Plants as indicators of wetland water source

At the local scale, plant species distribution is determined primarily by the environmental characteristics of a site. In a wetland, water chemistry and hydroperiod are two of the most important of these environmental characteristics. Both are functions of water source. In central Pennsylvania, groundwater input tends to be continuous, while surface water may be permanent or seasonal. The chemistry of groundwater and surface water differs since groundwater is influenced by the substrate through which it flows. Because of these differences, and because of their effects on plant species distribution, it is possible to use vegetation as an indicator of the dominant water source of a site. Plots within 28 wetlands in central Pennsylvania were sampled, and the plots were classified by water source. The three hydrologic categories were groundwater, seasonal surface water, and permanent surface water. The core of the study was the analysis of half of the plots to identify species that were associated with a particular water source. Several groups of indicator species were identified. Some species, including Nyssa sylvatica, were strongly associated with the presence of groundwater. Others, such as Symplocarpus foetidus, were strongly associated with the presence of seasonal surface water. Several aquatic species were associated with permanent surface water. The remainder of the plots were used to test the predictive ability of the indicator species identified. The vegetation of a wetland plot predicted its hydrologic category with 72% accuracy. The identification of more indicator species could lead to the development of a useful tool for wetland research and management, since monitoring hydrology is often both expensive and time-consuming.     

Monitoring rangeland biodiversity: Plants as indicators

Abstract As well as being important components of biodiversity in their own right, plants reflect the physical environment, are the primary target of many of the pressures acting on rangelands, and are relatively amenable to measurement. Hence, measurements based on plants have considerable potential to be efficient indicators of the response of rangeland biodiversity to land use. A recent report commissioned by the National Land and Water Resources Audit recommended a core set of 11 indicators, six of which relied on measurements of plants. These were trends in (i) the extent of clearing; (ii) the cover of native perennial ground‐layer vegetation; (iii) the distribution and abundance of exotic plant species; (iv) the distribution and abundance of fire‐sensitive species; (v) the distribution and abundance of grazing‐sensitive species; and (vi) the distribution and abundance of listed threatened entities. Most indicated responses of plants to pressures acting on them. Only two (clearing and exotic plants) related to pressures. We recommend that the set be expanded to include two additional pressure indicators, one for grazing and another for fire, in recognition of their extent and potential influence on rangeland biodiversity. We also recommend that benchmark sites be included in all ground‐based monitoring programmes to provide reference standards for those biotic indicators about which little is known. Assessments of the current state of knowledge about these indicators for two case‐study regions, the Gascoyne–Murchison strategy area and Cape York Peninsula, have shown that it would be possible to monitor most of them directly at regional scales, but that current monitoring programmes fall short of achieving this.     

Modern pollen assemblages as climate indicators in southern Europe

Aim and Location Our aim is to develop pollen–climate inference models for southern Europe and to test their performance and inference power by cross‐validation with modern climate data. Surface sediments collected from lakes along a climate gradient from the winter‐cold/summer‐wet Alps to winter‐wet/summer‐dry Sicily were analysed for modern pollen assemblages. Methods For each lake, mean monthly temperatures, seasonal precipitation and site‐specific climate uncertainties have been estimated. Pollen–climate relationships were studied using numerical analyses, and inference models were derived by partial least squares (PLS) and weighted‐averaging PLS (WA‐PLS) regressions for January and July temperatures (T), and for winter, spring and summer precipitation (P). In order to assess whether these variables are also of ecological importance for vegetation in the subregions, we split the data set into an Alpine and a Mediterranean subset. Results Low bootstrap cross‐validated root mean square errors of prediction (RMSEP) for January T (1.7 °C), July T (2.1 °C) and summer P (38 mm), as well as low RMSEPs expressed as a percentage of the gradient length (8–9%), indicate a good inference power. Models revealed excellent to good performance statistics for January T, July T and summer P (r²= 0.8), and for winter and spring P (r²=c. 0.5). We show that the variables with the highest explanatory power differ between the two subregions. These are summer T and P for the Alpine set, and January T, winter P and July T for the Mediterranean set. Main conclusions The study reveals the influence of climatic conditions during the growing season on modern pollen assemblages and indicates the potential of pollen data for long‐term climate reconstructions of parameters such as winter precipitation and temperature, which seem to be the main factors having an influence on the variability of Mediterranean climate. These models may therefore provide important information on past regional climate variability in southern Europe.     

Corticolous lichens as environmental indicators in urban areas in southern Brazil

Lichens are considered bioindicators and, as such, are widely used for air quality monitoring, especially in urban-industrial areas. The present paper proposes an evaluation of lichen communities in urban areas. The corticolous lichen community was assessed at 29 sampling stations in the city of Porto Alegre, in addition to a reference area located in the State Park in the city of Viamão, southern Brazil. The rubber band method was used for lichen mapping; three hundred host-trees were analyzed, at 11 different height levels. Lichens were evaluated in terms of composition, richness, cover and diversity, and sampling stations were classified based on the Index of Atmospheric Purity (IAP) complemented by the Environmental Classification Factor (ECF). The inclusion of ECF as a complement to the original IAP formula is proposed in the present study and not only richness and cover components are considered, but also data on the lichenized mycota composition (considering its different morphological forms). One hundred and thirty-one (131) taxa have been identified, out of which 13 specimens may be considered as indicators of urban areas, and the predominance of taxa belonging to the crustose and foliose morphological group was verified. The sampling stations were classified into five zones, ranging from lichen-free zones to optimal zones for lichen development. The use of lichen proved to be efficient to both evaluate air quality and identify alterations of urban microclimates. The application of an ECF-based correction factor is expected to complement the use of IAP, making it a more sensitive index, since an analysis of a multivaried information profile was deemed necessary, especially in regions where specimen diversity is higher.     

Medium-scale mapping of vegetation in mountains of southern Siberia

An ecophytocenotic map has been compiled for southern Siberia at a scale of 1 : 1 000 000. The legend for mountainous areas includes information on the vegetation of the mapped units and environmental conditions (Σ _t > 10°, annual precipitation, altitudes above sea, and topographic features).     

Feathers of birds of prey as indicators of mercury contamination in southern Finland

Mercury levels in feathers of nestling (162 broods) and fully-grown individuals (n = 48) were studied. Within feather variation was considerable in many individual flight feathers. In juv. ospreys the mercury levels in distal parts of secondary coverts were significantly higher than those in proximal parts (p<0.01). In total feathers, the mercury levels were higher and their variations were larger in ad. than in juv. accipiters. Various irregularities in the mercury levels in different parts of the plumage of a bird seem to support the hypothesis that the mercury in the food eaten during feather growth considerably affects the mercury levels of the feathers, while the regular trends mainly support the hypothesis that the amount of mercury stored in body tissues is a determining factor of plumage levels. The importance of these factors seems to vary depending particularly on the age of the birds. From the result of this study, feathers as indicators of environmental mercury pollution should preferably be from nestlings. Small feathers are preferable to larger ones, and total feathers should be analysed rather than only parts of them.     

Dung beetle communities as biological indicators of riparian forest widths in southern Brazil

Riparian forests provide important habitat for many wildlife species and are sensitive to landscape change. Among terrestrial invertebrates, dung beetles have been used to investigate the effects of environmental disturbances on forest structure and diversity. Since many studies demonstrated a negative response of dung beetle communities to increasing forest fragmentation, and that most dung beetle species had a more pronounced occurrence during warmest seasons, three hypotheses were tested: (1) Scarabaeinae richness, abundance, diversity and evenness are lower in thinner riparian zone widths than in wider widths during the warmest seasons; (2) Scarabaeinae richness and abundance are positively influenced by leaf litter coverage and height and canopy cover; and (3) Scarabaeinae composition varies with the reduction in riparian vegetation and among annual seasons. We selected four fragments with different riparian zone widths in three secondary streams in southern Brazil. In each fragment, four sampling periods were carried out seasonally between spring 2010 and winter 2011. We collected dung beetles using pitfall traps with two types of bait. We collected 1289 specimens distributed among 29 species. In spring and summer, dung beetle richness was higher in fragments with the widest riparian zone than in those with a thinner riparian zone, and it did not vary between fragments in fall and winter seasons. Dung beetle abundance did not differ among fragments with different riparian zone widths, but it was higher in spring and summer than fall and winter. Richness and abundance were positively influenced by leaf litter. While dung beetle diversity was higher in fragments with wider riparian zone widths than in those with thinner widths, the evenness was similar among fragments. Dung beetle composition differed between the fragments with the widest and thinnest riparian zones, and it also varied among the seasons. Our results suggest that decreased riparian zones affect negatively to dung beetle community structure in southern Brazil. Fragments with thinner riparian zones had lower beetle richness in warmest seasons and an altered community composition. In this sense, the dung beetles are potentially good indicators of riparian forest fragmentation since some species were indicators of a particular riparian zone width. From a conservation perspective, our results demonstrate that the new Brazilian Forest Code will greatly jeopardize not only the terrestrial and aquatic biodiversity of these ecosystems, but also countless other ecological functions.     

Arbutus unedo L. communities in southern Iberian Peninsula mountains

Arbutus unedo L. communities in the southern part of the Iberian Peninsula (Spain and Portugal) were studied, highlighting the differences regarding their floristic composition, biological diversity and plant dynamics according to the dominant geological substratum. Firstly, this type of formation on the little-known decarbonated calcareous substrata was analysed using classification techniques. Later, they were compared to the remaining phytocoenoses in the southern part of the Iberian Peninsula using an ordination analysis. As a result, a new suballiance is proposed together with two plant associations, which will enable us to characterize the strawberry tree groves growing on carbonated substrata and those already proposed for siliceous substrata are confirmed.     

皖南山区维管植物多样性研究

皖南山区地形复杂,生境多样,有维管植物2 342种、隶属198科913属。本区植被水平地带从北到南植被组成日趋复杂,南方成分和蕨类植物明显增多,阔叶林常见,但均呈小块状分布,常绿、落叶阔叶混交林面积逐渐减小,常绿阔叶林面积随之增大。垂直分布明显,从下至上依次是农耕区,常绿阔叶林,常绿、落叶阔叶混交林,落叶阔叶林,山地灌丛或山地草甸,基带以常绿阔叶林为主,推测其原始植被更是如此,并随着纬度的升高,其植被类型分布的上限随之降低。科的分布区类型以热带-亚热带、热带-温带分布占优势,其科的分布类型分别占31.8%与23.6%;属的分布区类型显示温带分布占50.7%处于优势,热带分布占36.6%,其中北温带和泛热带成分各自占了19.6%与18.6%,科属统计数据的差异性,以及本区草本植物含59.0%占优势等,都显示本区区系具有亚热带向暖温带过渡的双重性质,说明皖南山区是亚热带向暖温带过渡的重要地带。皖南山区古老成分众多,有单种科3科,单种属和寡种属丰富,各有65与133属,分占总属数的7.1%与14.6%。特有属、种众多,有特有属29个,占总属数的3.5%,低于全国特有属所占比例7.1%,有安徽特有被子植物25种,皖、浙、赣三省交界处特有蕨类4种,被子植物81种。本区还蕴藏丰富的食用、药用、工业与观赏用等经济植物,但一些种特别是药用植物的种质资源正逐渐减少,应加大保护力度。     

Plants and testate amoebae as environmental indicators in cupriferous peatlands,New Brunswick,Canada

Vegetation, testate amoebae, and metal concentrations in water and soil (mostly peat) were studied in two copper-rich treed swamps located north of Sackville, New Brunswick, Canada. One of the sites is partly disturbed, characterized by bare soil nearly devoid of vegetation cover except for isolated patches of the moss species, Pohlia nutans, around seepages and small streams. Copper concentrations in soil and water samples were high but varied among plots. Values in soil samples were as high as 16,000 μg/g in the open area, with 4550 μg/g being the mean. The highest value in groundwater was 1540 μg/l, with 292 μg/l being the mean. Twenty-seven testate amoebae species were identified from soil samples. The most abundant species were Cyclopyxis arcelloides and Centropyxis spp. Principal component analysis and detrended correspondence analysis showed that their abundance was especially high in the open area where copper concentrations were high, while species diversity of testate amoebae was low in the open area. This study suggests potential use of mosses and testate amoebae as bio-indicators and bio-monitoring tools for metals such as copper.     

Modern pollen and vegetation relationships in the mountains of southern California,USA

The relationship between modern pollen assemblages and modern vegetation along two elevational transects within the Transverse and Peninsular Ranges of southern California, USA, is demonstrated using cluster analysis of the pollen data. Cluster analysis separates the Sonora Desert vegetation, Valley grassland/agricultural land and chaparral vegetation types on the San Jacinto Mountains transect. Chaparral is not easily separated on the San Bernardino Mountains transect, probably due to the presence of Quercus dumosa (scrub oak) there. The lower montane Quercus – Pinus (oak – pine) community is distinct from other forest types, and can be subdivided palynologically based upon relative importance of Quercus, Pinus and Cupressaceae [primarily Calocedrus decurrens (incense cedar)] pollen. Subdivisions include Quercus – Pinus – Cupressaceae, Quercus – Cupressaceae – Pinus and Quercus – Pinus assemblages. Higher elevation Pinus – Abies (pine – fir) and Pinus-dominated communities are also differentiated from one another, although the subalpine vegetation type only occurs on the San Bernardino Mountains transect. Though the study area presently straddles a transition between winter-wet and summer-wet climatic regimes, differences between the pollen assemblages in the two mountain ranges are minimal. Pollen assemblages from lower elevations document the effects of human activities, primarily agriculture, on the modern pollen rain of the region, with the occurrence of introduced citrus (Citrus sp.) and shade (Eucalyptus sp.) trees and weedy disturbance indicators (e.g., Brassicaceae).     

Habitat selection by wolvesCanis lupus in the uplands and mountains of southern Poland

Using data from the National Wolf Census, carried out in Poland in 2000–2001, and GIS techniques we analysed habitat selection by wolvesCanis lupus Linnaeus, 1758 in uplands and mountains of southern Poland. We compared ten habitat variables and two parameters related to wolf abundance in 52 circular plots (154 km² each) with recorded wolves and 97 randomly selected plots with no signs of wolf presence. Wolf plots were characterized by higher elevation and closer location to the state border than wolf-free plots. Furthermore, wolf plots had higher forest cover, but smaller number of villages and towns and shorter railways and roads than plots without wolves. The best model explaining wolf distribution included forest cover, number of villages, length of roads and railway lines. Compared to northern Poland, the southern part of the country offers worse habitats for wolves due to significantly denser network of settlements and transportation routes.     

Physiological indicators of nutrient deficiency in phytoplankton in southern Chilean lakes

We assessed the nutrient status of phytoplankton in 28 lakes in southern Chile using two types of physiological indicators: specific alkaline phosphatase activity, and the elemental composition (carbon, nitrogen, and phosphorus) of seston. Alkaline phosphatase activity ranged from 0.001 to 0.11 mol P g chl^–1 h^–1, with P-deficiency indicated in about one-half the study lakes. C:N ranged from 3.9 to 24, C:P ranged from 86 to 919, and N:P ranged from 8.7 to 99. C:P and N:P ratios greater than the Redfield ratio were common, suggesting P deficiency in many of the lakes. C:N ratios were not generally indicative of N deficiency. Previous studies have suggested N may be the primary limiting nutrient in southern Chilean lakes, but our results indicate that P should not be discounted as a limiting nutrient.     

Taxonomy of carex sect. atratae (cyperaceae) in the southern rocky mountains

The sectionAtratae is highly differentiated in the southern Rocky Mountain region where the group has developed several endemic species. Eleven species are recognized, and three new combinations are proposed:C. parryana ssp.hallii, C. parryana ssp.idahoa, andC. norvegica ssp.stevenii.     

Potential consequences of climate warming for tropical plant species in high mountains of southern Ethiopia

Aim Species in the tropics respond to global warming by altitudinal distribution shifts. Consequences for biodiversity may be severe, resulting in lowland attrition, range‐shift gaps, range contractions and extinction risks. We aim to identify plant groups (growth forms, families, endemic status) with higher than average risks. Location South Ethiopian highlands. Methods Based on observational data from mainly unexplored and remote mountain regions, we applied a published model to project the consequences of an upward shift of thermal site conditions on the altitudinal distribution of 475 plant species. Annual average temperature increases of up to 5 °C were evaluated. Differences between groups of species were analysed by a permutation procedure and Generalized Linear Models. Results Because of a limited regional species pool, even mild warming is projected to create strong potential risks concerning lowland attrition, i.e. the net loss of species richness because of upward range shifts in the absence of new species arriving. Likewise, many species are expected to face range‐shift gaps, i.e. the absence of an overlap between future and current altitudinal ranges already under mild warming scenarios. Altitudinal contractions and mountain‐top extinctions will potentially become important when warming exceeds 3.5 °C. Mean area per species is projected to decline by 55% for the A2 emissions scenario (+4.2 °C until 2100) because of the physical shape of the mountains. Higher than average vulnerability is expected for endemic species as well as for herbs and ferns. Plant families that are especially threatened are identified. Main conclusions Lowland biotic attrition and range‐shift gaps as predicted by a simple model driven by shifts of isotherms will result in novel challenges for preserving mountain biodiversity in the inner tropics. Whereas contractions of occupied area are expected to threaten endemic and already endangered species in particular, we suggest that conservation priorities can be identified based on simple prognostic models even without precise regional warming scenarios.     

Impacts of snow cover duration on vegetation spring phenology over the Tibetan Plateau

Aims Snow cover occupies large percentage of land surface in Tibetan Plateau. Snow cover duration (SCD) during non-growing seasons plays a critical role in regulating alpine vegetation’s phenology by affecting the energy budgets of land surface and soil moisture conditions. Different period’s snow cover during non-growing season may have distinct effect on the vegetation’s phenology. Start of season (SOS) has been observed advanced under the ongoing climate change in the plateau, but it still remains unclear how the SCD alters the SOS. This study attempts to answer the following questions: (i) What is the pattern of spatial and temporal variations for SCD and grassland SOS? (ii) Which period’s SCD plays a critical role in grassland’s SOS?     

Effects of physiological state on duration of sedation in southern elephant seals

One hundred eighty-one female and thirteen postweanling pup southern elephant seals (Mirounga leonina) were sedated using a combination of ketamine hydrochloride and xylazine hydrochloride. Physiological state had a profound effect on response of the animals to sedation. Physiologically stressed postlactation and postpartum cows had significantly longer periods of sedation than pre-molting females or recently weaned pups. Induction time was not affected by physiological status. Dose rates are recommended for elephant seals in various physiological states.     

Statolith shape and microstructure as indicators of ontogenetic shifts in the squid Gonatus fabricii (Oegopsida, Gonatidae) from the Norwegian Sea

Statolith shape and microstructure were studied in 151 specimens of the common arctic squid Gonatus fabricii (7.3–322 mm pen length) collected in the southern Norwegian Sea. Statolith development and growth both comprised two main periods, which corresponded with the epipelagic and meso-bathypelagic ontogenetic periods of G. fabricii. During the epipelagic period (pen length range from 3 to 50–60 mm), statoliths quickly developed from the droplet-like form in early paralarvae to the pre-definite stage in juveniles (30–50 mm pen length). Paralarval and juvenile statoliths grew with high growth rates, and their microstructure contained narrow first-order growth increments. Three main growth zones (Z1, Z2, Z3) developed during this period, being well distinguished from each other by specific patterns of microstructure and separated from each other by distinct checks. During the meso-bathypelagic period (from 50–60 to 322 mm pen length), statoliths hardly changed their shape and grew very slowly. Only one growth zone (Z4) was formed within the statolith microstructure, characterized by disappearance of the first growth increments and formation of specific second-order bands. Each second-order band consisted of approximately seven first-order increments. If the assumption “one increment-one day” is true for G. fabricii, the squid would then be a slow-growing animal with a life span for both sexes not exceeding 2 years. Accepted: 25 May 1999