Woodland Vegetation Research Articles

Assessing the sensitivity of MODIS to monitor drought in high biomass ecosystems

Drought monitoring is important to analyse the influence of rainfall deficiency patterns on bushfire behaviour. Remote sensing provides tools for spatially explicit monitoring of drought across large areas. The objective of this study was to assess the performance of MODIS-based reflectance spectral indices to monitor drought across forest and woodland vegetation types in the fire prone Sydney Basin Bioregion, NSW, Australia. A time series of eight spectral indices were created from 2000 to 2009 to monitor inter-annual changes in drought and were compared to the Standardized Precipitation Index (SPI), a precipitation deficit/surplus indicator. A pixel-to-weather station paired correlation approach was used to assess the relationship between SPI and the MODIS-based spectral indices at different time scales. Results show that the Normalised Difference Infrared Index—band 6 (NDIIb6) provided the most suitable indicator of drought for the high biomass vegetation types considered. The NDIIb6 had the highest sensitivity to drought intensity and was highly correlated with SPI at all time scales analysed (i.e., 1, 3 and 6-month SPI) suggesting that variations in precipitation patterns have a stronger influence on vegetation water content than vegetation greenness properties. Spatial similarities were also found between patterns of NDIIb6-based drought maps and SPI values distribution. NDIIb6 outperformed the spectral index currently in use for operational drought monitoring systems in the region (Normalised Difference Vegetation Index, NDVI) and its implementation in existing drought-monitoring systems is recommended.

First Record ofFusarium verticillioidesas an Entomopathogenic Fungus of Grasshoppers

Fusarium verticillioides (Saccardo) Nirenberg (Ascomycota: Hypocreales) is the most common fungus reported on infected corn kernels and vegetative tissues, but has not yet been documented as being entomopathogenic for grasshoppers. Grasshoppers and locusts represent a large group of insects that cause economic damage to forage and crops. Tropidacris collaris (Stoll) (Orthoptera: Acridoidea: Romaleidae) is a large and voracious grasshopper that in recent years has become an increasingly recurrent and widespread pest in progressively more greatly extended areas of some of in Argentina's northern provinces, with chemical insecticides being currently the only means of control. During February and March of 2008–09, nymphs and adults of T. collaris were collected with sweep nets in dense woodland vegetation at a site near Tres Estacas in western Chaco Province, Argentina, and kept in screened cages. F. verticillioides was isolated from insects that died within 10 days and was cultured in PGA medium. Pathogenicity tests were conducted and positive results recorded. Using traditional and molecular-biological methods, an isolate of F. verticillioides was obtained from T. collaris, and its pathogenecity in the laboratory was shown against another harmful grasshopper, Ronderosia bergi (Stål) (Acridoidea: Acrididae: Melanoplinae). The mortality caused by F. verticillioides on R. bergi reached 58 ± 6.53% by 10 days after inoculation. This is the first record of natural infection caused by F. verticillioides in grasshoppers.

Integrating revegetation with management methods to rehabilitate coastal vegetation invaded by Bitou bush (Chrysanthemoides monilifera ssp. rotundata) in Australia

AbstractTwo multi‐year field experiments investigated the effects of integrating revegetation with invasive plant management methods to rehabilitate coastal dune and woodland vegetation invaded by Bitou bush (Chrysanthemoides monilifera (L.) Norl. ssp. rotundata (DC.) Norl.) in New South Wales, Australia. The revegetation technique used was to sow directly seeds of three native species common to coastal habitats. Management treatments involved combinations of prescribed fire, manual removal of Bitou bush and an application of herbicide. Addition of native seeds significantly increased density of native species in both habitats. The benefits of manually removing Bitou bush were observed only where densities of native species were at their lowest. Fire increased densities of some native species in the woodland, but decreased those of others in the dune. Densities of Acacia longifolia ssp. sophorae (Labill.) Court (woodland) and of Banksia integrifolia L.f. (woodland and dune) were significantly reduced within 4 months of herbicide application, alone or in combination with other treatments. The majority of these effects, however, did not persist. Manual removal in both habitats and addition of seed in the woodland were most effective in reducing Bitou bush densities when applied post‐fire. Herbicide treatment on its own or in combination with other treatments did not significantly reduce Bitou bush densities by the end of the experiments. We conclude that restoration of coastal ecosystems invaded by a major invasive plant species requires a whole‐of‐system approach involving revegetation in combination with known management methods to assist recovery of native species in the longer term.

Sterols in soil organic matter in relation to nitrogen mineralization in sandy arable soils

AbstractUnusually low net N mineralization in soils relatively rich in total organic C and N was repeatedly reported for sandy arable soils in NW Europe. In order to adequately account for it in simulation models, it is necessary to know the involved substances and processes. Therefore, 9 arable top soils (< 6% clay) with a wide range of total organic C (1.1%–5.2%) and C : N ratios (12–35) were studied. The soils varied strongly in the mineralizability of soil organic N which was determined via long‐term laboratory incubations (> 200 d). It was hypothesized that mineralization was controlled by antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) of the soils was measured. In addition, pyrolysis–field ionization mass spectrometry (Py‐FIMS) was applied to investigate the influence of the molecular‐chemical composition of soil organic matter. In these soils, the compound class of sterols from Py‐FIMS analysis was most closely, negatively correlated with the mineralizability of soil organic N (r<?h.3>2 = 0.75, p = 0.003). This was probably not an antioxidative effect, because the TEAC values did not correlate sufficiently with the mineralizability and the sterol intensities. However, the negative relation with sterols could be causal, since the correlation was about as close with other components of the compound class of sterols and even closer with the main plant sterol beta‐sitosterol (r<?h.3>2 = 0.84, p = 0.001). In addition, the variability among samples was strongly governed by the proportions of sterols, and sterols also had a high discriminating power in discriminant analysis. Furthermore, the proportions of sterols were extraordinary in those arable podzol soils that developed under previous heath‐ or woodland (up to 10.2% of total ion intensity from Py‐FIMS). In conclusion, the inhibitory effect of these compounds needs to be investigated in more detail in order to optimize parameterization of N as well as C simulation models especially for podzolized, sandy arable soils with former heath‐ or woodland vegetation.

Comparative gas exchange performance during the wet season of three Brazilian Styrax species under habitat conditions of cerrado vegetation types differing in soil water availability and crown density

We studied the influence of environmental conditions in different vegetation types of the Brazilian savanna (cerrado s.l.) on CO 2 assimilation and water use efficiency of Styrax ferrugineus, S. camporum and S. pohlii, which are morphologically similar but have distinct distribution patterns. We measured leaf gas exchange and water relations in adult and young plants. Adult plants of S. ferrugineus were measured in the cerrado s. str.; plants of S. camporum at the edge of cerradão, a woodland vegetation; and in a riparian forest those of S. pohlii. Eight-month-old young plants were planted in the cerrado s. str., at the edge and in the understory of the cerradão, and in the understory of the riparian forest. For young plants, the high light availability in the cerrado s. str. resulted in a threefold greater CO 2 assimilation rate ( A) compared to the other sites. A of adult plants under full irradiation (1800 μmol photons m −2 s −1) was significantly lower in S. pohlii compared to S. ferrugineus and S. camporum. Although sufficient soil water was available at every site at the end of the wet season, the extreme high water content in the riparian forest soil led to increased stomatal conductance ( gs) and transpiration rate ( E) for young plants of S. camporum and S. pohlii, but not of S. ferrugineus. However, the large gs in S. pohlii and S. camporum young plants did not result in higher A rates. The differences may indicate some specialization of S. ferrugineus to best growth in open savanna and of S. pohlii in riparian forest habitats. The high water use efficiency of S. camporum young plants in the understory of cerradão seems not yet sufficient to emphasize that this species benefits from this particular habitat. Because, while water supply during the wet season is quite sufficient, soil water deficits and frequent fires can occur during the dry season and might modify strongly the habitat conditions for the three Styrax species.

State-and-transition modelling for Adaptive Management of native woodlands

Adaptive Management (AM) is widely advocated as an approach to dealing with uncertainty in natural resource management as it provides an explicit framework for motivating, designing and interpreting the results of monitoring. One of the major factors impeding implementation is the failure to use appropriate process models; a core element of AM. Process models represent beliefs about the properties and dynamics of an ecological system and ecosystem responses to management. Quantitative models of ecosystem response help resolve ambiguity about the efficacy of management and facilitate iterative updating of knowledge using monitoring data. We report on the use of a state-and-transition model (STM) in the Adaptive Management of native woodland vegetation in south-eastern Australia. The STM is implemented as a Bayesian network, making it simple to communicate and update with new data as they arise. Application of the model is demonstrated using case-study and simulation data. We show how the model may be used to predict the probability of achieving desirable state transitions at restoration sites and how monitoring of those sites can be used to update the model (learn) and adapt (review restoration strategies). After just one monitoring/learning cycle, 7 years after the first investments, we found that updated models predict markedly different transition probabilities compared with initial models based on expert opinion. This has strong implications for the apparent cost-efficiency of restoration strategies. The STM approach provides a sound theoretical basis for restoration decisions, while the Bayesian network implementation provides a workable framework for using the STM adaptively.

Floristic and structural analysis of the woodland vegetation around Dello Menna, southeast Ethiopia

Floristic composition and vegetation structure were described for the woodland vegetation around Dello Menna, Bale zone, southeast Ethiopia. A total 50 (20 m × 20 m) quadrats were sampled to identify and describe plant community types, species diversity, richness and evenness and to relate the identified plant community types with some environmental factors and describe the population structure of woody plant species. In each quadrat, data on species identity, abundance, height and Diameter at Breast Height (DBH) of woody plant species, altitude and slope were recorded. Vegetation classification was performed using PC — ORD software package. Sorensen’s similarity coefficient was used to detect dissimilarities among communities. Shannon — Wiener diversity index, species richness and Shannon’s evenness were computed to describe species diversity of the plant community types. Results show that a total of 171 vascular plant species representing 53 families were recorded. Fabaceae is the dominant family represented by 13 genera and 26 species (15%) followed by Asteraceae, Lamiaceae and Anacardiaceae with eight species each (4.6%). Based on the results of vegetation classification, three plant communities (Dalbergia microphylla community, Grewia bicolar- Acacia brevispica community, and Combretum molle-Combretum collinum community) are recognized and described. Species richness, diversity and evenness varied among the plant communities. Species richness and diversity exhibit a bell — shaped pattern along altitude. Species turn over among communities more or less follow altitudinal gradients. Tukey’s pairwise comparison of means among the plant community types shows significant variations in altitude, implying that altitude is one of the most important factors determining the distribution of plant communities. The community Dalbergia microphylla type exhibits the highest species richness and diversity. Analysis of population structure of the dominant species reveals various patterns. Future research directions and recommendations are suggested for the sustainable utilization of the vegetation.

Ecohydrological energy inputs in semiarid coniferous gradients: Responses to management- and drought-induced tree reductions

Large-scale, rapid reductions in forest and woodland tree cover caused by fire, drought-induced die-off, or wildfire-mitigating thinning prescriptions, all three of which differentially affect canopy structure, are increasingly altering coniferous-dominated landscapes across extensive regions such as western USA. These types of reductions in canopy cover can result in substantial increases in near-ground solar radiation, which in turn drive numerous ecological processes. However, existing relationships for how reductions in canopy cover translate into changes in incoming near-ground solar radiation do not account for the ways in which fire, die-off, and thinning differentially alter either or both the foliar and woody components of canopy architecture and the degree to which such alterations depend on foliar density. We systematically quantified trends in near-ground solar radiation for a broad range of canopy cover for two of the most extensive semiarid coniferous forest and woodland vegetation types in the western USA: those dominated by a combination of piñon and juniper (using Pinus edulis and Juniperus monosperma as representative species) or by ponderosa pine (Pinus ponderosa). We used hemispherical photography to account for how canopy architecture affected mean and variance in near-ground solar radiation over a broad range of canopy cover (from as low as ∼5% to as high as ∼85%). For both vegetation types, we evaluated four disturbance types: undisturbed, controlled burns, drought- and beetle-induced die-off, and prescriptive thinning treatments. We also assessed near-ground solar radiation for undisturbed vegetation spanning an elevation continuum that included both piñon-juniper and ponderosa pine vegetation types. Our results quantify how near-ground solar radiation varies substantially and systematically among forest gradient types and as a function of forest disturbance type. Trends in near-ground solar radiation differed among gradients associated with fire, die-off, or thinning, dependent on how each affects the foliar and/or woody components of canopy architecture. Deviations from undisturbed conditions for remaining disturbed tree cover were greatest for burned, intermediate for die-off and least for thinned. The differences in microclimate quantified here and how they vary with type of tree reduction are relevant for assessing vegetation responses following reductions in tree cover. In addition, the differences are large enough to require consideration in evaluating land surface interactions of forests and woodlands with the atmosphere (e.g., increases of >40Wm−2 relative to undisturbed conditions). Our results provide a means to enable managers to rapidly relate readily-obtainable field estimates of canopy cover to approximate estimates of near-ground solar radiation.

Vegetation and landscape connectivity control wildfire intervals in unmanaged semi-arid shrublands and woodlands in Australia

Aim The aim of this study was to determine how spatial variation in vegetation type and landscape connectivity influence fire intervals in a semi-arid landscape with low relief and complex mosaics of woodland and shrubland vegetation. Location Our study focused on a 15,500-km2 area of relatively undisturbed and unmanaged land in south-western Australia, referred to as the Lake Johnston region. Methods We modelled fire-interval data from a 67-year (1940–2006) digital fire history database using a two-parameter Weibull function, and tested for the effects of vegetation type and landscape connectivity on estimates of the length of fire intervals (Weibull parameter b) and the dependence of fire intervals on fuel age (Weibull parameter c). Results Vegetation type and landscape connectivity significantly influenced fire interval probability distributions. Fire intervals in shrublands (dense low shrub assemblage) were typically shorter (b = 46 years) and more dependent on fuel age (c = 2.33) than most other vegetation types, while fire intervals in open eucalypt woodlands were much longer (b = 405 years) and were less dependent on fuel age (c = 1.36) than in shrub-dominated vegetation types. Areas adjacent to or surrounded by salt lakes burnt less frequently (b = 319 years) and fire intervals were less dependent on fuel age (c = 1.48) compared with more exposed areas (e.g. b < 101 years, c > 1.68). Fire intervals in thickets (dense tall shrub assemblage) were longer (b = 101 years) than would be expected from fuel loads, most likely because they were protected from fire by surrounding fuel-limited woodlands. Main conclusions Fire intervals in south-western Australia are strongly influenced by spatial variation in vegetation (fuel structure) and landscape connectivity. The importance of fuel structure as a control of fire intervals in south-western Australia contrasts with other landscapes, where topographical gradients or climatic influences may override the effects of underlying vegetation. We found that, regardless of low relief, topographical features such as large salt lake systems limited the connectivity and spread of fire among landscape units in an analogous manner to lakes or mountainous features elsewhere.

The effects of urban or rural landscape context and distance from the edge on native woodland plant communities

The increasing rate of urban sprawl continues to fragment European landscapes threatening the persistence of native woodland plant communities. The dynamics of woodland edges depend on the characteristics of woodland patches and also on landscape context. Our aim was to assess the extent of edge influences on the understorey vegetation of small native woodlands in rural and urban landscapes. The study was carried out in two cities of north-western France. Ten comparable woodlands, each of about 1.5 ha, were surveyed; five were situated adjacent to crops and five adjacent to built-up land. Vascular plant species were recorded in 420 3 × 3 m plots placed at seven different distances from the edge (from 0 to about 45 m from the edge). Soil pH, light levels, level of disturbance and tree and shrub cover were also recorded. Plant species were first classified as non-indigenous or indigenous and then three groups of indigenous species were distinguished according to their affinity for forest habitat (forest specialists, forest generalists and non-forest species). We inferred certain ecological characteristics of understorey vegetation by using Ellenberg values. An inter-class correspondence analysis was carried out to detect patterns of variation in plant community composition. Linear mixed models were used to test the effects of adjacent land use, distance from the edge and their interactions on the species richness of the different groups and on the ecological characteristics of vegetation. Total species richness, richness of forest generalists and of non-forest species decreased from edge to interior in both urban and rural woodlands. The number of non-indigenous species depended mainly on urban–rural landscape context. Urban woodland edges were not as rich in forest specialists as rural edges. More surprisingly, the number of forest specialists was higher in rural edges than in rural interiors. Community composition was mainly affected by urban–rural context and to a lesser degree by the edge effect: the community composition of urban edges resembled that of urban interiors whereas in rural woodlands vegetation near edges (up to 10 m) strongly differed from interiors with a pool of species specific to edges. Urban woodland vegetation was more nitrophilous than rural vegetation in both edges and interiors. A major difference between urban and rural vegetation was the distribution of basiphilous species according to distance from the edge. Generally edge vegetation was more basiphilous than interior vegetation however the presence of basiphilous species fell off quickly with distance from the edge in rural woodlands (in the first 10–15 m) and more slowly (from 25 m onwards) in urban woodlands. This pattern was linked to variation in measured soil pH. As regards the conservation of flora in small native woodlands, it appeared that invasion of exotic and non-forest species was currently limited in both urban and rural landscape contexts but might pose problems in the future, especially in urban woodlands. Forest species were not negatively affected by the edge effect and indeed edges seemed to provide important habitats for this group. Hence conservationists should pay particular attention to the protection of edges in urban woodlands.

Evaluating the adequacy of reserves in the Tembe–Tshanini Complex: a case study in Maputaland, South Africa

AbstractThe aim of this study was to determine the minimum conservation area needed to conserve vegetation types and their landscape and to apply it to an area in KwaZulu-Natal, South Africa, which is within the Maputaland Centre of Plant Endemism and part of the Maputaland–Pondoland–Albany biodiversity hotspot. Outside conservation areas this Centre of Plant Endemism is under threat from human utilization. We used a method initially designed to determine minimum conservation areas for rare plant species, which we adapted from its original country and context, to determine minimum conservation areas for landscape species in Maputaland’s little-documented environment. The minimum area required for conservation was established for the Sand Forest and Woodland vegetation types in the region. We found that sufficient habitat is presently conserved to preserve the Sand Forest but not the Woodlands. The method holds promise to provide answers to critical conservation issues in lesser-known environments and, although relatively difficult to establish for the first time, is an efficient and easy to use tool that can be refined once more knowledge becomes available.

Integration by case, place and process: transdisciplinary research for sustainable grazing in the Lachlan River catchment, Australia

In a context of global agricultural intensification, integrating conservation and agricultural production is a major challenge. We have tackled the problem using a transdisciplinary research framework. Our work focuses on part of the upper Lachlan River catchment in southeastern Australia. The region is dominated by livestock grazing, and is part of an internationally recognised threatened ecoregion because most native woodland vegetation has been cleared. In productive areas, most remnant vegetation occurs as scattered and isolated paddock trees, which are dying from old age and not regenerating due to agricultural practices. The policy context and industry trends present additional risks for sparse trees. These declining trees provide many ecosystem services, including enhanced water infiltration, shade for livestock, aesthetic and cultural values, and habitat for native species. Our research aims to identify management options and policy settings that enable landscape-scale tree regeneration while maintaining grazing production. Our findings highlight tensions between the trajectory of tree cover in the region and stakeholder values. Under status quo management, many scattered and isolated paddock trees will be lost from farms, although most farmers would like to see them persist. Case studies on selected farms reveal management strategies that may be more sustainable in terms of tree regeneration and agricultural productivity, such as rotational grazing. In addition to these applied insights, our work provides a case study illustrating how a transdisciplinary study can be conducted efficiently by a small team. Our pragmatic approach has successfully combined targeted disciplinary activities with strategic collaborations and stakeholder engagement, all united by shared landscape, case graziers, and outreach activities.

Tree species composition, structure and utilisation in Maruzi Hills Forest Reserve in Uganda

The study investigated the tree species composition, vegetation structure and harvesting pattern to guide management of the Maruzi Hills Forest Reserve. Stratified random sampling was used to site six (100 m × 100 m) permanent sample plots in the woodland, bushland and grassland vegetation types identified in the reserve. Rényi diversity profiles indicated that bushland vegetation had a lower Shannon diversity index (H = 2.054) than grassland (H = 2.38) and woodland vegetation (H = 2.319). Grassland and woodland vegetation also had lower proportions of the dominant species (α∞ = 1.15 and 1.66, respectively) than bushland vegetation (α∞ = 3.25). However, the mean stem density of the woodland, bushland and grassland vegetation was 214 stems ha−1, 191 stems ha−1 and 114 stems ha−1, respectively. Bray-Curtis and Jaccard ecological distance matrices showed that, although the three vegetation types shared some common species, the ecological distances were relatively high suggesting significant species composition variation between the vegetation types, particularly between the bushland and the other vegetation types. The species with the highest proportional abundance in the survey were Combretum molle (23%), Acacia hockii (17.7%), Combretum collinum (16.1%), Grewia mollis (6.5%) and Lannea barteri (6.5%). Diameter size-class distribution of woody perennials and tree stumps indicated higher frequencies of the smaller-diameter size classes. The stump records were indicative of charcoal burning and firewood collection as major causes of tree/shrub harvesting. The Maruzi Hills woodland conservation strategy should consider the differences in species composition between vegetation types if the highest number of species is to be conserved.

Bird foraging height predicts bird species response to woody vegetation change

Accurate a priori predictions of the sensitivity of species to vegetation man- agement depend on an understanding of mechanisms underlying species response. To date information on where birds forage in the vegetation strata has been used to predict bird species response to vegetation change caused by livestock grazing. Profiting from this link between vegetation structural diversity and bird diversity, we test whether this variable, bird foraging height, can be used to predict the impact of a different type of habitat alteration; vegetation encroachment. Increases in vegetation density, called 'encroach- ment' or 'thickening', throughout savanna landscapes are considered a serious manage- ment issue for pastoral activities and a potential threat to biodiversity. We developed woody-vegetation-change models to predict the effect of vegetation encroachment on bird species through an understanding of where birds forage in intact vegetation communities. We compare model predictions with bird abundance data collected from 60 field sites representing a single woodland vegetation type, but with a gradient of woody vegetation density caused by clearing, thinning and natural climatic perturbation. Our model suc- cessfully predicted for the majority (80%) of birds considered, whether a species was likely to increase, decrease or remain unaffected by increases in woody vegetation density. We find that the majority of species respond positively to vegetation encroachment. Our approach avoids problems of post hoc data interpretation and tests a specific mechanism underlying bird species response to habitat alteration, bird foraging height. Simple pre- dictive models such as these will assist land managers make informed decisions about management actions and consequences, particularly in cases where decisions need to be made urgently and preclude the collection and analysis of primary ecological data sets.

Using photography to elicit grazier values and management practices relating to tree survival and recruitment

Abstract Integrating conservation and agricultural production is a major challenge globally. The upper Lachlan catchment of Australia is dominated by livestock grazing, and is threatened because most native woodland vegetation has been cleared. A third of all remaining tree cover occurs as scattered trees in grazing pastures. These scattered trees are dying from old age and are not regenerating due to grazing pressure. Previous work has revealed management strategies that are more likely to maintain tree cover, such as low-input rotational grazing. We asked graziers to photograph significant features on their properties, and used the images as prompts in later interviews. This elicited graziers’ landscape values and other drivers of their management practices related to tree cover. The targets that our 25 case landholders chose to photograph, and the ways they discussed them in later interviews, reflected the focus of past education and incentive programs, suggesting that well-designed policies, educational messages and incentives do seem to reach landholders and result in improved practices. For example, many landholders reported management activities related to the protection of large woodland patches or the maintenance of coarse woody debris. The maintenance of scattered tree cover has not been a focus of policy initiatives in the past. Despite this, the narratives elicited by photos of isolated and scattered trees showed graziers valued them and were aware of and concerned about their decline, yet lacked knowledge about how to protect and regenerate them. Graziers urgently need unambiguous advice and practical assistance to help them adapt their practices to maintain scattered trees in the long term.

Value of Semi‐Open Corridors for Simultaneously Connecting Open and Wooded Habitats: a Case Study with Ground Beetles

To counteract habitat fragmentation, the connectivity of a landscape should be enhanced. Corridors are thought to facilitate movement between disconnected patches of habitat, and linear strips of habitat connecting isolated patches are a popular type of corridor. On the other hand, the creation of new corridors can lead to fragmentation of the surrounding habitat. For example, heathland corridors connect patches of heathland and alternatively hedgerows connect patches of woodland. Nevertheless, these corridors themselves also break up previously connected patches of their surrounding habitat and in so doing fragment another type of habitat (heathland corridors fragment woodlands and woodland strips or hedgerows fragment heathlands). To overcome this challenge we propose the use of semi-open habitats (a mixture of heathland and woodland vegetation) as conservation corridors to enable dispersal of both stenotopic heathland and woodland species. We used two semi-open corridors with a mosaic of heathland and woody vegetation to investigate the efficiency of semi-open corridors for species dispersal and to assess whether these corridors might be a suitable approach for nature conservation. We conducted a mark-recapture study on three stenotopic flightless carabid beetles of heathlands and woodlands and took an inventory of all the carabid species in two semi-open corridors. Both methodological approaches showed simultaneous immigration of woodland and heathland species in the semi-open corridor. Detrended correspondence analysis showed a clear separation of the given habitats and affirmed that semi-open corridors are a good strategy for connecting woodlands and heathlands. The best means of creating and preserving semi-open corridors is probably through extensive grazing.

Evidence that a Highway Reduces Apparent Survival Rates of Squirrel Gliders

Roads and traffic are prominent components of most landscapes throughout the world, and their negative effects on the natural environment can extend for hundreds or thousands of meters beyond the road. These effects include mortality of wildlife due to collisions with vehicles, pollution of soil and air, modification of wildlife behavior in response to noise, creation of barriers to wildlife movement, and establishment of dispersal conduits for some plant and animal species. In southeast Australia, much of the remaining habitat for the squirrel glider, Petaurus norfolcensis, is located in narrow strips of Eucalyptus woodland that is adjacent to roads and streams, as well as in small patches of woodland vegetation that is farther from roads. We evaluated the effect of traffic volume on squirrel gliders by estimating apparent annual survival rates of adults along the Hume Freeway and nearby low-traffic-volume roads. We surveyed populations of squirrel gliders by trapping them over 2.5 years, and combined these data with prior information on apparent survival rates in populations located away from freeways to model the ratio of apparent annual survival rates in both site types. The apparent annual survival rate of adult squirrel gliders living along the Hume Freeway was estimated to be approximately 60% lower than for squirrel gliders living near local roads. The cause of the reduced apparent survival rate may be due to higher rates of mortality and/or higher emigration rates adjacent to the Hume Freeway compared with populations near smaller country roads. Management options for population persistence will be influenced by which of these factors is the primary cause of a reduced apparent survival rate. © 2010 by the author(s).

Effects of fire on tenebrionid communities of a Pinus pinea plantation: a case study in a Mediterranean site

Fire is a frequent event in Mediterranean ecosystems, yet the effects on animal diversity are poorly understood. In this paper, the short-term effects of a severe fire on the tenebrionid beetles in a planted pinewood in Central Italy are investigated in comparison with those recorded in other animal communities, namely collembolans, isopods and birds. The use of statistical tests to compare values of dominance, diversity and equitability (measured with various indexes), between burned and unburned habitats, as well as the use of two major niche-based species abundance models (the geometric series and the MacArthur broken stick model), revealed a strong decrease in diversity and evenness in all investigated animal groups, including birds, for which previous research suggested minor effects. In particular, tenebrionids are proved to be particularly indicative of habitat transformations determined by fire, showing important changes in community structure, from that characteristic of woodlands to that of open habitats. Because most of the original vegetation of Mediterranean woodlands has been removed by the continued influence of man, mature pinewoods, even if artificial, represent an important surrogate habitat for most species of tenebrionids (and likely other animals of conservation concern, such as bird species), and their preservation from catastrophic fires is of paramount importance.

Chimpanzee nest distribution and site reuse in a dry habitat: implications for early hominin ranging

This paper reports on a 20-month study of chimpanzee nesting patterns in Issa, Ugalla, western Tanzania. Ugalla is one of the driest, most open, and seasonal habitats where chimpanzees are found. The methods used were ethoarchaeological, as the chimpanzees were not habituated and behavioural observations were rare. Systematic data on the spatial and temporal distribution of nests are presented. Places with no nests at the beginning of the study, despite being suitable for nesting, were used as controls. Similar to other chimpanzee study sites, nests were highly concentrated in some parts of the landscape. Issa chimpanzees preferred to nest on slopes. They extensively used the woodland vegetation type of their habitat for nesting throughout the annual cycle. Ninety percent of nest sites were used repeatedly throughout the study period, but none of the control places had nests during this period. The results indicate that chimpanzees ranged more widely during the dry season, when food abundance was lowest, food was available mainly in open vegetation types, and when drinking water was restricted to a few sources. Early hominins in similar habitats may have followed the ranging strategy of Issa chimpanzees. As with a previous study, the distribution of nests was spatially similar to archaeological distributions in early hominin sites. Hominin topography and vegetation type preferences may be misrepresented in the archaeological record. Nest sites may have been the antecedents of carcass processing sites.

Patterns of plant biodiversity in the woodland-steppe ecotone in southeastern Inner Mongolia

Biodiversity patterns of the woodland-steppe ecotone in southeastern Inner Mongolia were investigated. Controlled by climatic factors, the plant species diversity of the woodland-steppe ecotone is moderate as compared with the adjacent woodland and steppe communities. From woodland through woodland-grassland and woodland-steppe to steppe, about 2/3 species were replaced at each boundary; only seven herb species were detected to be distributed in all four vegetation zones. Landscape classification based on landform, climate, and vegetation shows that landform condition is most critical to landscape diversity in the studied area. The most fragmented landform in the woodland zone does not necessarily lead to low plant species diversity. However, similar understory species in different woodland types lead to continuous woodland vegetation and, hence, high species richness. High fragmentation in the woodland-steppe zone and discontinuous distribution of woodlands might be a driving factor for lower species richness. Reconstruction of the Holocene climatic changes and vegetation development demonstrates that the highest plant species diversity occurred in the ecotone from 4500 to 2500 14C yr BP at different sites, while the woodland zone extended much farther northwestward. When woodlands retreated from the current ecotone with climatic drying, the fragmentation of woodlands in the current ecotone led to plant species loss.