m-deep karst sinkhole, with the characterization of the assemblages recorded along its semi-vertical slopes from the upper edge until the bottom. The internal sides of the sinkhole have been vertically subdivided in four belts about 20 m high. The highest belt (at the upper edge of the cenote) showed the highest values in mean number of bird detections, mean and normalized species richness, and Shannon diversity index. The averaged values of number of detections and species richness significantly differ among belts. Species turnover (Cody’s β-diversity) was maximum between the highest belts. Whittaker plots showed a marked difference among assemblages shaping from broken-stick model to geometric series, and explicited a spatial progressive stress with a disruption in evenness towards the deepest belts. Bird assemblages evidenced a nested subset structure with deeper belts containing successive subsets of the species occurring in the upper belts. We hypothesize that, at least during the daytime in breeding season, the observed non-random distribution of species along the vertical stratification is likely due to (i) the progressive simplification both of the floristic composition and vegetation structure, and (ii) the paucity of sunlight as resources from the upper edge to the inner side of the cenote.

Hugh Lefcort and Burt P. Kotler

Abstract In addition to effects on climate and water acidification, anthropogenic atmospheric releases of carbon dioxide may also directly impact terrestrial organisms that use CO2 as a chemical cue. We wondered how common organisms would respond to near-future levels of CO2 – levels that may occur by 2025. We chose two common but taxonomically and ecologically dissimilar organisms (Theba pisana helicid snails and Adesmia dilatata tenebrionid beetles) to examine the behavioral effects of a slight rise (~10 ppm) of CO2 on animal abundance and plant growth in the Negev Desert of Israel. We found that plots with supplementary CO2 exhibited greater plant growth than control plots over a 50-day experiment, but increased growth did not alter beetle or snail numbers.

In laboratory experiments with higher levels of augmented CO2 paired with food rewards, we found that snails did not change their climbing behavior when presented with CO2 alone, but they avoided food and climbed away when CO2 was paired with food. Beetles in the laboratory were attracted to food regardless of CO2 levels although high levels of CO2 (1200–1300 ppm) reduced movement.

The direct effects of near-future CO2 levels may augment plant growth but have only minor influence on terrestrial snails and beetles. However, the effects of CO2 on climate change in desert habitats like the Negev may be more severe due to a predicted rise in temperature and a decline in precipitation.

Yuval Itescu, Rachel Schwarz, Shai Meiri and Panayiotis Pafilis

We recently studied whether, on islands, predation or intraspecific aggression is the main driver of tail-loss, a common defense mechanism among lizards. We concluded the latter was the stronger driver (Itescu et al. 2017). Werner (2017) suggested that we failed to falsify an alternative hypothesis. He claims that on low-predation islands lizards live longer. Thus while tail loss is caused by predators, it accumulates over longer periods, resulting in overall higher tail-loss rates in populations experiencing weak predation. Here we test this hypothesis and three other arguments he presented, and fail to support them. We therefore adhere to our original conclusion that intraspecific aggression is the main driver of lizard tail loss on islands.

Myriam Freund, Ofer Bahat and Uzi Motro

We studied the use of nest-sites by Griffon Vultures (Gyps fulvus) and the breeding success in these sites during 1998–2002 in Gamla Nature Reserve (Israel). Nest-sites in which a breeding attempt succeeded in fledging a young, were more likely to be occupied by nesting vultures in the following breeding season, than nest-sites that experienced a failure. This suggests that Griffon Vultures in Gamla used a Win–Stay/Lose–Shift strategy regarding nest-site fidelity.

Mao Wang, Pengcheng Wan, Jiangchao Guo, Jinshi Xu, Yongfu Chai and Ming Yue

Leaves, stems and roots as the main plant organs have specific functions and together modulate survival, growth and reproduction. The relationships between these organs are high research priority, and there have been many hypotheses about the trade-offs between them. However, the results of these hypotheses are inconsistent and confusing. In this study, we examined 15 core traits of leaves, stems and woody roots of 27 dominant shrub species and further tested the hypotheses about the relationships between these organs. Measurements were made for shrubs across 9 sites including desert, steppe, temperate forest and subtropical forest in Shaanxi Province of China. Many significant correlations of different organ traits were found, e.g. nitrogen and phosphorus content showed a significant positive correlation, either within or across organs. Also, representatives of structural traits (carbon content and dry matter content) and mineral nutrient traits (nitrogen and phosphorus content) showed significant positive correlations among the leaves, stems and roots. The results of this study supported the hypotheses that there were significant correlations between leaf and root and between stem and root. Similarly, we found that trade-off between leaf and stem-plus-root showed a significant correlation. Thus, root traits, which are difficult to measure, are coordinated with those of the leaf and stem. We conclude that the leaf component of shrubs is a good proxy for the whole-plant in studying trade-offs and it could provide a convenient way to understand the whole-plant economic spectrum by focusing on the leaf economic spectrum.

Guy Sion

The present review is in part a complement to the prompt, knowledgeable and favorable review by Anderson (2016) that, however, failed to reflect certain unique aspects of the book.

Muhsin Çoğal and Mustafa Sözen

Gazella gazella was discovered recently in a restricted area in the Hatay province, Southern Turkey, which constitutes the northern most point of the distribution of this species in the world. To determine the distribution of the population of mountain gazelles in the Hatay region, 17 camera-traps were set along 45 km, on a line from the south to north along the Syrian border. The traps were in the field for about five months from late May to mid-October in 2016. Field observations and conversations with local people, wildlife officers and researchers were performed to gain more information about the habits and distribution of the gazelles. Two isolated sub-populations were found: The northern one in the Kırıkhan region; about 520 gazelles in an area of about 100 km2, and separated by 18 km to the south, and some 20 gazelles in an area of about 25 km2 in the Reyhanlı region. This southern sub-population was first discovered in this research. Fourteen species of mammals were recorded with photo-traps. Hemiechinus auritus is a new record for the Hatay region. The conservation efforts after the discovery of the northern mountain gazelle sub-population, assisted an increasing trend in its size, and resulted in finding the additional sub-population in the Reyhanlı region.