Biodiversity,exotic plant species,and herbivory: The good,the bad,and the ungulate

Invasion of natural ecosystems by exotic plant species is a major threat to biodiversity. Disturbance to native plant communities, whether natural or management induced, is a primary factor contributing to successful invasion by exotic plant species. Herbivory by both wild and domestic ungulates exerts considerable impact on structure and composition of native plant communities. Intensive herbivory by ungulates can enhance exotic plant invasion, establishment, and spread for three reasons: (1) many exotic plants are adapted to ground disturbances such as those caused by ungulate feeding, trampling, and movements; (2) many exotic plants are adapted for easy transport from one area to another by ungulates via endozoochory and epizoochory; (3) many exotic plants are not palatable or are of low palatability to ungulates, and consequently, their survival is favored as ungulates reduce or eliminate palatable, native plants. Ungulate herbivory is a chronic, landscape-scale disturbance capable of influencing plant communities as much as episodic events such as fire. Consequently, ungulate herbivory has the potential to facilitate the invasion and establishment of exotic plants in the interior Pacific Northwest where ungulates occupy nearly every ecosystem. Moreover, ungulate herbivory has intensified in many ecosystems, owing to the addition of domestic ungulates with that of existing, wild ungulates, coupled with the reduction or elimination of migratory movements and predators that previously regulated wild ungulate populations and influenced their distributions. Despite the observational evidence for ungulate herbivory as a strong facilitator of exotic plant invasion and establishment, current knowledge of cause–effect relations is severely limited by a lack of manipulative experiments. Most studies have been observational, unreplicated, and lack the experimental controls needed to eliminate or account for confounding sources of variation. Heightened attention to conservation of biodiversity will increase the importance of managing ungulates in balance with the plant communities that support them.     

Zur Weiterentwicklung eines halbsynthetischen Nährmediums fürIps typographus L.

The semiartificial diet for the bark beetleIps typographus L. ofSimsek andFührer (1993) andSimsek (1995) was further developed in its handling and composition of the vitamin solution. The biological availability of the vitamins of the vitamin b-group was investigated. The diet is useful as rearing medium for larvae, pupae and adult beetles. But it is not possible by now to grow reproducibly a whole generation cycle on this diet.     

Oceanalin B,a Hybrid α,ω-Bifunctionalized Sphingoid Tetrahydroisoquinoline β-Glycoside from the Marine Sponge Oceanapia sp.

Oceanalin B (1), an α,ω-bipolar natural product belonging to a rare family of sphingoid tetrahydoisoquinoline β-glycosides, was isolated from the EtOH extract of the lyophilized marine sponge Oceanapia sp. as the second member of the series after oceanalin A (2) from the same animal. The compounds are of particular interest due to their biogenetically unexpected structures as well as their biological activities. The structure and absolute stereochemistry of 1 as a α,ω-bifunctionalized sphingoid tetrahydroisoquinoline β-glycoside was elucidated using NMR, CD and MS spectral analysis and chemical degradation. Oceanalin B exhibited in vitro antifungal activity against Candida glabrata with a MIC of 25 μg/mL.     

Triterpene Glycosides from the Far Eastern Sea Cucumber Psolus chitonoides: Chemical Structures and Cytotoxicities of Chitonoidosides E1, F,G, and H

Four new triterpene disulfated glycosides, chitonoidosides E₁ (1), F (2), G (3), and H (4), were isolated from the Far-Eastern sea cucumber Psolus chitonoides and collected near Bering Island (Commander Islands) at depths of 100–150 m. Among them there are two hexaosides (1 and 3), differing from each other by the terminal (sixth) sugar residue, one pentaoside (4) and one tetraoside (2), characterized by a glycoside architecture of oligosaccharide chains with shortened bottom semi-chains, which is uncommon for sea cucumbers. Some additional distinctive structural features inherent in 1–4 were also found: the aglycone of a recently discovered new type, with 18(20)-ether bond and lacking a lactone in chitonoidoside G (3), glycoside 3-O-methylxylose residue in chitonoidoside E₁ (1), which is rarely detected in sea cucumbers, and sulfated by uncommon position 4 terminal 3-O-methylglucose in chitonoidosides F (2) and H (4). The hemolytic activities of compounds 1–4 and chitonoidoside E against human erythrocytes and their cytotoxic action against the human cancer cell lines, adenocarcinoma HeLa, colorectal adenocarcinoma DLD-1, and monocytes THP-1, were studied. The glycoside with hexasaccharide chains (1, 3 and chitonoidoside E) were the most active against erythrocytes. A similar tendency was observed for the cytotoxicity against adenocarcinoma HeLa cells, but the demonstrated effects were moderate. The monocyte THP-1 cell line and erythrocytes were comparably sensitive to the action of the glycosides, but the activity of chitonoidosides E and E₁ (1) significantly differed from that of 3 in relation to THP-1 cells. A tetraoside with a shortened bottom semi-chain, chitonoidoside F (2), displayed the weakest membranolytic effect in the series.     

Artificial incubation of noble crayfish (Astacus astacus) eggs in a partially recirculating system using formaldehyde as an antifungal treatment

There is little information on the long‐term artificial incubation of noble crayfish eggs. The present study evaluated artificial incubation in a partially recirculating system using formaldehyde baths as antifungal prophylaxis. Crayfish eggs were treated three times a week in a formaldehyde bath of 3000 ppm for 15 and 20 min and in 2500 ppm for 15, 20 and 25 min. In all treated groups, high final survival rates (87.8–92.0%) to stage 2 juveniles were obtained after 83 days. Significantly lower survival was observed in the control group (45.4%). It was concluded that recirculating systems can be used successfully for artificial incubation of crayfish eggs in order to conserve water. Formalin was found as an effective fungicide but its use should be carefully considered because of its safety issues for farm staff and environmental pollution.     

Mutations in target genes of succinate dehydrogenase inhibitors and demethylation inhibitors in Ramularia collo-cygni in Europe

Journal of Plant Diseases and Protection - Ramularia collo-cygni is a devastating plant pathogen of barley with an increasing importance in Europe and several other barley growing regions...     

Relationship between Norway Spruce Status and Soil Water Base Cations/Aluminum Ratios in the Czech Republic

There is a concern that soil acidification by acidic deposition, along with the resulting depletion of the labile pool of nutrient cations (e.g. Ca, Mg) and enhanced leaching of Al from soil may contribute to forest dieback. The molar ratios of Ca/Al or (Ca+Mg+K)/Al in the soil solution have been widely used as a criterion for risk of tree damage due to acidification. Intensity and quality of the crown and branch structure transformation due to formation of secondary shoots in successive series is a very sensitive indicator of long-term tree damage, and the subsequent regenerative processes. Soil water chemistry and crown structure transformation of Norway spruce were observed at 16 forest plots within the Czech Republic with the following results: parameters, expressing degradation processes in the crown (defoliation of primary structure), regeneration processes (percentage of secondary shoots) or synthetic stages of crown structure transformation showed high correlation with soil water (Ca+Mg+K)/Al ratio in organic horizons. No relationships were found for mineral horizons. The correlations between soil water and crown status parameters were considerably stronger when using the (Ca+Mg+K)/Al ratio rather than the Ca/Al ratio.     

Tree layer dynamics of the Cahnov–Soutok near-natural floodplain forest after 33 years (1973–2006)

The paper deals with the issue of the spontaneous development of Central-European floodplain forests. The research object was the Cahnov–Soutok National Nature Reserve situated on the confluence of Dyje R. and Morava R. in the Czecho–Slovak-Austrian borderland area. This locality has been left to spontaneous development since the beginning of the 1930s. In the years 1973, 1994 and 2006, the surveyed site was subjected to the measurement of standing and lying, live and dead trees reaching a diameter at breast height of 10 cm and the whole area regeneration of woody species. The work objective is to describe the most pronounced trends in tree layer changes having occurred in the period of study and to capture changes in the total tree volume and production of dendromass during the disintegration of the old grazing oak layer. The survey into the near-natural floodplain forest of Cahnov–Soutok showed that (1) the most significant trend is a decreased representation of Quercus robur in all monitored indicators and conversely an expanding representation of Acer campestre, Carpinus betulus and Tilia cordata and (2) that the floodplain forest ecosystem demonstrates a high-level stability in the total volume of tree biomass with an essential change in the tree species composition, spatial structure and average stem volume of individual trees.     

Natural development and regeneration of a Central European montane spruce forest

Montane Norway spruce forests of Central Europe have a very long tradition of use for timber production; however, recently there has been increasing concern for their role in maintaining biological diversity. This concern, coupled with recent severe windstorms that led to wide-spread bark beetle outbreaks, has brought the management of montane spruce forests to the forefront of public policy discussions in Central Europe. In order to shed light on the natural development and current structure of mature montane spruce forests, we established four 0.25 ha research plots in a semi-natural montane spruce forest in the Šumava Mountains (The Bohemian Forest), Czech Republic. We mapped all trees, extracted increment cores for age and growth-pattern analyses, and inventoried all current tree regeneration, including the substrates on which it was found. Stands were characterized by uni-modal tree diameter distributions and high basal areas (56.6 m² ha⁻¹ on average), indicating a natural transition from the stem exclusion phase towards the understory reinitiation phase. The stands showed largely single-cohort recruitment age structures, however, with recruitment spanning seven decades. Our analyses suggest that this cohort existed as advance regeneration prior to major disturbances in the late 1800s, which included post-bark beetle salvage logging. Spatial pattern analyses of living and dead stems combined, showed an increase in uniformity of living trees, pointing to the role of natural density-dependent mortality. However, past growth patterns and historical documentation suggest that low intensity canopy disturbances (wind and snow) also caused mortality and diversified canopy structure. Because the stands developed naturally over the past 120+ years and thus escaped thinning operations, high volumes of coarse woody debris (94 m³ ha⁻¹) and snag densities (546 stems ha⁻¹) have accrued. Advance spruce regeneration was quite abundant and existed primarily on deadwood substrates, even though these occupied only a small percent of stand area. Because of salvage logging in the late 1880s, these stands do not qualify, according to the traditional paradigm, as natural spruce forests. As a result, they are recently subject to active management practices including salvage logging that remove dead and dying trees. Given the importance of deadwood for forest regeneration and recovery from disturbance, as demonstrated in this study, we argue that dead wood removal may limit future natural regeneration in these stands. Thus, the purported benefits of removing dead and dying trees from semi-natural forests must be carefully weighed against the potential detrimental impacts on natural spruce forest regeneration and biodiversity.     

Effects of supplementary feeding in carp ponds on discharge water quality: a review

Discharge of aquacultural wastewater can lead to eutrophication and disruption of natural ecosystems in receiving water bodies. A controlled waste production strategy is necessary, therefore, in order to maintain sustainable aquacultural growth. Along with fertilisation, supplementary feeding is the major source of allochthonous matter in aquaculture and management of aquacultural waste, therefore, should be approached through diet formulation and/or feeding strategy. The introduction of highly digestible feed has reduced solid waste excretion, and further reductions can be achieved through careful selection of ingredients and processing to improve nutrient availability. Dissolved nitrogen waste can be reduced by ensuring a balance between protein and energy, such that fish use non-protein sources as energy, while phosphorous waste can be reduced through careful ingredient selection and processing to improve digestibility. Thermal and mechanical treatment of feed cereals prior to application can also help decrease the amount of poorly or undigested feed. Finally, feeding practices that minimise wastage should also be explored as they have a significant impact, not only on waste output but also on the overall economy of carp pond farming.