The colonization of decaying logs by vascular plants and the consequences of fallen logs for herb layer diversity in a lowland alluvial forest

The presence of coarse woody debris in forests is an important naturalness criterion as well as a biodiversity indicator. Decaying logs provide habitat for many organisms including vascular plants. The aims of this study are to describe the colonization of decaying logs by vascular plants in a lowland alluvial forest and to assess the impact of fallen logs on the biodiversity of the herb layer. We investigated 493 logs in the Ranšpurk National Nature Reserve in southern Moravia. For each log, we recorded species of vascular plants rooting on its surface. Decaying logs were characterized by their dimensions, woody species and decay class. Vascular plants rooted on 279 surveyed logs. Decaying logs were colonized by 79 species of vascular plants. Terrain relief was found to be a significant factor for colonizing species. Our study did not find any significant spatial pattern of colonized logs with regard to the distribution of vascular plants, intensity of colonization or the ecological demands of colonizers. The colonization of lying logs by vascular plants was significantly influenced by the species of logs, their surface area and decay class. Species composition of vascular plants on decaying logs and that on mineral soil were significantly different. Demonstrably higher frequencies of Dryopteris carthusiana and Impatiens parviflora were found on decaying logs. The presence of decaying logs and the microsites they create is important for total forest biodiversity including the diversity of vascular plants. We recommend increasing the proportion of decaying logs even in commercial forests.

     

Selective inhibition of a regulatory subunit of protein phosphatase 1 restores proteostasis

Many biological processes are regulated through the selective dephosphorylation of proteins. Protein serine-threonine phosphatases are assembled from catalytic subunits bound to diverse regulatory subunits that provide substrate specificity and subcellular localization. We describe a small molecule, guanabenz, that bound to a regulatory subunit of protein phosphatase 1, PPP1R15A/GADD34, selectively disrupting the stress-induced dephosphorylation of the α subunit of translation initiation factor 2 (eIF2α). Without affecting the related PPP1R15B-phosphatase complex and constitutive protein synthesis, guanabenz prolonged eIF2α phosphorylation in human stressed cells, adjusting the protein production rates to levels manageable by available chaperones. This favored protein folding and thereby rescued cells from protein misfolding stress. Thus, regulatory subunits of phosphatases are drug targets, a property used here to restore proteostasis in stressed cells.     

Pineal vasotocin: release into cat cerebrospinal fluid by melanocyte-stimulating hormone release-inhibiting factor

The intracarotid injection of both synthetic melanocyte-stimulating hormone release-inhibiting factor (MIF) and purified MIF prepared from bovine hypothalami induces arginine vasotocin release into cerebrospinal fluid of cats and significantly decreases the pineal arginine vasotocin content at 5 minutes after the injection. The present results demonstrate an extrapituitary endocrine effect of synthetic and purified bovine MIF.     

Complex patterning by vertical interchange atom manipulation using atomic force microscopy

The ability to incorporate individual atoms in a surface following predetermined arrangements may bring future atom-based technological enterprises closer to reality. Here, we report the assembling of complex atomic patterns at room temperature by the vertical interchange of atoms between the tip apex of an atomic force microscope and a semiconductor surface. At variance with previous methods, these manipulations were produced by exploring the repulsive part of the short-range chemical interaction between the closest tip-surface atoms. By using first-principles calculations, we clarified the basic mechanisms behind the vertical interchange of atoms, characterizing the key atomistic processes involved and estimating the magnitude of the energy barriers between the relevant atomic configurations that leads to these manipulations.     

The influence of crate height on selected biochemical indices in captive‐reared mallards

The aim of this study was to investigate the effects of crate type (particularly its height) on selected biochemical indices in captive‐reared mallards (Anas platyrhynchos). The physiological changes in response to 2‐h crating in crates of either 20 cm or 26 cm height were monitored in 6‐week‐old mallards. Plasma corticosterone concentrations showed an increase (P = 0.036) in mallards crated in crates of 26 cm height in comparison with control non‐crated birds, whereas no difference in plasma corticosterone levels was found between mallards crated in crates of 20 cm height and control non‐crated birds. Lower concentrations of plasma triglycerides (P < 0.05) and uric acid (P < 0.05) were found in crated mallards in comparison with control non‐crated birds; the height of the crates had no effect. Mallards crated in crates of 26 cm height also exhibited a higher (P = 0.032) plasma lactate dehydrogenase concentration in comparison with control non‐crated birds, whereas no difference (P > 0.05) was found in lactate dehydrogenase concentrations in mallards crated in crates of 20 cm height. Our results suggest that crating mallards in lower crates (20 cm) may be less stressful than keeping them in crates allowing vertical movements of the birds.     

Impacts of otter (Lutra lutra L.) predation on fishponds: A study of fish remains at ponds in the Czech Republic

The increasing numbers of otters (Lutralutra L.), which are protected by the CzechAct of Nature and Landscape Protection, arecausing serious problems for fishpondmanagement. The diet of otters on pond farmsconsists predominantly (80%) of common carp,Cyprinus carpio, and to a lesser extentother pond fish species (perch, Percafluviatilis, zander, Stizostedionlucioperca and grass carp, Ctenopharyngodon idella). The size of carpcaptured by otters ranged between 376–683 mmTL (500 ± 88 mm) and 1,049–11,768 g(3,478 ± 2,867 g). Reconstructed originalweight and length of captured grass carp andperch were 599 and 182 mm TL, and 2,665 and163 g, respectively. In most of prey fishcorpses left by otters, only viscera andassociated parts were consumed. The weight ofindividual common carp corpses was estimated as73.0 ± 24.6 (26.3–95.9)% of theoriginal reconstructed weight, which means thatonly 27.0 ± 17.2 (4.1–73.7)% of fishbody mass was consumed by otters. In perch,62.8% of fish body mass was left unconsumed.Heavy losses have been reported also on fishstocks in ice-covered ponds during the winterperiod, when shoals of resting fish have beendisturbed and stressed due to otter hunting.     

Tree spatial patterns of Abies alba and Fagus sylvatica in the Western Carpathians over 30 years

The decline of Abies alba (fir) in natural fir–beech forests in Europe has fascinated scientists for over a century. During this period, Fagus sylvatica (beech) became the dominant species in this forest type. We hypothesised that (1) the success of beech over fir is significantly connected with the fact that beech suffers less than fir from the presence of conspecific neighbours; that (2) shade tolerance is not a factor which favours beech over fir; and that (3) this is due to a significantly reduced proportion of litter treethrow mounds with suitable conditions for the successful regeneration of fir. We investigated these hypotheses by means of tree spatial pattern analysis. Eight rectangular plots (2–8 ha) were analysed in mountain fir–beech forests of the Outer Western Carpathians, Czech Republic. Various types of the pair correlation function and L function were used to describe the tree density variability of trees with DBH ≥10 cm. The analyses were carried out on datasets from the 1970s, 1990s and 2000s. Our results suggest that negative density dependence is not responsible for the current decline of fir. It seems that a higher shade tolerance of the advanced regeneration could be one of the factors which favour beech over fir. It is evident that fir trees have a markedly stronger positive association to mounds than beech trees.     

Acidification of primeval forests in the Ukraine Carpathians: Vegetation and soil changes over six decades

Changes to vegetation and soil were assessed in primeval forests of the Eastern Carpathians after a period of 59-68 years. We hypothesized that forest ecosystems were acidified through the long-distance transport of air pollutants. A total of 141 relevés and 20 soil profiles that had been studied in 1938 in spruce- and beech-dominated forests along an altitudinal gradient ranging from 1085-1575 m a.s.l. were re-surveyed from 1997 to 2006. Relevés were analyzed using multidimensional statistics and plant community characteristics (Shannon-Wiener’s index, equitability, fidelity, Ellenberg indication values - EIV); soil reaction and sorption complex properties were analyzed in soils.A total of 159 vascular plant taxa were recorded in 1938, of which 35 were not found during the repeat survey. During the later survey, 137 taxa were found, of which 13 were new findings. The upper mineral (A) as well as cambic or spodic (B) horizons were considerably acidified in both forest types. Both active and exchange soil reaction decreased by 0.1-0.3 units on average, exchangeable acidity significantly increased and the sum of base cations decreased in both soil horizons and forest types. Base saturation decreased by more than half of original values, with a maximum decrease of 68% found in the B-horizon of spruce forests. Whereas the herb layer developed along with soils in beech-dominated forests, EIV values for soil reaction increased in spruce-dominated forests, probably due to the movement of broadleaf woody species to higher elevations or due to the higher resistance of herb species to soil acidification. Significant changes to EIVs also occurred in the beech- and/or spruce-dominated forests for the factors of nitrogen, light moisture and temperature.There was an expansion of the lower tree and shrub layers, primarily Fagus sylvatica, Picea abies and Sorbus aucuparia in intermediate and higher elevations, which can be explained by reduced cattle grazing. Also, the dissipation of Juniperus communis and marked decline of Abiesalba are interpreted as being related to gradual changes in landscape management along with the effect of acid deposition. Since 1938, all stands have shown a significant increase in nitrophilous taxa such as Rubusidaeus, Athyrium distentifolium, Urtica dioica, Calamagrostis arundinacea, Stellaria nemorum. Significant decreases in the number of species, Shannon-Wiener’s index and equitability were only observed in spruce-dominated forests. Neophyte taxa were not detected in either the 1930s or the 1997-2006 period.