Woodland area,species turnover and the conservation of bird assemblages in lowland England

A study over 4 years into the number of breeding bird species and species turnover (extinctions and colonisations) in relation to area was conducted in 35 woodlands, set in an intensively farmed landscape, in north-east Essex, UK. A total of 46 species was recorded. The number of species breeding increased with woodland area; the slope of the species–area relationship did not differ between years. Habitat diversity was the only other measured variable to influence species richness. Absolute species turnover was independent of woodland area but relative turnover declined with increase in woodland area. The numbers of territories of nine species were determined. For four summer visitors the number of woods occupied increased as the overall populations increased but, for the other species, changes in overall population size led to changes in numbers in occupied woods. Chaffinch Fringilla coelebs and Song Thrush Turdus philomelos were more associated with woodland edges, Nightingale Luscinia megarhynchos, Garden Warbler Sylvia borin, Chiffchaff Phylloscopus collybita and Willow Warbler P. trochilus with interiors. Several species showed an inverse relationship between population density and woodland area. Collections of small woods hold similar species richness to single large woods. While the acquisition of large woods for conservation purposes should be a priority, the extension of smaller woods to a size of about 10 ha would be highly beneficial to both the species richness and population stability of regional woodland bird assemblages.     

Bird abundance and species richness on Florida lakes: influence of trophic status,lake morphology,and aquatic macrophytes

Data from 46 Florida lakes were used to examine relationships between bird abundance (numbers and biomass) and species richness, and lake trophic status, lake morphology and aquatic macrophyte abundance. Average annual bird numbers ranged from 7 to 800 birds km^–2 and bird biomass ranged from 1 to 465 kg km^–2. Total species richness ranged from 1 to 30 species per lake. Annual average bird numbers and biomass were positively correlated to lake trophic status as assessed by total phosphorus (r = 0.61), total nitrogen (r = 0.60) and chlorophyll a (r = 0.56) concentrations. Species richness was positively correlated to lake area (r = 0.86) and trophic status (r = 0.64 for total phosphorus concentrations). The percentage of the total annual phosphorus load contributed to 14 Florida lakes by bird populations was low averaging 2.4%. Bird populations using Florida lakes, therefore, do not significantly impact the trophic status of the lakes under natural situations, but lake trophic status is a major factor influencing bird abundance and species richness on lakes. Bird abundance and species richness were not significantly correlated to other lake morphology or aquatic macrophyte parameters after the effects of lake area and trophic status were accounted for using stepwise multiple regression. The lack of significant relations between annual average bird abundance and species richness and macrophyte abundance seems to be related to changes in bird species composition. Bird abundance and species richness remain relatively stable as macrophyte abundance increases, but birds that use open-water habitats (e.g., double-crested cormorant, Phalacrocorax auritus) are replaced by species that use macrophyte communities (e.g., ring-necked duck, Aythya collaris).     

A nested-intensity design for surveying plant diversity

Managers of natural landscapes need cost-efficient, accurate, and precise systems to inventory plant diversity. We investigated a nested-intensity sampling design to assess local and landscape-scale heterogeneity of plant species richness in aspen stands in southern Colorado, USA. The nested-intensity design used three vegetation sampling techniques: the Modified-Whittaker, a 1000-m² multiple-scale plot (n = 8); a 100-m² multiple-scale Intensive plot (n = 15); and a 100-m² single-scale Extensive plot (n = 28). The large Modified-Whittaker plot (1000 m²) recorded greater species richness per plot than the other two sampling techniques (P < 0.001), estimated cover of a greater number of species in 1-m² subplots (P < 0.018), and captured 32 species missed by the smaller, more numerous 100-m² plots of the other designs. The Intensive plots extended the environmental gradient sampled, capturing 17 species missed by the other techniques, and improved species–area calculations. The greater number of Extensive plots further expanded the gradient sampled, and captured 18 additional species. The multi-scale Modified-Whittaker and Intensive designs allowed quantification of the slopes of species–area curves in the single-scale Extensive plots. Multiple linear regressions were able to predict the slope of species–area curves (adj R ² = 0.64, P < 0.001) at each Extensive plot, allowing comparison of species richness at each sample location. Comparison of species–accumulation curves generated with each technique suggested that small, single-scale plot techniques might be very misleading because they underestimate species richness by missing locally rare species at every site. A combination of large and small multi-scale and single-scale plots greatly improves our understanding of native and exotic plant diversity patterns.     

Effects of restoration with cattle grazing on plant species composition and richness of semi-natural grasslands

Restoration of semi-natural grasslands by cattle grazing is among the most practical options for reversing the decline of northern European floristic diversity, but no studies on this subject are available. In this work the success of restoration of abandoned, privately owned mesic semi-natural grasslands by farmers receiving support from the EU agri-environmental support scheme was studied in southwestern Finland. Three kinds of grasslands were compared: old (continuously cattle grazed), new (cattle grazing restarted 3–8 years ago) and abandoned pastures (grazing terminated >10 years ago). Plant species composition of the three pasture types was floristically different in multivariate analyses (non-metric multidimensional scaling). Total species richness, richness of grassland plants, indicator plants and rare plants were highest in old and lowest in abandoned pastures in all studied spatial scales (0.25–0.8 ha, 1 and 0.01 m²). The results were congruent with different scales and species list definitions, suggesting that species density scale (1 m²) can be used as a partial surrogate for large scale species richness. Species richness of new pastures was 20% higher on 0.25–0.8 ha, 40–50% higher on 1 m² and 30% higher on the 0.01 m² scale compared to abandoned grasslands. Rare species showed insignificant response to resumed grazing. Despite problems in management quality, this study showed promising results of restoration of abandoned grasslands by cattle grazing on private farms. However, populations of several rare grassland plants may not recover with present cattle grazing regimes. Management regulations in the agri-environmental support scheme need to be defined more precisely for successful restoration.     

Detecting biodiversity hotspots using species–area and endemics–area relationships: the case of butterflies

Using data of the Red Data Book of European Butterflies we establish the species–area relationship (S = 8.5 A^0.23) and the endemics–area relationship (S = 0.5 A^0.18) of European butterflies. Applying confidence limits as tools for the identification of hotspot countries we show that in the case of butterflies hotspots of endemism and hotspots of overall species richness do not coincide. We introduce plots of residuals from species–area relationships shifted upwards by the 95% confidence limits of the intercept (α-values) as a new tool for identifying and ranking of hotspots.     

Life-form species–area relationships in a temperate eucalypt woodland community

Viewing species–area curves in the context of the different life forms that generate them might be instructive for understanding why high species density develops in some plant communities. In order to evaluate the patterns of species density in an Australian temperate eucalypt woodland community, we used species–area curves and document rate of species accumulation by life forms in six nested plots ranging in size from 1 m² to 0.1 ha at 13 woodland sites. Mean total species density was 82 ± 3.8 species at 0.1 ha scales (range 49–104 species), making them amongst the most diverse woodlands in Australia at these spatial scales. Species–area relationships for total species were best described by power function models (log–log linear) with slopes (z) ranging from 0.12 to 0.35 (mean = 0.17 ± 0.02). When species were analysed by life form, species–area relationships were similarly well-described by the power function for all life forms, although their slopes differed significantly; annuals had the lowest slope and woody species the highest. Annuals and perennial herb species density were equal at the smallest spatial scales (mean 11.7 and 11.5 species/m², respectively) and hence, both life forms help generate high small scale species density. Small-scale total species density, but not individual life form, was a significant predictor of larger-scale total species density (r ² = 0.36, P = 0.03). Our findings suggest that high species density may be a general property of temperate eucalypt woodlands with herbaceous understoreys and that the mechanisms that underpin these patterns require further study.     

Effects of removal and regeneration of bankside vegetation on fish population dynamics in the Warta River,Poland

In March 1989 both banks of a 450 m section of the Warta River, 2 km above a reservoir, were cleared of their riparian vegetation (osiers, willows and alders). In October 1988 17 fish species had been recorded there, with a standing crop (SC) of 31.9 kg ha ^–1. In April 1989, the number of species decreased to 11, and their SC to 7.9 kg ha ^–1.Over the next three years new alder trees appeared and osiers regrew to 3.5 m. The SC in October 1990, October 1991 and May 1992 was recorded at 36.5, 66.2 and 40.9 kg ha ^–1, respectively. The primary effect was on phytophils, whose biomass was directly proportional to the height of the trees and osiers (r = 0.87, p = 0.05). The litho-phytophils appeared to occupy the habitat vacated by the phytophils soon after bank clearance (r = –0.87, p = 0.05), but then declined as the osiers grew.     

Tree diversity and distribution in undisturbed and human-impacted sites of tropical wet evergreen forest in southern Western Ghats, India

The composition, abundance, population structure and distribution patterns of all woody species ( 30 cm gbh) were investigated in an undisturbed and two adjacent human-impacted sites of a tropical wet evergreen forest in Kalakad National Park, Western Ghats, south India. Three 1-ha plots were established, one each in (i) an undisturbed site (named site UD), (ii) in a site selectively felled 35 years ago (site SF – small stems felled leaving the large trees (as shade) for developing it into a cardamom estate, on the failure of which the site was abandoned) and (iii) a frequently disturbed site (site FD – round woods logged for use in ovens for curing cardamom). These sites are 1 to 3 km apart in the same wet evergreen forest. In the three study plots a total of 2150 stems (mean density 716 ha^–1) covering 122 species in 89 genera and 41 families were enumerated. Species richness was greatest (85 species ha^–1) in the undisturbed site UD, intermediate (83) in SF and lowest (80) in FD. Tree density was greatest (855 stems ha^–1) in site SF, intermediate (720) in UD and lowest (575) in FD. The forest stand was exceptionally voluminous in site UD (basal area 94.64 m² ha^–1), intermediate (66.9 m²) in SF and least (61.7 m²) in FD, due to tree removal for fuel in the latter sites. Species composition and abundance patterns markedly varied between the three sites. In UD and SF, primary forest species (Cryptocarya bourdillonii , Cullenia exarillata Myristica dactyloides etc.) occurred in greater density. In FD heliophilic secondary forest species (Elaeocarpus venustus, Litsea wightiana, Viburnum punctatum and Vitex altissima) were abundant, while these were absent in UD and SF. The species–area curve did not reach an asymptote in any of the sites on the 1-ha scale. The stand population structure was clearly reverse J shaped in UD and SF, while small stems were 2- to 3-fold fewer in FD. Most trees exhibited clumped distribution of individuals on the 1-ha scale. Variation in the kind and richness of species and their abundance is related to human interference and the need for forest conservation is emphasized.     

Plant communities and landscape diversity along a Canadian Arctic river

Abstract. We analysed the structure and diversity of the vegetation along an Arctic river to determine the relationship between species richness and plant community structure. We examined whether variation in species richness along the corridor is structured as (1) an increase in the number of communities due to increasing landscape heterogeneity, (2) an increase in the floristic distinctiveness (β-diversity) of communities, or (3) an increase in within-community richness (α-diversity) as species-poor communities are replaced by species-rich communities. We described 24 community types and analysed the relationship between site vascular species richness (γ-diversity) and β-diversity, α-diversity, site environmental heterogeneity, and the number of distinct plant communities. We also measured diversity patterns of vascular, bryophyte, and lichen species within communities and examined their relationship to community-level estimates of environmental factors. We found that an increase in site species richness correlated with an increase in the number of communities (r²= 0.323, P= 0.0173) and β-diversity (r²= 0.388, P= 0.0075), rather than an increase in the α-diversity of individual communities. Moisture and pH controlled most of the differences in composition between communities. Measures of species richness and correlations with moisture and pH within communities differed among vascular, bryophyte, and lichen species. Bryophyte richness was positively correlated with moisture (r²= 0.862, P= 0.0010) and lichen richness was negatively correlated with moisture (r²= 0.809, P= 0.0031). Vascular plants had a peak in richness at pH 6.5 (r²= 0.214, P < 0.0001). We conclude that site variation in vascular richness in this region is controlled by landscape heterogeneity, and structured as variation in the number and distinctiveness of recognizable plant communities.     

Species diversity and dominance in the planktonic rotifer community of the Pripyat River in the Chernobyl region (1988–1996)

Here, we report the results of monitoring the rotifer community in the Pripyat River within the 30-km evacuation zone of the Chernobyl Nuclear Power Plant over the period 1988–1996. While radionuclide concentration in water did not exceed 4.07 Bq l^–1, the radioactivity in the bottom sediment was quite high, varying irregularly between 113 and 824 kBq m². Radionuclide concentration in the seston also ranged widely: riverbed = 659–2491; backwater = 168–32 832 Bq kg^–1. The rotifer density varied in the range of 65–17 970 individuals l^–1. Sixty-seven rotifer species were identified in the Pripyat, with nine species being previously unknown to this river. Species richness (jackknife estimate) in both the riverbed and the backwater stations was similar and was characterized by a very great variability: riverbed = 66.1 (df=20, SD=39.50); back-water = 66.2 (df=20, SD=42.17). Correlation between the heterogeneity of rotifer community (H ^') and the number of species and relative density of the dominant species was evident. The degree of statistical interrelation between H ^' and relative density of the dominant species was especially high in the riverbed station (r ²= 0.74, p= 0.00001). However, no significant correlation between radionuclide concentration and rotifer biodiversity was found.     

Diversity of understory plants in undisturbed and disturbed tropical lowland forests of Little Andaman Island, India

Species richness and density of understory plants were investigated in eight 1 ha plots, distributed one each in undisturbed and disturbed tropical evergreen, semi-evergreen, deciduous and littoral forests of Little Andaman island, India, which falls under one of the eight hottest hotspots of Biodiversity in the world viz. the Indo-Burma. One hundred 1 m⁻² quadrats were established in each 1 ha plot, in which all the understory plants (that include herbs, undershrubs, shrubs and herbaceous climbers) were enumerated. The total density of understory plants was 6,812 individuals (851 ha⁻¹) and species richness was 108 species, representing 104 genera and 50 families. Across the four forest types and eight study plots, the species richness ranged from 10 to 39 species ha⁻¹. All the disturbed sites harbored greater number of species than their undisturbed counterparts. Herbs dominated by species (63%) and density (4,259 individuals). The grass Eragrostis tenella (1,860 individuals; IVI 40), the invasive climber Mikania cordata (803; IVI 20) and the shrub Anaxagorea luzonensis (481; IVI 17.5) were the most abundant species. Poaceae, Asteraceae, Acanthaceae, Orchidaceae and Euphorbiaceae constituted the species-rich families represented by 6 species each. The species-area curves attained an asymptote at 0.8 ha level except in sites DD and DL, indicating 1 ha plot is not sufficient to capture all the understory species in disturbed forests. The alien weeds formed about one-fourth of the species richness (31 species; 28%) and density (1,926 individuals; 28.3%) in the study sites, indicating the extent of weed invasion and the attention required for effective conservation of the native biodiversity of the fragile island forest ecosystem.     

The Influence of Vegetation Height Heterogeneity on Forest and Woodland Bird Species Richness across the United States

Avian diversity is under increasing pressures. It is thus critical to understand the ecological variables that contribute to large scale spatial distribution of avian species diversity. Traditionally, studies have relied primarily on two-dimensional habitat structure to model broad scale species richness. Vegetation vertical structure is increasingly used at local scales. However, the spatial arrangement of vegetation height has never been taken into consideration. Our goal was to examine the efficacies of three-dimensional forest structure, particularly the spatial heterogeneity of vegetation height in improving avian richness models across forested ecoregions in the U.S. We developed novel habitat metrics to characterize the spatial arrangement of vegetation height using the National Biomass and Carbon Dataset for the year 2000 (NBCD). The height-structured metrics were compared with other habitat metrics for statistical association with richness of three forest breeding bird guilds across Breeding Bird Survey (BBS) routes: a broadly grouped woodland guild, and two forest breeding guilds with preferences for forest edge and for interior forest. Parametric and non-parametric models were built to examine the improvement of predictability. Height-structured metrics had the strongest associations with species richness, yielding improved predictive ability for the woodland guild richness models (r² = ∼0.53 for the parametric models, 0.63 the non-parametric models) and the forest edge guild models (r² = ∼0.34 for the parametric models, 0.47 the non-parametric models). All but one of the linear models incorporating height-structured metrics showed significantly higher adjusted-r² values than their counterparts without additional metrics. The interior forest guild richness showed a consistent low association with height-structured metrics. Our results suggest that height heterogeneity, beyond canopy height alone, supplements habitat characterization and richness models of forest bird species. The metrics and models derived in this study demonstrate practical examples of utilizing three-dimensional vegetation data for improved characterization of spatial patterns in species richness.     

Tree species richness complementarity, disturbance and fragmentation in a Mexican tropical montane cloud forest

Tropical montane cloud forest exhibits great heterogeneity in speciescomposition and structure over short geographic distances. In central Veracruz,Mexico, the conservation priority of seven cloud forest fragments was assessedby considering differences in woody plant species richness and complementarityof species among sites, forest structure, tree mortality, and timber andfirewood extraction as indicators of anthropogenic disturbance. Densities oftrees 5 cm dbh (360–1700 trees/ha) weredifferent among the sites, but basal area (35.3–89.3m²/ha) did not differ among fragments. The number of dead trees rangedfrom 10–30 to 170–200 trees/ha. The fragments'species composition was different but complementary. The Morisita–Hornindex indicated low similarity between fragments. A non-parametric estimator ofspecies richness indicated that more sampling effort would be necessary tocomplete the inventory (15 additional trees and two understory shrub species).Unfortunately, most of the fragments are threatened with deforestation. The numberof cut trees was similar among sites (0–15 cut trees/0.1 ha).Sites with immediate need for conservation were close to settlements, with highnumbers of cut trees and no legal protection. The selected sites represent thevariety of situations that exist in the region. Given the high complementarityobserved between fragments, a regional conservation approach will be required topreserve the last repositories of part of the tremendous biodiversity of theonce continuous forest in this region.     

A probability-based indicator of ecological condition

We introduce a new method for quantifying the ecological condition (C) of sites based on documented species’ responses to environmental stress. Preliminary research is needed to establish species-specific logistic functions, representing probabilities of finding individual species across an explicit reference gradient, ranging from maximally stressed (C = 0) to minimally stressed (C = 10) localities. Each function takes into account the species’ tolerance to stress, the species’ overall ubiquity, and the probability of detecting the species when it is present. Given a set of standardized species-specific functions, the ecological condition of any site can be derived by iteration, converging on the value of C that best “predicts” the species that are actually present. Species from multiple taxonomic groups can be included in the calculations, and results are not directly affected by species richness or sampling area. We demonstrate a successful application of this method for bird species assemblages in the U.S. portion of the Great Lakes coastal zone. Approximately, 28% of the bird species observed in the Eastern Deciduous Forest Ecological Province and 35% of the species in the Laurentian Mixed Forest Ecological Province showed strong relationships with a reference gradient of land cover variables. Functional stress–response relationships of these species can be used effectively to estimate ecological condition at new sites. The estimated condition based on bird species generally mirrors the reference condition, but deviations from the expected 1:1 relationship provide meaningful insights about ecological condition of the target areas. Sensitivity analysis using different numbers of species shows that our method is robust and can be applied consistently with 25–30 species exhibiting strong stress–response functions.     

Hyperspectral Remote Sensing of Canopy Biodiversity in Hawaiian Lowland Rainforests

Mapping biological diversity is a high priority for conservation research, management and policy development, but few studies have provided diversity data at high spatial resolution from remote sensing. We used airborne imaging spectroscopy to map woody vascular plant species richness in lowland tropical forest ecosystems in Hawai’i. Hyperspectral signatures spanning the 400–2,500 nm wavelength range acquired by the NASA Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) were analyzed at 17 forest sites with species richness values ranging from 1 to 17 species per 0.1–0.3 ha. Spatial variation (range) in the shape of the AVIRIS spectra (derivative reflectance) in wavelength regions associated with upper-canopy pigments, water, and nitrogen content were well correlated with species richness across field sites. An analysis of leaf chlorophyll, water, and nitrogen content within and across species suggested that increasing spectral diversity was linked to increasing species richness by way of increasing biochemical diversity. A linear regression analysis showed that species richness was predicted by a combination of four biochemically-distinct wavelength observations centered at 530, 720, 1,201, and 1,523 nm (r ² = 0.85, p < 0.01). This relationship was used to map species richness at approximately 0.1 ha resolution in lowland forest reserves throughout the study region. Future remote sensing studies of biodiversity will benefit from explicitly connecting chemical and physical properties of the organisms to remotely sensed data.     

Species Richness and Patterns of Invasion in Plants, Birds, and Fishes in the United States*

We quantified broad-scale patterns of species richness and species density (mean # species/km²) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines in potential evapotranspiration, mean temperature, and precipitation. County data on plants (n = 3004 counties) and birds (n=3074 counties), and drainage (6 HUC) data on fishes (n = 328 drainages) showed that the densities of native and non-indigenous species were strongly positively correlated for plant species (r = 0.86, P < 0.0001), bird species (r = 0.93, P<0.0001), and fish species (r = 0.41, P<0.0001). Multiple regression models showed that the densities of native plant and bird species could be strongly predicted (adj. R² = 0.66 in both models) at county levels, but fish species densities were less predictable at drainage levels (adj. R² = 0.31, P<0.0001). Similarly, non-indigenous plant and bird species densities were strongly predictable (adj. R² = 0.84 and 0.91 respectively), but non-indigenous fish species density was less predictable (adj. R² = 0.38). County level hotspots of native and non-indigenous plants, birds, and fishes were located in low elevation areas close to the coast with high precipitation and productivity (vegetation carbon). We show that (1) native species richness can be moderately well predicted with abiotic factors; (2) human populations have tended to settle in areas rich in native species; and (3) the richness and density of non-indigenous plant, bird, and fish species can be accurately predicted from biotic and abiotic factors largely because they are positively correlated to native species densities. We conclude that while humans facilitate the initial establishment, invasions of non-indigenous species, the spread and subsequent distributions of non-indigenous species may be controlled largely by environmental factors. The U.S. Government’s right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged.     

Vogelbest?nde kultivierten Feuchtlandes Schleswig-Holsteins im Jahreslauf

Zusammenfassung Die Arbeit behandelt Vogelbestände im Niederungen-Grünland Schleswig-Holsteins. Die Jahresvogel-Bestände wurden auf 2 Untersuchungsflächen mit insgesamt 6,8 km² ermittelt (1976–1984). Zur Hochrechnung ausgewählter Gesamtbestände sind weitere Gebiete (Vergleichsflächen) einbezogen, summarisch bis zu 219 km² (bis 1993). Die Gesamtartenzahl beträgt 92 (Jahresmittel 37,4). Das jährliche Artenspektrum besteht zu 28% aus Brutvögeln und 72% aus Nicht-Brutvögeln (je 36% Brutvögel der Umgebung und Durchzügler/Gäste). Die mittlere Individuendichte beträgt 48,1/10 ha. Einmal im Jahr findet ein nahezu vollständiger Austausch von Nicht-Brutvögeln und (heimischen) Brutvögeln statt. Für dominierende und charakteristische Arten werden landesweit Bestände geschätzt. Im Winter bildet Grünland gegenüber anderen Agrarflächen ein sehr attraktives Habitat.

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Seasonal changes in bird communities of cultivated wetlands in Schleswig-Holstein/Germany

Summary The number of bird species and individuals were determined in 2 study plots (total 6,8 km² and 105 counts) in cultivated lowlands (grassland) of Schleswig-Holstein during 1976–1984. In order to estimate the total population of selected species additional comparison sites were surveyed. In total up to 219 km² (up to 1993) were surveyed. The average number of species observed each year was 37,4. On average 28% of the birds recorded each year were breeding species and 72% were non-breeders (of these 36% were breeding birds of the surrounding villages and woods and 36% were migrants and visitors). The average abundance was 48,1 individuals/10 ha. An almost complete exchange of non-breeders and local breeding birds occurs once a year. Estimated population sizes of dominant and characteristic species in Schleswig-Holstein are presented. Some lowland sites are very attractive habitats of international importance especially during the winter.

     

Decomposition and nutrient release by green manures in a tropical hillside agroecosystem

The decomposition and nutrient release of 12 plant materials were assessed in a 20-week litterbag field study in hillsides from Cauca, Colombia. Leaves of Tithonia diversifolia (TTH) and Indigofera constricta (IND) decomposed quickly (k=0.035±0.002 d^–1), while those of Cratylia argentea (CRA) and the stems evaluated decomposed slowly (k=0.007±0.002 d^–1). Potassium presented the highest release rates (k>0.085 d^–1). Rates of N and P release were high for all leaf materials evaluated (k>0.028 d^–1) with the exception of CRA (N and P), TTH and IND (P). While Mg release rates ranged from 0.013 to 0.122 d^–1, Ca release was generally slower (k=0.008–0.041 d^–1). Initial quality parameters that best correlated with decomposition (P>0.001) were neutral detergent fibre, NDF (r=–0.96) and in vitro dry matter digestibility, IVDMD (r=0.87). It is argued that NDF or IVDMD could be useful lab-based tests during screening of plant materials as green manures. Significant correlations (P>0.05) were also found for initial quality parameters and nutrient release, being most important the lignin/N ratio (r=–0.71) and (lignin+polyphenol)/N ratios (r=–0.70) for N release, the C/N (r=0.70) and N/P ratios (r=–0.66) for P release, the hemicellulose content (r=–0.75) for K release, the Ca content (r=0.82) for Ca release, and the C/P ratio (r=0.65) for Mg release. After 20 weeks, the leaves of Mucuna deerengianum released the highest amounts of N and P (144.5 and 11.4 kg ha^–1, respectively), while TTH released the highest amounts of K, Ca and Mg (129.3, 112.6 and 25.9 kg ha^–1, respectively). These results show the potential of some plant materials studied as sources of nutrients in tropical hillside agroecosystems.     

The influence of phylogeny and life history on telomere lengths and telomere rate of change among bird species: A meta‐analysis

Longevity is highly variable among animal species and has coevolved with other life‐history traits, such as body size and rates of reproduction. Telomeres, through their erosion over time, are one of the cell mechanisms that produce senescence at the cell level and might even have an influence on the rate of aging in whole organisms. However, uneroded telomeres are also risk factors of cell immortalization. The associations of telomere lengths, their rate of change, and life‐history traits independent of body size are largely underexplored for birds. To test associations of life‐history traits and telomere dynamics, we conducted a phylogenetic meta‐analysis using studies of 53 species of birds. We restricted analyses to studies that applied the telomere restriction fragment length (TRF) method, and examined relationships between mean telomere length at the chick (Chick TL) and adult (Adult TL) stages, the mean rate of change in telomere length during life (TROC), and life‐history traits. We examined 3 principal components of 12 life‐history variables that represented: body size (PC1), the slow–fast continuum of pace of life (PC2), and postfledging parental care (PC3). Phylogeny had at best a small‐to‐medium influence on Adult and Chick TL (r ² = .190 and .138, respectively), but a substantial influence on TROC (r ² = .688). Phylogeny strongly influenced life histories: PC1 (r ² = .828), PC2 (.838), and PC3 (.613). Adult TL and Chick TL were poorly associated with the life‐history variables. TROC, however, was negatively and moderate‐to‐strongly associated with PC2 (unadjusted r = −.340; with phylogenetic correction, r = −.490). Independent of body size, long‐lived species with smaller clutches, and slower embryonic rate of growth may exhibit less change in telomere length over their lifetimes. We suggest that telomere lengths may have diverged, even among closely avian‐related species, yet telomere dynamics are strongly linked to the pace of life.     

Tree diversity in sacred groves of the Jaintia hills in Meghalaya, northeast India

Biodiversity of woody species was investigated in Ialong and Raliangsacred groves of the Jaintia hills in Meghalaya, northeast India. These grovesrepresent the climax subtropical broad-leaved forest of the area. A total of 738individuals belonging to 82 species, 59 genera and 39 families was identified ina 0.5 ha plot of the Ialong sacred grove, whereas the same area in theRaliang sacred grove had 469 individuals of 80 species, 62 genera and 41families. About 32% species were common to both groves. Lauraceae, with10–17 species, was the dominant family. The canopy and subcanopy stratawere respectively composed of 28 and 33% of the total tree species in theforest. The number of species as well as stem density were greater for the treesof lower dbh (5–15 cm) class compared to the higher (> 66cm) dbh class. The majority of the species showed a contagiousdistribution pattern and low frequency. The basal area varied from 57.4 to 71.4m² ha^–1. Species richness within theforest varied from 3 to 15 per 100 m² in Ialong and 3 to 12 per 100m² in Raliang. The dominance–distribution curves showed highequitability and low dominance in both groves.