In the arid region of northwest China, H. ammodendron has become the main pioneer species for the restoration of plant communities. However, the breeding system of the plant remains unknown. The floral dynamics and the breeding system characteristics of H. ammodendron were investigated in this study, using a bagging experiment. The results show that anthesis lasted about 22 d. The longevity of individual flowers was 14.1 d. Stigma receptivity lasted about 6 d and there were relatively long periods for the meeting between stamen and stigma. Anther height was slightly greater than that of the stigma. The outcrossing index was 2 and the pollen-ovule ratio was 64,815. The H. ammodendron mating system can be described as a mixed mating system with facultative apomixis; pollination is not necessary for reproduction. The mixed mating system with facultative apomixis could guarantee the reproductive success of H. ammodendron in severe desert conditions with sparse pollinators.
Justin R. St. Juliana, Burt P. Kotler, Berry Pinshow and Noga Kronfeld-Schor
We studied the influence of manipulating predation risk on Allenby’s gerbil ( Gerbillus andersoni allenbyi) held in a large, outdoor enclosure. We measured giving up densities (GUDs), apprehension, time allocation to foraging, harvest strategy (grab and go (GAG) vs. eat at tray (EAT)), and fecal cortisol concentration. First we established the time necessary for cortisol and corticosterone concentrations to change significantly from baseline after a stressful experience. To do this we collected feces from gerbils 2, 4, 6, or 8 hours after being handled (treatment) or not (control). After 8 h, fecal cortisol, but not corticosterone, concentration was significantly higher in treatment animals. We used the results from the hormone time course experiment to design the predation experiment. We used a dog, trained to harass gerbils, to increase predation risk for the gerbils. We predicted that fecal cortisol concentrations would increase directly in the face of predation risk, or indirectly, due to reduced foraging time because of perceived predation risk that, in turn, leads to increased hunger levels. As predicted, in the presence of a predator, GUDs were higher, time allocation lower, and GAG foraging was used more in treatment animals than in controls, but we found no change in apprehension. There was no difference in cortisol concentration between predator present and no-predator treatments. However, individuals that tended to have higher average fecal cortisol concentrations also tended, on average, to spend more time foraging. This indicates a relationship between stress hormones and optimal foraging. This relationship is potentially causal. While nightly changes in behavior may not be related to stress hormones, over course time scales, stress hormones may be driving gerbils to forage more.
Justin R. St. Juliana, Jocelyn L. Bryant, Nadja Wielebnowski and Burt P. Kotler
We evaluated the suitability of a corticosterone enzyme immunoassay (EIA) to monitor excretion of fecal glucocorticoid metabolites (FGM) in response to Adrenocorticotropic hormone (ACTH) and saline injections in three desert rodent species (Gerbillus andersoni allenbyi (GA), Gerbillus nanus (GN), and Gerbilis piridium (GP). We exposed 24 gerbils (N = 9 for GA, N = 7 for GN, N = 8 for GP) to an ACTH and a saline injection at different times. Fecal samples were collected hourly for 24 hours after injection. The average starting concentration (baseline) FGM concentration was 797 ng/g for GA, 183 ng/g for GN, and 749 ng/g for GP. The average peak concentration was 2377 ng/g for GA, 589 ng/g for GN, and 1987 ng/g for GP. We were able to provide a physiological validation for the chosen assay in GAs and GPs, however, our results for GNs were less clear. We found an increase in FGM concentrations on average after 5.5 hours in GA, 3.1 hours in GN, and 3.8 hours in GP. We found a peak in FGM concentration on average after 8.8 hours in GA, 5.6 hours in GN, and 10.3 hours in GP. We determined that FGM concentration returned to starting value on average after 14.4 hours in GA, 9.1 hours in GN, and 15.1 hours in GP. The outcomes of this study can help establish trapping protocols and time frames for FGM monitoring of these wild small mammal populations. The time course for excretion of FGM is similar between the species in this study, and comparable to some non-desert rodents. We found high variation in the time course of excretion within species. This variation needs to be taken into account when monitoring stress responses in the field. By assessing adrenocortical activity using FGM monitoring, stress responses to varying ecological and environmental factors can be reliably examined in the field.
Rachel Schwarz, Gavin Stark and Shai Meiri
The south-facing slopes in canyons, oriented along an east-west axis north of the equator, are often hotter and drier than north-facing slopes, promoting differences in the biotic and abiotic characteristics of the opposing slopes. We studied how diversity and abundance patterns have changed in Oren stream (Carmel Mountains, Israel) during the last 25 years. We tested whether temperature and habitat preferences of reptiles affected observation frequencies, to assess potential effects of global warming on the reptiles. We compared the results of a 1993–1994 survey in Oren stream to a survey we conducted during 2017–2018, using similar methods, survey area and effort. Species composition and abundance in Oren stream did not significantly change between studies, but the proportion of observations differed significantly across slopes for four out of the six most abundant species. The number of observations increased monotonically with increasing temperatures on the south-facing slope, but decreased on the north-facing slope above a temperature of 22°C. The major biome species inhabit globally was unrelated to the number of observations across slopes or studies, but species inhabiting warmer ranges were more frequently observed in the current survey. Our results suggest that as global temperatures rise, reptile species which can tolerate higher temperatures, and those which can avoid the hottest temperatures of the day, may be able to cope better. These results however may also derive from better detection ability of some species over others between study teams.
Aitzhamal S. Mussina, Gaukhar U. Baitasheva, Meruyert S. Kurmanbayeva, Galia J. Medeuova, Adilhan A. Mauy, Elmira M. Imanova, Akbota Zh. Kurasbaeva, Zaida S. Rachimova, Yerlan S. Nurkeyev and Kanat Orazbayev
Reaction of the plant body in polluted conditions allows estimating the anthropogenic impact on the environment. The aim of this work is to study anatomical and morphological changes of juniper in terms of the polymetallic pollution of the environment and under the influence of heavy metals. The assessment of some heavy metals impact on juniper was conducted after the planting of seed samples in the soil and obtaining good germination. The juniper has been treated with heavy metal solutions in the lab for 4 months. To determine the anatomical structures of the leaves of the juniper, the samples were fixed by the Strasburger-Fleming method. Under the influence of urban air, negative anatomical and morphological changes of juniper were discovered, the significant increase in the thickness of the needles, the thickness of the conducting bundle and the thickness of the epidermis was noted, that, apparently, provides higher resistance to man-induced pollution. It is shown that the process of environmental restoration can be done due to self-purification by using adsorption properties of leaves of woody plants, for example juniper, that is able to absorb heavy metals (lead, cadmium, cobalt, chromium, nickel, zinc and copper) from urban air. It was first discovered that the effects of heavy metals (lead and nickel) as the nutrient medium leads to the significant changes of the leaves’ anatomical structure (the swelling of the phloem, some decondensation in the mesophyll). The research results allow recommending the juniper for phytoremediation, bioindication and landscape gardening of cities and settlements in different countries.
Zulkiya Namazbaeva, Sharbanu Battakova, Lyazat Ibrayeva and Zhanbol Sabirov
Risk factors in Aral Sea region include toxic metals that competitively interact with essential elements influencing their metabolism, affecting metabolic and cognitive functions. According to epidemiological data, cerebrovascular disease and thyroid function abnormality are the leading disorders. Cognitive and metabolic disorders are considered as risk factors in cerebrovascular diseases. Thus, the objective of current work was to determine the metabolic and cognitive state of people in Aralsk, associated with an imbalance of essential trace elements and find correlation between toxic metals load and psychoemotional status. 275 people between the ages of 21 and 45 years were involved. In evaluating cognitive state, a decrease in short-term memory for numbers and an increase in depression among subjects was found. An inverse correlation between the copper level in blood and short-term memory for numbers, between depression and iodine level in blood, between the zinc level in blood and the “attentional capacity” was also found. The results showed a significant metabolic stress among subjects during adaptation to a high chemical load. Data represent a cross-sectional age-dependent review of metabolic and cognitive processes and microelement metabolism among population, living in the Aral Sea region for a long time.
Yong-hua Zhu, Sheng Zhang, Biao Sun, Xiao-kang Xi, Yu Liu and Xiao-hong Shi
Quantification of the pattern and spatial distribution of soil organic carbon (SOC) is essential to comprehending many eco-hydrological processes. To obtain a better understanding of the spatial variability of SOC in a typical farming-pastoral zone, 270 soil samples were collected at 45 sampling sites from every 20 cm soil layer. Semi-variance function theory and ordinary Kriging interpolation were applied to identify the spatial variability of SOC. The results showed that SOC in the area was relatively low and decreased with depth and from the basin edge to the centre with a measured mean content of 0.07–0.65 g/kg. The strongest variability in the zone in the top soil layer (0–40 cm) was in the centre part of the zone, which was supposed to be the most concentrated area of human activities in the zone. As soil depth increase, the degree of variation of SOC decreased. Gaussian, exponential, and spherical models were suggested to successfully simulate SOC in different soil depth zones. The spatial distribution of SOC showed strong variability in the same soil depth zone, with a nugget to sill ratio of less than 14% and a range of 30–160 km.
Jong Myong Park, Ji Won Hong, Jin-Soo Son, Ye-Ji Hwang, Hyun-Min Cho, Young-Hyun You and Sa-Youl Ghim
This review focuses on the state of research on the microbial resources of Dokdo, Korea, as a strategy for securing national microbial resources. In the Korean peninsula, studies aimed at securing microbial resources are carried out across diverse natural environments, especially in the Dokdo islands. Until 2017, a total of 61 novel microbial genera, species, or newly recorded strains have been reported. Among these, 10 new taxa have had their whole genome sequenced and published, in order to find novel useful genes. Additionally, there have been multiple reports of bacteria with novel characteristics, including promoting plant growth or inducing systemic resistance in plants, calcite-forming ability, electrical activation, and production of novel enzymes. Furthermore, fundamental studies on microbial communities help to secure and define microbial resources in the Dokdo islands. This study will propose several tactics, based on ecological principles, for securing more microbial resources to cope with the current increase in international competition for biological resources.
Corrado Battisti and Francesca Marini
We report data on the effects of coppice management on breeding birds in paired oak woods of central Italy using a Before-After-Control-Impact sampling design, hypothesizing that this practice strongly affect abundance, richness and diversity at community level. Using point count method, we obtained first evidence of a coppice management effect acting as a stressor on the breeding bird assemblage structure. We observed a significant decrease in averaged species richness and abundance in coppiced areas before and after the coppicing practices, differently from the control area. Analogously, regression lines derived by species frequencies in diversity/dominance diagrams showed a different trends when comparing the coppiced areas before and after the cutting, indicating a stress in the latter. This pattern is supported by the H’ diversity and evenness values that changed abruptly between years only in the coppiced area. These changes can be related to the significant reduction in tree plant density before and after cutting, especially for those with a diameter between 7.5 and 23 cm.