CO2 enrichment of sour orange trees: 2.5 years into a long-term experiment

Abstract. Eight sour orange trees have been grown from seedling stage in the field at Phoenix, Arizona, U.S.A., in four identically-vented, open-top, clear-plastic-wall chambers for close to 2.5 years. Half of the chambers have been maintained at ambient atmospheric CO2 concentrations over this period, while half of them have been maintained at 300 ppm (300 μlmol CO₂ per mol air) above ambient. Initially, the trees in each treatment were essentially identical; but in less than 2 years, the trunks of the CO₂-enriched trees had become twice as large as their ambient-treatment counterparts. After 2 full years of growth, the enriched trees had 79% more leaves, 56% more primary branches with 172% more volume, 70% more secondary branches with 190% more volume, and 240% more tertiary branches with 855% more volume. In addition, the CO2-enriched trees also had fourth-, fifth- and sixth-order branches, while the ambient-treatment trees had no branches above third order. Total trunk plus branch volume of the CO₂-en-riched trees was 2.79 times that of the ambient-treatment trees after 2 fulf years of growth.     

Hierarchical Bayesian model reveals the distributional shifts of Arctic marine mammals

Aim

Our aim involved developing a method to analyse spatiotemporal distributions of Arctic marine mammals (AMMs) using heterogeneous open source data, such as scientific papers and open repositories. Another aim was to quantitatively estimate the effects of environmental covariates on AMMs’ distributions and to analyse whether their distributions have shifted along with environmental changes.

Location

Arctic shelf area. The Kara Sea.

Methods

Our literature search focused on survey data regarding polar bears (Ursus maritimus), Atlantic walruses (Odobenus rosmarus rosmarus) and ringed seals (Phoca hispida). We mapped the data on a grid and built a hierarchical Poisson point process model to analyse species’ densities. The heterogeneous data lacked information on survey intensity and we could model only the relative density of each species. We explained relative densities with environmental covariates and random effects reflecting excess spatiotemporal variation and the unknown, varying sampling effort. The relative density of polar bears was explained also by the relative density of seals.

Results

The most important covariates explaining AMMs’ relative densities were ice concentration and distance to the coast, and regarding polar bears, also the relative density of seals. The results suggest that due to the decrease in the average ice concentration, the relative densities of polar bears and walruses slightly decreased or stayed constant during the 17‐year‐long study period, whereas seals shifted their distribution from the Eastern to the Western Kara Sea.

Main conclusions

Point process modelling is a robust methodology to estimate distributions from heterogeneous observations, providing spatially explicit information about ecosystems and thus serves advances for conservation efforts in the Arctic. In a simple trophic system, a distribution model of a top predator benefits from utilizing prey species’ distributions compared to a solely environmental model. The decreasing ice cover seems to have led to changes in AMMs’ distributions in the marginal Arctic region.     

Can aerial herbicide application control Grey Willow (Salix cinerea L.) and stimulate native plant recovery in New Zealand wetlands?

Grey Willow (Salix cinerea L.) poses a significant threat to wetland ecosystems in New Zealand. To manage the ecological impacts and to control further spread, cost‐effective large‐scale control methods are needed. We investigated the response of Grey Willow and dominant wetland plant groups to the aerial boom‐spray application of glyphosate at 9 L/ha and triclopyr (amine) at 18 L/ha at three New Zealand wetlands. We found glyphosate substantially reduced the dominance of tall (>2 m) Grey Willow with commensurate increases in the dominance of most native plant groups. Triclopyr (amine) application resulted in poor Grey Willow control, was not associated with increased native plant group dominance, and some native plant groups declined where triclopyr (amine) was applied. We conclude that the aerial application of glyphosate is an effective large‐scale Grey Willow control tool and could be used to initiate the restoration of native plant communities in wetlands dominated by Grey Willow. But, evidence of Grey Willow recovery after control suggests that increases in native plant dominance will be reversed as Grey Willow re‐establish. Further research is needed to determine how to maintain and enhance native plant dominance after control, and to determine how to manage Grey Willow in fen areas where the Grey Willow canopy is discontinuous and nontarget herbicide impacts can occur. The aerial boom‐spray application of triclopyr (amine) for large‐scale Grey Willow control should be discontinued as it does not provide effective control and results in negative ecological outcomes.     

Eupatarone,A 2-acetylbenzofuran from Eupatorium sternbergianum

A new benzofuran, eupatarone, together with 2-hydroxy-4, 5-dimethoxybenzaldehyde, 12-hydroxy-2, 3-dihydroeuparine, spathulenol, precocene II, dammaradienol, dammaradienol acetate, 5, 3′-dihydroxy-7, 4′-dimethoxyflavanone and 5, 7-dihydroxy-4′-methoxyflavanone, have been isolated from aerial parts of Eupatorium sternbergianum.     

Two further acylated flavone glucosides from Anisomeles ovata

The structures of two new acylated apigenin glucosides are reported from the aerial parts of Anisomeles ovata. They were separated as their acetates and identified as apigenin 7-O-β-d-(2″,6″-di-O-p-coumaroyl)glucoside and apigenin 7-O-β-d-(4″,6′-di-O-p-coumaroyl)glucoside by ¹H NMR study of the acetates and by chemical degradative methods. The allocation of the p-coumaroyl moieties is also supported by a study of the ¹³C NMR spectrum of the inseparable mixture of glucosides.     

Plant-Parasitic Nematodes of South Viet Nam

Between 1974 and 1978, 2,842 identifications of plant-parasitic nematodes were made from more than 1,700 soil and plant samples collected in eight provinces of South Viet Nam. Species in nine genera—Helicotylenchus, Criconemoides, Meloidogyne, Pratylenchus, Tylenchorhynchus, Hoplolaimus, Hirschmanniella, Xiphinema, and Rotylenchulus—comprised 96.1% of the identifications; the remaining 3.9% were species of 11 genera. Fourteen genera were associated with rice which was grown on about 2,500,000 ha in 1970. Of these, Ditylenchus, Hirschmanniella, and Meloidogyne were most important. Ditylenchus angustus caused severe damage to about 50,000 ha of flooded rice in the Mekong Delta in 1976. Hirschmanniella spp. were found in all samples examined from flooded rice fields. Meloidogyne spp. were common in rice seedbeds, upland rice, and rice not kept flooded continuously. Meloidogyne and Pratylenchus spp. were found in roots of 22 of the 32 crop plants sampled. Little or no attempt was made in South Viet Nam to control nematodes.     

Stomatal types ofCactaceae

The stomatal types (i.e. the arrangement of epidermal cells in the vicinity of a stomatal pore in superficial view) have been examined in more than 150 taxa ofCactaceae, mostly using documented material. Preparations have been made by mazerating pieces of tissue with modified Jeffrey's Solution and staining with chlore-zinc-jodine.—The examined members of the subfamilyCactoideae showed parallelocytic stomata with only minor deviations in a number of cases. Members of the subfamiliesPereskioideae andOpuntioideae show parallelocytic stomata on the leaves, but the stomatas of the stem represent a different type, which apparently is not yet described. It is termed opuntioid here. In most cases the stomata are superficial but a few taxa show markedly sunken or hidden stomata.—In taxa of the subfamiliesPereskioideae andOpuntioideae the stomata are generally oriented parallel to the stem axis with only minor deviations. The stomata of taxa of the subfamilyCactoideae do in general not show a particular orientation with the notable exception of a number of epiphytic genera from the tribeHylocereeae.—The results of these investigations in general coincide well with the generic classification of theCactaceae byHunt (1967). A few cases where stomatal characters suggest a differing classification merit further investigations.—Additionally, the possibilities to distinguish between paracytic and parallelocytic stomata are discussed and an amended definition for the latter is given.     

Herpetological research in zoos: A literature survey, 1977–1981

Herpetological zoo research published in three journals between 1977 and 1981 was surveyed. Fifty-three of 1,084 published papers involved zoos. Research for 30 papers was conducted in zoos. Just under three fourths of zoo papers involved behavioral research. Sixteen zoos were involved in research in this survey.     

European Vegetation Survey: update on progress

Abstract. Progress in the European Vegetation Survey is described. 25 countries are now represented in a network committed to common data standards in phytosociological survey, the development of compatible software for data analysis and mapping, the encouragement of national programmes and the development of an overview of European plant communities. Advances in each of these areas of activity is summarised and plans for the future are outlined, most notably the production of a book ‘The Vegetation of Europe’.     

Immunochemical comparisons of ribulosebisphosphate carboxylases using antisera to tobacco and spinach enzymes

Ribulosebisphosphate carboxylase molecules from over 50 species of angiosperms and gymnosperms have been compared by quantitative microcomplement fixation, using antisera prepared against tobacco and spinach enzymes. There were close antigenic similarities between tobacco enzyme, enzymes from other members of the Solanaceae, and enzymes from members of the Nolanaceae, Cuscutaceae, and Convolvulaceae. There were relatively close similarities between spinach enzyme and enzymes from two other members of the Chenopodiaceae. There were relatively great differences between tobacco enzyme, spinach enzyme, and most other enzymes tested. The enzymes from most of the angiosperms tested were as different from tobacco enzyme and almost as different from spinach enzyme as were the enzymes from the gymnosperms.