Is bird incidence in Atlantic forest fragments influenced by landscape patterns at multiple scales?

The degree to which habitat fragmentation affects bird incidence is species specific and may depend on varying spatial scales. Selecting the correct scale of measurement is essential to appropriately assess the effects of habitat fragmentation on bird occurrence. Our objective was to determine which spatial scale of landscape measurement best describes the incidence of three bird species (Pyriglena leucoptera, Xiphorhynchus fuscus and Chiroxiphia caudata) in the fragmented Brazilian Atlantic forest and test if multi-scalar models perform better than single-scalar ones. Bird incidence was assessed in 80 forest fragments. The surrounding landscape structure was described with four indices measured at four spatial scales (400-, 600-, 800- and 1,000-m buffers around the sample points). The explanatory power of each scale in predicting bird incidence was assessed using logistic regression, bootstrapped with 1,000 repetitions. The best results varied between species (1,000-m radius for P. leucoptera; 800-m for X. fuscus and 600-m for C. caudata), probably due to their distinct feeding habits and foraging strategies. Multi-scale models always resulted in better predictions than single-scale models, suggesting that different aspects of the landscape structure are related to different ecological processes influencing bird incidence. In particular, our results suggest that local extinction and (re)colonisation processes might simultaneously act at different scales. Thus, single-scale models may not be good enough to properly describe complex pattern-process relationships. Selecting variables at multiple ecologically relevant scales is a reasonable procedure to optimise the accuracy of species incidence models.

Little evidence that condition, stress indicators, sex ratio, or homozygosity are related to landscape or habitat attributes in declining woodland birds

Habitat loss, fragmentation and degradation are drivers of major declines in biodiversity and species extinctions. The actual causes of species population declines following habitat change are more difficult to discern and there is typically high covariation among the measures used to infer the causes of decline. The causes of decline may act directly on individual fitness and survival, or through disruption of population processes. We examined the relationships among configuration, extent and status of native vegetation and three commonly used indicators of individual body condition and chronic stress (haemoglobin level, haematocrit, residual body mass condition index) in 13 species of woodland-dependent birds in south-eastern Australia. We also examined two measures of changes to population processes (sex ratio and individual homozygosity) in ten species and alleic richness in five species. We found little support for relationships between site or landscape characteristics and individual or population response variables, notwithstanding that our simulations showed we had sufficient power to detect relatively small effects. We discuss possible causes of the absence of detectable habitat effects in this system and the implications for the usefulness of individual body condition and easily measured haematological indices as indicators of the response of avian populations to habitat change. © 2012 The Authors.

Hydrologic landscape regionalisation using deductive classification and random forests

Landscape classification and hydrological regionalisation studies are being increasingly used in ecohydrology to aid in the management and research of aquatic resources. We present a methodology for classifying hydrologic landscapes based on spatial environmental variables by employing non-parametric statistics and hybrid image classification. Our approach differed from previous classifications which have required the use of an a priori spatial unit (e.g. a catchment) which necessarily results in the loss of variability that is known to exist within those units. The use of a simple statistical approach to identify an appropriate number of classes eliminated the need for large amounts of post-hoc testing with different number of groups, or the selection and justification of an arbitrary number. Using statistical clustering, we identified 23 distinct groups within our training dataset. The use of a hybrid classification employing random forests extended this statistical clustering to an area of approximately 228,000 km2 of south-eastern Australia without the need to rely on catchments, landscape units or stream sections. This extension resulted in a highly accurate regionalisation at both 30-m and 2.5-km resolution, and a less-accurate 10-km classification that would be more appropriate for use at a continental scale. A smaller case study, of an area covering 27,000 km2, demonstrated that the method preserved the intra- and inter-catchment variability that is known to exist in local hydrology, based on previous research. Preliminary analysis linking the regionalisation to streamflow indices is promising suggesting that the method could be used to predict streamflow behaviour in ungauged catchments. Our work therefore simplifies current classification frameworks that are becoming more popular in ecohydrology, while better retaining small-scale variability in hydrology, thus enabling future attempts to explain and visualise broad-scale hydrologic trends at the scale of catchments and continents.

A landscape-scale, applied fire management experiment promotes recovery of a population of the threatened Gouldian Finch, Erythrura gouldiae, in Australia's tropical savannas

Fire is an integral part of savanna ecology and changes in fire patterns are linked to biodiversity loss in savannas worldwide. In Australia, changed fire regimes are implicated in the contemporary declines of small mammals, riparian species, obligate-seeding plants and grass seed-eating birds. Translating this knowledge into management to recover threatened species has proved elusive. We report here on a landscape-scale experiment carried out by the Australian Wildlife Conservancy (AWC) on Mornington Wildlife Sanctuary in northwest Australia. The experiment was designed to understand the response of a key savanna bird guild to fire, and to use that information to manage fire with the aim of recovering a threatened species population. We compared condition indices among three seed-eating bird species-one endangered (Gouldian finch) and two non-threatened (long-tailed finch and double-barred finch)-from two large areas (> 2,830 km2) with initial contrasting fire regimes ('extreme': frequent, extensive, intense fire; versus 'benign': less frequent, smaller, lower intensity fires). Populations of all three species living with the extreme fire regime had condition indices that differed from their counterparts living with the benign fire regime, including higher haematocrit levels in some seasons (suggesting higher levels of activity required to find food), different seasonal haematocrit profiles, higher fat scores in the early wet season (suggesting greater food uncertainty), and then lower muscle scores later in the wet season (suggesting prolonged food deprivation). Gouldian finches also showed seasonally increasing stress hormone concentrations with the extreme fire regime. Cumulatively, these patterns indicated greater nutritional stress over many months for seed-eating birds exposed to extreme fire regimes. We tested these relationships by monitoring finch condition over the following years, as AWC implemented fire management to produce the 'benign' fire regime throughout the property. The condition indices of finch populations originally living with the extreme fire regime shifted to resemble those of their counterparts living with the benign fire regime. This research supports the hypothesis that fire regimes affect food resources for savanna seed-eating birds, with this impact mediated through a range of grass species utilised by the birds over different seasons, and that fire management can effectively moderate that impact. This work provides a rare example of applied research supporting the recovery of a population of a threatened species.

Responses of aquatic insect functional diversity to landscape changes in Atlantic forest

The Atlantic Forest domain, one of the 25 world's hotspots for biodiversity, has experienced dramatic changes in its landscape. While the loss of species diversity is well documented, functional diversity has not received the same amount of attention. In this study, we evaluated functional diversity of insects in streams utilizing three indices: functional diversity (FD), functional dispersion (FDis), and functional divergence (FDiv), seeking to understand the roles of three predictor sets in explaining functional patterns: (1) bioclimatic and landscape variables; (2) spatial variables; and (3) local environmental variables. We determined the amount of variation in different measures of functional diversity that was explained by each predictor set and their interplays using variation partitioning. Our study showed that variation in functional diversity is better explained by a set of variables linked to different scales dependent on spatial structures, indicating the importance of landscape and mainly environmental variables in the functional organization of aquatic insect communities, and that the relative importance of predictor sets depends on the indices considered. Variation in FD was better explained by the interplay among the three predictor sets and by local environmental variables, whereas variation in FDis was better explained by spatial variables and by the interplay between environmental and spatial variables. Variation in FDiv was not significantly explained by any predictors. Our study adds more evidence on the harmful effects caused by landscape changes on biodiversity in the Atlantic Forest, suggesting that these effects also influence the functional organization of stream insect communities. © 2013 The Author(s) Journal compilation © 2013 by The Association for Tropical Biology and Conservation.

Functional and phylogenetic diversity of scattered trees in an agricultural landscape: Implications for conservation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D-1), Simpson's dominance (D-2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P.lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.

Landscape properties mediate the homogenization of bird assemblages during climatic extremes

Extreme weather events, such as drought, have marked impacts on biotic communities. In many regions, a predicted increase in occurrence of such events will be imposed on landscapes already heavily modified by human land use. There is an urgency, therefore, to understand the way in which the effects of such events may be exacerbated, or moderated, by different patterns of landscape change. We used empirical data on woodlanddependent birds in southeast Australia, collected during and after a severe drought, to document temporal change in the composition of bird assemblages in 24 landscapes (each 100 km2) representing a gradient in the cover of native wooded vegetation (from 60% to <2%). We examined (a) whether drought caused region-wide homogenization of the composition of landscape bird assemblages, and (b) whether landscape properties influenced the way assemblages changed in response to drought. To quantify change, we used pairwise indices of assemblage dissimilarity, partitioned into components that represented change in the richness of assemblages and change in the identity of constituent species (turnover). There was widespread loss of woodland birds in response to drought, with only partial recovery following drought-breaking rains. Region-wide, the composition of landscape assemblages became more different over time, primarily caused by turnover-related differentiation. The response of bird assemblages to drought varied between landscapes and was strongly associated with landscape properties. The extent of wooded vegetation had the greatest influence on assemblage change: landscapes with more native vegetation had more stable bird assemblages over time. However, for the component processes of richness- and turnoverrelated compositional change, measures of landscape productivity had a stronger effect. For example, landscapes with more riparian vegetation maintained more stable assemblages in terms of richness. These results emphasize the importance of the total extent of native vegetation, both overall cover and that occurring in productive parts of the landscape, for maintaining bird communities whose composition is resistant to severe drought. While extreme climatic events cannot be prevented, their effects can be ameliorated by managing the pattern of native vegetation in anthropogenic landscapes, with associated benefits for maintaining ecological processes and human well-being.

The impact of abandoned/disused marble quarries on avifauna in the anticline of Estremoz, Portugal: does quarrying add to landscape biodiversity?

Although the extractive operations of quarrying are often considered environmental threats, there is some evidence that abandoned quarries may have a significant positive impact on biodiversity by enhancing habitat quality for several species. In Estremoz Anticlinal, SE Portugal, many of the existing marble quarries have been inactive for decades and were abandoned without any restoration project in progress. The impact of quarry abandonment on avifauna diversity was assessed relative to reference conditions using adjacent rural fields as control areas. No significant differences were found in within-community diversity (alpha diversity) between abandoned quarries and reference sites. However, several dissimilarity indices showed a clear divergence in species composition between abandoned quarries and reference sites. Furthermore, statistically significant differences in species compositions were found between quarries abandoned for different periods. Over time, species composition becomes more similar to that observed in reference sites, reflecting ecological succession and landscape resilience to quarrying. Nevertheless, the studied quarrying landscape exhibited higher gamma and beta diversity than the former traditional landscape; thus, our results suggest that abandoned quarries, rather than damaging and destroying niches, can promote new ecological niches and significantly diversify rural landscapes.

The impact of abandoned/disused marble quarries on avifauna in the anticline of Estremoz, Portugal: does quarrying add to landscape biodiversity?

Although the extractive operations of quarrying are often considered environmental threats, there is some evidence that abandoned quarries may have a significant positive impact on biodiversity by enhancing habitat quality for several species. In Estremoz Anticlinal, SE Portugal, many of the existing marble quarries have been inactive for decades and were abandoned without any restoration project in progress. The impact of quarry abandonment on avifauna diversity was assessed relative to reference conditions using adjacent rural fields as control areas. No significant differences were found in within-community diversity (alpha diversity) between abandoned quarries and reference sites. However, several dissimilarity indices showed a clear divergence in species composition between abandoned quarries and reference sites. Furthermore, statistically significant differences in species compositions were found between quarries abandoned for different periods. Over time, species composition becomes more similar to that observed in reference sites, reflecting ecological succession and landscape resilience to quarrying. Nevertheless, the studied quarrying landscape exhibited higher gamma and beta diversity than the former traditional landscape; thus, our results suggest that abandoned quarries, rather than damaging and destroying niches, can promote new ecological niches and significantly diversify rural landscapes.

Capturing Australian indigenous perception of virtual landscape

This short paper presents a means of capturing non spatial information (specifically understanding of places) for use in a Virtual Heritage application. This research is part of the Digital Songlines Project which is developing protocols, methodologies and a toolkit to facilitate the collection and sharing of Indigenous cultural heritage knowledge, using virtual reality. Within the context of this project most of the cultural activities relate to celebrating life and to the Australian Aboriginal people, land is the heart of life. Australian Indigenous art, stories, dances, songs and rituals celebrate country as its focus or basis. To the Aboriginal people the term “Country” means a lot more than a place or a nation, rather “Country” is a living entity with a past a present and a future; they talk about it in the same way as they talk about their mother. The landscape is seen to have a spiritual connection in a view seldom understood by non-indigenous persons; this paper introduces an attempt to understand such empathy and relationship and to reproduce it in a virtual environment.

Landscape symphonies : gardening as a source of landscape architecture practice engaged with change

The notion of designing with change constitutes a fundamental and foundational theoretical premise for much of what constitutes landscape architecture, notably through engagement with ecology, particularly since the work of Ian McHarg in the 1960s and his key text Design with Nature. However, while most if not all texts in landscape architecture would cite this engagement of change theoretically, few go any further than citation, and when they do their methods seem fixated on utilising empirical, quantitative scientific tools for doing so, rather than the tools of design, in an architectural sense, as implied by the name of the discipline, landscape architecture.