Lichens and bryophytes as indicators of old‐growth features in Mediterranean forests

Abstract

This study is focused on the selection of variables affecting lichen and bryophyte diversity in Mediterranean deciduous forests. Plots representing two forest types (Fagus sylvatica and Quercus cerris forests) and two forest continuity categories (old‐growth (OG) and non‐OG forests) were selected in the Cilento and Vallo di Diano National Park (Italy). The presence and the abundance of bryophytes and epiphytic lichens were recorded. Structural variables of the forests and vascular plant species richness have been used as predictors. A strong positive correspondence between the two groups of organisms was found. Higher species richness and the distribution of rare species are related to OG stands, while a qualitative (species composition) rather than a quantitative (species richness) difference between the two forest types was observed. Some species elsewhere considered as indicators of forest continuity, such as Lobaria pulmonaria, Antitrichia curtipendula, and Homalothecium sericeum, are associated with OG forests, independently from forest type, suggesting that they can be regarded as suitable indicators also in Mediterranean forests. Finally, our results suggest that old trees, high levels of basal area, a broad range of diameter classes, and high understory diversity are the main structural features affecting cryptogamic communities, while no correlation was found with the occurrence of deadwood.     

Estimating and comparing food availability for tree‐seed predators in typical pulsed‐resource systems: Alpine conifer forests

Abstract

Alpine conifers produce pulsed resources for the community of tree‐seed consumers. Here, we describe field and statistical methods to estimate spatio‐temporal variation in seed‐crops in forests with different species composition. Annual and between‐site variation in seed production was high and characterised by occurrence of mast‐crops followed by seed‐crop failure the following year. Seed‐crops of different species did not fluctuate in parallel.

Abbreviations: DLSM, differences of least square means; CED, Cedrasco; OGA, Oga; VAL, Valfurva; BOR, Bormio; RHE, Rhemes; COG, Cogne     

Diversity of saproxylic bryophytes in old‐growth and managed beech forests in the central Balkans

Abstract

The diversity of saproxylic bryophyte species in beech forest stands from the wide region of the central Balkans (i.e. Serbia and Montenegro) was studied, and this study is the first of such a type in SE Europe. Comparison of preserved old‐growth and managed forests were made. Bryophyte species diversity is higher in primeval forest stands where the spectra of dead wood in various decaying stages of its dynamics are present. The ecological group of epixylic specialists is predominant among the bryophytes recorded. Threatened bryophyte species occur in old‐growth beech stands. The dead wood as habitat together with some other factors are extremely important for the surviving of epixylic bryophyte; so these species can be used as bioindicator bryophyte species of old‐growth or managed and structured forest ecosystems.     

Linking taxonomical and functional biodiversity of saproxylic fungi and beetles in broad‐leaved forests in southern Italy with varying management histories

Abstract

The fundamental ecological significance of deadwood decomposition in forests has been highlighted in several reviews, some conclusions regarding silviculture being drawn. Old‐growth forests are natural centres of biodiversity. Saproxylic fungi and beetles, which are vital components of these ecosystems, occupy a variety of spatial and trophic niches. Fungal and beetle diversity on coarse woody debris (CWD) was analysed in 36 forest sites in the Cilento and Vallo di Diano National Park, Italy. The data were analysed by DCA and Spearman’s rank correlation. The results provide empirical evidence of the existence of a pattern of joint colonization of the woody substrate by fungi and beetles, which includes an assemblage of reciprocal trophic roles within fungal/beetle communities. These organisms act together to form a dynamic taxonomical and functional ecosystem component within the complex set of processes involved in wood decay. The variables most predictive of correlations between management‐related structural attributes and fungal/beetle species richness and their trophic roles for old‐growth forest are: number of logs, number of decay classes and CWD total volume. Deadwood spatio‐temporal continuity should be the main objective of forest planning to stop the loss of saproxylic fungal and insect biodiversity.     

Synthesis and Biological Evaluation of Novel Apio Nucleosides with Thiazole‐4‐carboxamide and 1,2,4‐Triazole‐3‐carboxamide

In view of biological activities of azole nucleosides and apio‐dideoxynucleoside, novel apio nucleoside analogues (1 and 2) with thiazole and triazole base moiety were synthesized using 2,3‐O‐isopropylidene‐apio‐β‐d‐furanose (3), which was prepared from d‐mannose.     

Intra‐ethnic and inter‐ethnic marriage and divorce in Hawaii

Abstract

A comparison of intra‐ and inter‐ethnic divorce rates in Hawaii showed that inter‐ethnic marriages resulted in a higher proportion of divorces than did intra‐ethnic marriages when the marriage data used had to do with all marriages occurring in Hawaii. However, a sizeable portion of marriages in Hawaii are of nonresidents who, if they divorce, probably divorce elsewhere. Nonresident marriages are chiefly intra‐ethnic marriages of Caucasians. When examining the proportions of divorces to resident marriages, within‐group marriages are more at risk than inter‐ethnic marriages. As in prior research, persons who marry members of other racial/ethnic groups tend to marry persons from groups with income levels similar to their own. As in previous reports, some cross‐ethnic combinations appeared more at risk for divorce than did others. Group income appeared to be a predictor of risk. When considering only resident marriages as related to divorces, those marriages in which the bride was from a higher income group than the groom were at a significantly greater risk for divorce than marriage in which the bride came from an income group lower than that of the groom.     

Synthesis and Antiviral Properties of Arabino and Ribonucleosides of 1,3‐Dideazaadenine, 4‐Nitro‐1, 3‐dideazaadenine and Diketopiperazine

Different arabinosides and ribosides, viz. Ara‐DDA or 9(1‐β‐d‐arabinofuranosyl) 1,3‐dideazaadenine (6), Ara‐NDDP or 9(1‐β‐d‐arabinofuranosyl) 4‐nitro‐1,3‐dideazapurine (7), Ara‐DKP or 1(1‐β‐d‐arabinofuranosyl) diketopiperazine (8), Ribo‐DDA or 9(1‐β‐d‐ribofuranosyl) 1,3‐dideazaadenine (9) and Ribo‐NDDP or 9(1‐β‐d‐ribofuranosyl) 4‐nitro‐1,3‐dideazapurine (10) have been synthesized as probable antiviral agents. The arabinosides have been synthesized using the catalyst TDA‐1 that causes stereospecific formation of β‐nucleosides while a one‐pot synthesis procedure was adopted for the synthesis of the ribonucleosides where β‐anomers were obtained in higher yields. All the five nucleoside analogs have been screened for antiviral property against HIV‐1 (III_B), HSV‐1 and 2, parainfluenza‐3, reovirus‐1 and many others. It was observed that arabinosides had greater inhibitory action than ribosides. The compound 7 or Ara‐NDDP has shown maximum inhibition of HIV‐1 replication than the rest of the molecules with an IC₅₀ of 79.4 µg/mL.     

Development policy,forests, and peasant farms: Reflections on Huastec-managed forests’ contributions to commercial production and resource conservation

The Huastec Indians of northeastern Mexico manage their forests in an indigenous system that integrates commercial and subsistence production. Elements of primary and secondary forest coexist with introduced species in this diverse silvicultural structure which complements the swidden and permanent agriculture fields of the Huastec farmstead. The forest’s direct production of the food, timber, and fuel resources discussed here buffers the Huastec peasant family against market fluctuations and the failed harvest of a single crop. The Huastec system of forest management offers an alternative pattern to the agroforestry and plantation schemes now being suggested for development in the tropics. It is an alternative that provides protection for wild genetic resources while it contributes to the combination of commercial and subsistence agriculture so important for the successful modernization of peasant agriculture. The documentation of this system demonstrates that ethnobotanists and economic botanists have an important but unrealized role to play in the protection of biotic resources and in the development of sustained yield agroecosystems for peasants. The contributions of ethnobotanists are particularly valuable because they can find where and why useful wild species persist in agroecosystems. A greater effort to direct the attentions of policy makers to the value of ethnobotanical knowledge is needed.     

Plantation forests and biodiversity: oxymoron or opportunity?

Losses of natural and semi-natural forests, mostly to agriculture, are a significant concern for biodiversity. Against this trend, the area of intensively managed plantation forests increases, and there is much debate about the implications for biodiversity. We provide a comprehensive review of the function of plantation forests as habitat compared with other land cover, examine the effects on biodiversity at the landscape scale, and synthesise context-specific effects of plantation forestry on biodiversity. Natural forests are usually more suitable as habitat for a wider range of native forest species than plantation forests but there is abundant evidence that plantation forests can provide valuable habitat, even for some threatened and endangered species, and may contribute to the conservation of biodiversity by various mechanisms. In landscapes where forest is the natural land cover, plantation forests may represent a low-contrast matrix, and afforestation of agricultural land can assist conservation by providing complementary forest habitat, buffering edge effects, and increasing connectivity. In contrast, conversion of natural forests and afforestation of natural non-forest land is detrimental. However, regional deforestation pressure for agricultural development may render plantation forestry a ‘lesser evil’ if forest managers protect indigenous vegetation remnants. We provide numerous context-specific examples and case studies to assist impact assessments of plantation forestry, and we offer a range of management recommendations. This paper also serves as an introduction and background paper to this special issue on the effects of plantation forests on biodiversity.

Design,Efficient Synthesis,and Anti‐HIV Activity of 4′‐C‐Cyano‐ and 4′‐C‐Ethynyl‐2′‐deoxy Purine Nucleosides

Some 4′‐C‐ethynyl‐2′‐deoxy purine nucleosides showed the most potent anti‐HIV activity among the series of 4′‐C‐substituted 2′‐deoxynucleosides whose 4′‐C‐substituents were methyl, ethyl, ethynyl and so on. Our hypothesis is that the smaller the substituent at the C‐4′ position they have, the more acceptable biological activity they show. Thus, 4′‐C‐cyano‐2′‐deoxy purine nucleosides, whose substituent is smaller than the ethynyl group, will have more potent antiviral activity. To prove our hypothesis, we planned to develop an efficient synthesis of 4′‐C‐cyano‐2′‐deoxy purine nucleosides (4′‐CNdNs) and 4′‐C‐ethynyl‐2′‐deoxy purine nucleosides (4′‐EdNs). Consequently, we succeeded in developing an efficient synthesis of six 2′‐deoxy purine nucleosides bearing either a cyano or an ethynyl group at the C‐4′ position of the sugar moiety from 2′‐deoxyadenosine and 2,6‐diaminopurine 2′‐deoxyriboside. Unfortunately, 4′‐C‐cyano derivatives showed lower activity against HIV‐1, and two 4′‐C‐ethynyl derivatives suggested high toxicity in vivo.     

Thiosugar Nucleosides. Synthesis and Biological Activity of 1,3,4‐Thiadiazole,Thiazoline and Thiourea Derivatives of 5‐Thio‐d‐Glucose

New acylated 5‐thio‐β‐d‐glucopyranosylimino‐disusbstituted 1,3,4‐thiadiazols 8, and 11 were prepared, via spontaneous rearrangements, by cycloaddition of the glycosyl isothiocyanate 2 with the reactive intermediates 1‐aza‐2‐azoniaallene hexachloroantimonates 4 and 6, respectively. Reaction of 2 with aminoacetone or chloroethylamine afforded the acylated 5‐thio‐β‐d‐glucopyranosyl‐4‐imidazoline‐2‐thione nucleoside 16 and glucopyranosylamino‐2‐thiazoline derivative 18, respectively. Deblocking of 8, 11, 17 and 19 furnished the free nucleoside analogues 9, 12, 18 and 20, respectively. Analogously, treatment of 2 with chloroethylamine in the 1:2 ratio afforded the thioureylendisaccharide 21. No in vitro antiviral activity against HIV‐1, HIV‐2, human cytomegallovirus (HMCV), has been found for the new synthesized compounds.     

Does the width of isolated ravine forests influence moss and liverwort diversity and composition?—A study of temperate forests in South Africa

The evidence of microclimatic edge effects through forest/open area ecotones is firm. How this affects the species composition near edges is less well understood and documented. In south-western South Africa shrub-dominated regularly burnt vegetation (i.e. fynbos) is the most common vegetation with indigenous temperate forests naturally occurring mostly in ravines on mountain slopes. The size and width of these forest patches varies considerably. In order to understand how the width of forest patches affects species composition of mosses and liverworts we investigated 20 forest patches of different width. In each forest patch we compiled a total species list, and collected data on selected environmental variables, for a plot of 10×20 m. No significant relationship was found between patch width and the number of either moss or liverwort species. However, the species composition of mosses (but not liverworts) changed along the gradient of patch width. The variation in number of species was large (8–29 mosses and 11–33 liverworts) among the plots and we propose that factors other than distance to the forest edge may be more important in structuring the bryophyte community of these ravine forests. One such factor that is likely to be important is the climatic difference among the plots. There is variation in features, such as precipitation, summer temperature, cloudiness, and the amount of fog, for which we do not have data but that could overrule the microclimatic differences due to edge effects.     

Overweight and obesity among foreign‐born and U.S.‐born Hispanics

Abstract

In this study, data from the New Immigrant Survey and the National Health and Nutrition Examination Survey are combined to examine patterns of overweight and obesity among U.S.‐born and foreign‐born Hispanics. Results indicate that, after using height and weight measures adjusted for self‐reporting bias, foreign‐born Hispanic men and women have substantially lower likelihoods of being overweight and obese than the U.S.‐born. However, both likelihoods increase as years in the U.S. accumulate for the foreign‐born. Controls for smoking behavior, physical activity, and the degree of dietary change do not reduce the strength of the positive relationship between years in the U.S. and overweight/obesity.     

Messinian‐Zanclean vegetation and climate in North‐Central Italy

A palynological study was carried out on four Italian Miocene‐Pliocene sections ranging in age from uppermost Tortonian to Zanclean located on the Adriatic side of the North‐Central Apennines. The study documents the Mediterranean isolation, the salinity crisis (s.s), the “lago‐mare”; event and the re‐establishment of open‐marine conditions in the Mediterranean at the beginning of the Pliocene. From a climatic point of view, a transition from subtropical/warm‐temperate conditions during the Messinian to warm‐temperate/temperate conditions during the Zanclean is recorded. The presence of a lower thermic level, with respect to the Messinian, the re‐establishment of open‐marine conditions and the uplift of the Apennines were major factors controlling paleoenvironmental variations during the Zanclean. The latter is also characterized by cyclic temperature oscillations. Correlations with coeval sections in the Mediterranean area confirm the existence of latitudinal climatic gradients within the studied area.     

Synthesis of Oligoribonucleotides Containing 4‐Thiouridine Using the Convertible Nucleoside Approach and the 1‐(2‐Fluorophenyl)‐4‐Methoxypiperidin‐4‐yl Group

Oligoribonucleotides containing 4‐thiouridine were prepared using the Fpmp group for protection of the 2′‐OH. Two uridine derivatives with the 1,2,4‐triazolyl and the 2‐nitrophenyl groups at position 4 were used to obtain 4‐thiouridine by postsynthetic substitution with sodium hydrogen sulfide. Both uridine derivatives allow the preparation of the desired oligonucleotides in good yields.     

Plants‐associated microflora and the remediation of oil‐contaminated soil

The use of plants and their rhizospheric microorganisms is a promising emerging technology for remediating contaminated soils. The degradation of total petroleum hydrocarbon (TPH) in the rhizospheric and nonrhizospheric soil of three domestic plants, namely, alfalfa (Medicaga sativa) broad beans (Vicia faba) and ryegrass (Lolium perenne) was investigated. The experimental data from the studies of plantmicrobe‐soil interactions implicated the enhancement of TPH degradation by the rhizospheric microbial community. Although the three domestic plants exhibited normal growth in the presence of ～1.0% TPH, the degradation was more profound in the case of leguminous plants. The TPH degradation in the soil cultivated with broad beans and alfalfa was 36.6 and 35.8%, respectively, compared with 24% degradation in case of ryegrass. Such a high correlation between plant type and TPH degradation rates indicate that selection for enhanced rhizosphere degradation may be accomplished by selecting leguminous plants.     

Fluxes and concentrations of dissolved organic carbon and nitrogen – a synthesis for temperate forests

Dissolved organic carbon (DOC) and nitrogen (DON)represent an important part of the C and N cycles inforest ecosystems. Little is known about the controlson fluxes and concentrations of these compounds insoils under field conditions. Here we compiledpublished data on concentrations and fluxes of DOC andDON from 42 case studies in forest ecosystems of thetemperate zone in order to evaluate controls on alarger temporal and spatial scale. The focus was onannual fluxes and concentrations in throughfall,forest floor leachates and soil solutions. In allcompartments considered, concentrations and fluxesdiffered widely between the sites. Highestconcentrations of DOC and DON were generally observedin forest floor leachates and in A horizons. Highestfluxes occurred in forest floor leachates. The fluxesof DOC and DON in forest floor leachates increasedwith increasing annual precipitation and were alsopositively related to DOC and DON fluxes withthroughfall. Variation in throughfall fluxes couldexplain 46% and 65% of the variation in DOC and DONfluxes from the forest floor, respectively. No generaldifference in DOC and DON concentrations and fluxes inforest floor leachates was found when comparingconiferous and hardwood sites. Concentrations of DOCin forest floor leachates were positively correlatedto the pH of the forest floor. Furthermore, there wasno relationship between organic C and N stocks, soilC/N, litterfall or mineral N inputs and concentrationsand fluxes of DOC and DON in forest floor leachates.Including all compartments, fluxes of DOC and DON werehighly correlated. Ratios of DOC to DON calculatedfrom fluxes from the forest floor were independent ofthe amount of annual precipitation, pointing to asimilar response of DOC and DON to precipitationconditions. A decrease in the ratio of DOC to DON withsoil depth as observed on a plot-scale, was notconfirmed by data analysis on a large scale. Thecontrols observed on annual fluxes and concentrationsof DON and DOC at regional scale differed from thosereported for smaller time and space scales.     

One‐Pot Solvent Free Synthesis and DNA Binding Studies of Thieno[2,3‐b]‐1,8‐Naphthyridines

Abstract

With the aim of evaluating interaction between double‐stranded calf thymus (ds)DNA and sulphur containing fused planar rings, the derivatives of 1,8‐naphthyridine containing thiono groups were synthesized by the condensation of 2‐mercapto‐3‐formyl[1,8]naphthyridines using 1‐chloroacetone, 2‐chloroacetamide, chloroaceticacid, and 2‐chloro‐1‐phenylethanone in the presence of anhydrous potassium carbonate as s catalyst under solvent free microwave irradiation. The structures of the compounds were elucidated on the basis of elemental analysis, IR, ¹H NMR, and mass spectra. The interaction of thieno[2,3‐b]‐1,8‐naphthyridine‐2‐carboxylic acid (TNC) (3a) with ct‐DNA was studied by UV‐Vis spectrophotometry, viscosity, thermal denaturation, as well as cyclic voltammetry experiments. On binding to DNA, the absorption spectrum underwent bathochromic and hypochromic shifts. Binding parameters, determined from spectrophotometric measurements indicated a binding constant of K _b =2.1×10⁶ M^?1. The thieno[2,3‐b]‐1,8‐naphthyridine‐2‐carboxylic acid (3a) increases the viscosity of sonicated rod‐like DNA fragments. The binding of TNC to DNA increased the melting temperature by about 4°C. The decrease in peak current heights and shifts of peak potential values are observed by the addition of calf thymus DNA in cyclic voltammetry studies.     

Microbrachiopods and the end‐Ordovician event

Millimetre sized chitinophosphatic brachiopods ("microbrachiopods") largely, but by no means entirely, centred around the family Acrotretidae are commonly regarded as being in decline after the early Ordovician. Work on Irish Upper Ordovician limestones however shows that this is not the case, material recovered showing both numerical abundance and taxonomic diversity in beds of Ashgill age. Although forms are known from the Devonian, the published record of these neglected fossils from the Silurian is sparse, so that the effects, if any, of the end‐Ordovician event on this ecologically enigmatic group cannot as yet be determined.