Internal fragmentation: the effects of roads, highways and powerline clearings on movements and mortality of rainforest vertebrates

General Implications: 1. Linear environmental discontinuities such as roads and powerlines may fragment rainforest wildlife populations. Arboreal species and those of the rainforest understory and ground layer are most likely to be affected. 2. The mobility and behavioural characteristics of species, particularly those relating to open-space avoidance, largely determine the magnitude of the linear barrier effect. In contrast, species that do not avoid open space may be prone to road mortality or predation along roads. 3. As the width of the linear clearing increases, road-crossing attempts by many rainforest species rapidly decline. Eventually, clearings are likely to form a complete or almost complete barrier, apart from rare stochastic crossings. 4. In clearings wide enough to support grassy swaths, the presence of a distinctive grassland faunal community may compound structural and microclimatic differences to result in almost complete exclusion of rainforest species. 5. To mitigate fragmentation effects of rainforest roads and highways, the widths should be minimised, particularly near streams and gullies, where many species attempt to cross. 6. Canopy connectivity above a road should be maintained wherever possible to provide potential crossing points for arboreal species. In addition, the presence of some canopy cover produces a microclimate on the road surface that is somewhat similar to that of the adjacent rainforest, and provides some cover for understory species attempting to cross. 7. Underpasses and culverts form crossing routes for a number of rainforest mammals and other vertebrates. A range of sizes and designs of culverts may increase their utility as faunal crossing routes. 8. Allowing rainforest regrowth to develop along powerline clearings clearly helps to mitigate the barrier effects of these clearings for small mammals. 9. The effects of new powerlines can be reduced by clearing only tower footprints, and subsequently maintaining the powerline by helicopter. Alternatively, strips of forest can be retained in gullies along the powerline route. 10. When planning for new roads and powerlines, resource managers should strive to avoid critical habitats for rare or threatened species as well as areas of high biological diversity and abundance

Enhancing plant diversity in secondary forests

Dispersal, recruitment and establishment limitations are crucial processes shaping forest composition. In secondary forests these mechanisms may operate differently than in mature forests, because young and isolated secondary forests may suffer stronger limitations due to a lack of suitable dispersers and harsh environmental conditions— such as the elevated competition of exotic grasses. To assess establishment limitations in these forests, we undertook transplant experiments involving seeds and seedlings along a chronosequence of secondary forests in tropical Australia. The experiments included six species that varied in seed size (6–50 mm in length) and successional status (early to late successional). Seeds of five species were placed in one of three treatments: (1) exposed seeds, (2) fenced seeds, and (3) buried seeds, and multiple seedlings of six species were transplanted in block treatments. After 14–17 months, seed from all plant species germinated across all ages of secondary forests. However, in young secondary forest sites (4–12 years) fewer germinated seeds survived. The highest survival rates were observed for buried seeds (27.2%) compared to the low survival of exposed seeds (6.0%). Planted seedlings (6 spp) had the greatest overall survival (63.1%) and the highest growth rates in older secondary forests. We found that species identity was important for growth and survival in both experiments, but detected no effect of successional status or seed size. A crucial finding of this study was that the buried seeds of all species germinated and had relatively high survival irrespective of variation in site conditions or successional status, suggesting that seed availability may be a greater barrier to recovery of secondary forests in the region than the establishment limitations imposed by environmental conditions

Roads in Rainforest: best practice guidelines for planning, design and management

These Guidelines were developed as a framework for understanding the primary ecological issues to be addressed in the planning, design and management of roads in rainforest environments. This manual has been created to assist in reducing the main impacts of roads, which are primarily: • Habitat loss and fragmentation; • Reduction in habitat quality; • Edge effects; • Reduced animal movements, resulting in restricted genetic flows and diminished survival rates in some species; • Population reduction through road kill of wildlife species; • Erosion, sedimentation and pollution; • Impacts on scenic quality; • Disturbance from vehicular noise, headlights and movement; • Facilitation of the spread of exotic pests, • weeds and diseases; and • Direct mortality from road construction activities. Cumulatively, these impacts threaten the biodiversity and integrity of ecosystem processes throughout Queensland’s tropical forests. It is therefore imperative that current and future road infrastructure be designed with consideration of these factors within the context of the natural environment. This document provides a set of principles and supporting guidelines for implementing best practice planning, design and management for ecologically sustainable roads within rainforests throughout Queensland. The intention of these Guidelines is to describe the particular aspects of rainforest environments that are unique and thus require particular consideration when designing and constructing roads in these habitats. Therefore, these Guidelines were specifically developed to: • Inform planners, engineers and managers about the key ecological elements (Principles) to consider when building roads in rainforest environments; • Identify the most important issues to consider when planning, designing and implementing plans for road infrastructure so that the impacts to the primary ecological elements of rainforests are minimised. Each major issue is clarified within its own ‘Guideline’; and • Provide a set of steps and checklists within each Guideline to ensure that the core Principles are maintained throughout the different phases of planning, design and construction

Αξιολόγηση εξωτερικοτήτων εγκαταστάσεων βιοαερίου

Fusarium oxysporum f. sp. cubense tropical race 4 (TR4) is reported for the first time in northern Queensland, the centre of Australia’s commercial banana production. The identity of the pathogen was confirmed by vegetative compatibility group testing, TR4 specific PCR tests and sequencing. Although presently confined to a single property, the disease poses a serious threat to Australia’s banana industry

The effect of roads on spider monkeys' home range and mobility in a heterogeneous regenerating forest

Arboreal fauna living in tropical ecosystems may be particularly affected by roads given their dependency on forest cover and the high vulnerability of such ecosystems to changes. Over a period of 4 yr, we followed subgroups of spider monkeys living in a regenerating dry tropical forest with 8.2 km of roads within their home range. We aimed to understand whether roads shaped the home range of spider monkeys and which road features affected their movement. Only 18 percent (3 km) of the spider monkeys' home range perimeter bordered with roads; these roads had greater habitat disparity between road sides than roads inside the home range. Although monkeys were reluctant to be close to roads, and roadside habitat contained low proportions of mature forest, spider monkeys crossed roads at 69 locations (7.5 crossings per kilometer). The main road characteristic affecting crossings was canopy opening size, with greater probability of crossing where canopy openings were smaller. Our findings support the importance of canopy opening size for road crossing of arboreal taxa, but they also indicate the relevant role roadside forest structure may have. Minimizing canopy opening size and forest disturbance along roads can facilitate the movement of arboreal fauna and preserve the important role of spider monkeys and other arboreal taxa in seed dispersal and thus the maintenance and regeneration of forest diversity. © 2017 The Association for Tropical Biology and Conservation

Humid tropical rain forest has expanded into eucalypt forest and savanna over the last 50 years

Tropical rain forest expansion and savanna woody vegetation thickening appear to be a global trend, but there remains uncertainty about whether there is a common set of global drivers. Using geographic information techniques, we analyzed aerial photography of five areas in the humid tropics of northeastern Queensland, Australia, taken in the 1950s and 2008, to determine if changes in rain forest extent match those reported for the Australian monsoon tropics using similar techniques. Mapping of the 1950s aerial photography showed that of the combined study area (64,430 ha), 63% was classified as eucalypt forests/woodland and 37% as rain forest. Our mapping revealed that although most boundaries remained stable, there was a net increase of 732 ha of the original rain forest area over the study period, and negligible conversion of rain forest to eucalypt forest/woodland. Statistical modeling, controlling for spatial autocorrelation, indicated distance from preexisting rain forest as the strongest determinant of rain forest expansion. Margin extension had a mean rate across the five sites of 0.6 m per decade. Expansion was greater in tall open forest types but also occurred in shorter, more flammable woodland vegetation types. No correlations were detected with other local variables (aspect, elevation, geology, topography, drainage). Using a geographically weighted mean rate of rain forest margin extension across the whole region, we predict that over 25% of tall open forest (a forest type of high conservation significance) would still remain after 2000 years of rain forest expansion. This slow replacement is due to the convoluted nature of the rain forest boundary and the irregular shape of the tall open forest patches. Our analyses point to the increased concentration of atmospheric CO2 as the most likely global driver of indiscriminate rain forest expansion occurring in northeastern Australia, by increasing tree growth and thereby overriding the effects of fire disturbance

More than just trees: Assessing reforestation success in tropical developing countries

Rural communities in many parts of the tropics are dependent of forests for their livelihoods and for environmental services. Forest resources in the tropics have declined rapidly over the past century and therefore many developing countries in the tropics have reforestation programs. Although reforestation is a long-term process with long-term benefits, existing evaluations of the success of these programs tends to focus on short-term establishment success indicators. This paper presents a review of reforestation assessment that highlights the need to not only consider short-term establishment success, but also longer-term growth and maturation success, environmental success and socio-economic success. In addition, we argue that reforestation assessment should not be based on success indicators alone, but should incorporate the drivers of success, which encompasses an array of biophysical, socio-economic, institutional and project characteristics. This is needed in order to understand the reasons why reforestation projects succeed or fail and therefore to design more successful projects in future. The paper presents a conceptual model for reforestation success assessment that links key groups of success indicators and drivers. This conceptual model provides the basis for a more comprehensive evaluation of reforestation success and the basis for the development of predictive systems-based assessment models. These models will be needed to better guide reforestation project planning and policy design and therefore assist rural communities in tropical developing countries to alleviate poverty and achieve a better quality of life

Species diversity in restoration plantings: important factors for increasing the diversity of threatened tree species in the restoration of the Araucaria forest ecosystem

The Araucaria forest ecosystem in southern Brazil is highly threatened: less than one percent of the original forest remains, and what is left is a fragmented agro-mosaic of mostly early-to-late secondary forest patches among high-yield agriculture and timber monocultures. Forest restoration initiatives in this region aim to restore degraded areas, however the limited number of species used in restoration projects represents a missed opportunity for species-rich plantings. High diversity plantings represent a larger number of functional groups and provide a targeted conservation strategy for the high number of threatened species within this ecosystem. This study interviewed nurseries (Ns) and restoration practitioners (RPs) in Paraná and Santa Catarina states to identify what species are being cultivated and planted, and what factors are driving the species selection process. An average of 20 species were reportedly used in restoration plantings, most of which are common, widespread species. Baseline data confirms that Ns and RPs have disproportionately low occurrences of threatened species in their inventories and plantings, supporting findings from previous research. Questionnaire responses reveal that opportunities for seed acquisition are an extremely important factor in order for nurseries to increase their diversity of cultivated species. Results also suggest that facilitating species-rich plantings for restoration practitioners would only be feasible if it did not increase the time required to complete planting projects, as it would minimize their ability to keep costs low. This study proposes solutions for increasing the number of species used in restoration practice—such as developing a comprehensive species list, fostering knowledge-sharing between actors, creating seed sharing programs, and increasing coordination of planting projects. Long-term strategies involve complimenting traditional ex situ approaches with emerging inter-situ and quasi in situ conservation strategies which simultaneously provide long-term preservation of genetic diversity and increase seed production of target species