Variation in parasitoid attraction to herbivore-infested plants and alternative host plant cover mediate tritrophic interactions at the landscape scale

Landscape Ecology - Tritrophic interactions may be affected by local factors and the broader landscape context. At small spatial scales, carnivorous enemies of herbivorous insects use...     

A simple tool for extending agronomic management on a landscape basis

Context

This short communication responds to calls for greater input from agronomists into landscape research as a means of contributing to managing the positive and negative effects of farming systems. This was recognised in New South Wales, Australia in relation to the management of soil acidity in landscapes of variable topography.

Objective

The response was the development of a structured course (Landscan) aimed at educating land managers to match land use with landscape capability. The course characteristics are briefly presented in terms of reading, measuring and interpreting landscape features, understanding degradation processes, assessing available management tools and prioritising actions to balance production, profit and sustainability.

Method

The main features of the course content and mode of delivery are detailed including evaluation of participants in regards to increased knowledge, skills and potential changes in practice.

Results

Over 1000 land managers have completed the course with most indicating that they will alter priorities, change strategies and adjust goals as a result and 97 % indicated they would recommend the workshops to others. The Landscan framework also provides a means for researchers to incorporate their results for rapid uptake as well as identifying research gaps. The course has been used to deliver integrated group outcomes in areas of soil health, biodiversity, water quality and weed management.

Conclusion

The framework addresses the issue of greater involvement of agronomists in landscape research and has successfully initiated dialogue with other disciplines. While the emphasis to date has been on livestock production in variable landscapes the model should be applicable in other farming systems.

     

A positive response of mountain pine beetle to pine forest-clearcut edges at the landscape scale in British Columbia,Canada

In British Columbia, large-scale salvage harvesting has been underway to recover timber value from forest stands infested by mountain pine beetle during the current outbreak. Understanding the response of beetles to clearcut edges particularly at the landscape scale is crucial to understanding the impacts of increased habitat fragmentation due to salvage harvesting on the spread of the beetle infestations. A novel proximity analysis approach based on null models of complete spatial randomness with three different spatial extents was developed to examine the spatial patterns of infestations in relation to cutblocks. Inhomogeneous Poisson point process models were fitted to predict how intensities of infestations varied with distances to the nearest cutblocks. Marked Poisson point process models were also fitted to evaluate the effects of the variables associated with the nearest cutblocks and adjacent infested pine stands on the edge response of beetles. The results clearly illustrated a significant positive edge response of beetles at the landscape scale. The intensities of infestations decreased non-linearly with distances to the nearest cutblocks. The results also suggested that the quality and distribution of key habitat resources could not fully explain the fundamental mechanisms underlying the edge response. The behavioural change of beetle dispersal at edges may also be an important factor contributing to a positive edge response. The results from this study may be useful in improving the efficacy of mountain pine beetle management efforts.     

Fenoxycarb,a selective insecticide for inclusion in integrated pest management systems for pear in the UK

The effects of fenoxycarb, an insect growth regulator, on predatory anthocorids, were tested in comparison with the broad-spectrum insecticide deltamethrin, in pear orchard trials. The results confirmed the effectiveness of fenoxycarb against pear sucker, Cacop- sylla pyricola and revealed no damaging effects on larval or adult anthocorids (mainly Anthocoris nemoralis). Deltamethrin reduced numbers of both C. pyricola and anthocorids, allowing a resurgence of C. pyricola later in the season. Fenoxycarb is shown to be suitable for use in integrated pest management programmes in pear.     

Semi-natural vegetation and its relationship to designated urban green space at the landscape scale in Leeds, UK

The species composition of semi-natural vegetation in urban areas is influenced by a diversity of factors operating at a variety of spatial scales. This study investigates relationships at the landscape scale between species numbers of semi-natural plant communities and variations in the nature of designated urban green space. Species’ records were obtained from a survey of tetrads (2 km × 2 km) across a contiguous central area of built-up landscape and nearby satellite settlements in the metropolitan borough of Leeds, northern England. Plant species were categorised into natives, archaeophytes, neophytes, casuals and conservation-designated species. The type and extent of designated urban green space within a tetrad was determined using GIS. There was more built-up and designated green space area in the central urban area than in the satellite settlements. However, this difference was not reflected statistically significantly in plant category species’ numbers. Numbers of native species correlated positively with areas of green space designated for relatively high nature conservation value. Neophytes and casuals correlated positively with semi-natural green space lacking rare native species or high native species richness but designated principally for local community accessibility. The value of such spaces and the importance of their appropriate management, not only for community benefits like individual physical health and mental well-being, but also for overall urban plant biodiversity, is highlighted.     

A controlled,hierarchical study of habitat fragmentation: responses at the individual,patch, and landscape scale

We compared the performance of individuals and whole populations of meadow voles, Microtus pennsylvanicus, within and between experimentally created habitat fragments of three sizes (1.0, 0.25, and 0.0625 ha) and between a 20-ha fragmented and a 20-ha continuous habitat landscape. We recorded 10,020 captures of 3946 individuals over 17 censuses between June 1993 and October 1994. Five demographic parameters showed significantly different population responses between the two landscapes but no difference in tests comparing fragment size: i.e., mean and peak population densities (the latter, in each of the two growing seasons) averaged 149 to 172% higher, population growth rate averaged 219% higher, and adult recruitment 170% higher in fragmented than in the continuous control landscape. Observations at the individual level (body sizes, rates of reproduction, residence times) suggested that these landscape differences involved enhanced performance of adult females associated with edge habitats rather than differential immigration or emigration. If this turns out to be a common response to fragmentation, the detection of such responses will be greater when comparing fragmented and unfragmented landscapes with qualitatively different structure than for fragments of varied size with differing proportions of edge. That responses to habitat fragmentation may be more evident at the very small (individual) and very large (landscape) scales, but may be obscured at the intermediate spatial scale of fragments, is a proposition that clearly requires more attention.     

A plant resource and experiment management system based on the Golm Plant Database as a basic tool for omics research

Background  

For omics experiments, detailed characterisation of experimental material with respect to its genetic features, its cultivation history and its treatment history is a requirement for analyses by bioinformatics tools and for publication needs. Furthermore, meta-analysis of several experiments in systems biology based approaches make it necessary to store this information in a standardised manner, preferentially in relational databases. In the Golm Plant Database System, we devised a data management system based on a classical Laboratory Information Management System combined with web-based user interfaces for data entry and retrieval to collect this information in an academic environment.     

Out on a limb: habitat use of a specialist folivore, the koala, at the edge of its range in a modified semi-arid landscape

Habitat loss and natural catastrophes reduce the resources available to animals. Species can persist if they have access to additional resources and habitats through the processes of landscape complementation and supplementation. In arid and semi-arid ecosystems, where productivity is limited by precipitation, the impact of landscape change and prolonged drought is severe on specialist species whose range boundaries are limited by aridity. We examined the pattern of occurrence by a specialist arboreal folivore, the koala, at the periphery of its biogeographic range, in a semi-arid rangeland landscape. We used hierarchical mixed modelling to examine the effect of landscape change on koala populations and their habitat use during and after a prolonged drought. We found that the tree species and the distance of a site from water courses were the most important determinants for koala presence in these landscapes. Koalas were predominantly detected in riverine habitat along the water courses, which are primary habitat and provide refugia in times of drought and extreme heat. There was a strong positive effect from the interaction between the amount of primary and secondary habitat in the landscape, although individually, the amount of each of these habitats was not important. This shows koalas will persist in more intact landscapes. There was no difference in habitat use between dry and wet years, but we consider that it can take several wet seasons for koalas to expand into habitats away from water courses.     

The historical use of fire as a land management tool in New Zealand and the challenges for its continued use

Landscape Ecology - New Zealand’s use of fire as a land management tool has had an extensive and lasting impact on New Zealand’s rural landscapes. We reviewed the historical rural use...     

How different ethno-cultural groups value urban forests and its implications for managing urban nature in a multicultural landscape: A systematic review of the literature

Understanding how different ethno-cultural groups value urban nature is important to understand the role of ethno-cultural diversity in urban ecosystem management. Based on a systematic literature review, this paper summarizes the empirical evidence on how different ethno-cultural groups use, perceive, prefer, and assign meaning to urban nature. I use the urban forest, defined here as all the trees in a city, as a proxy to understand this process. The 31 studies reviewed here differ widely in their lines of inquiry, research methods, urban natural setting, and conceptualizations of ethno-cultural identity. Most studies take place in the US and Europe, where the most common definition of an ethno-culturally diverse group is a person of non-European/non-White background. Most studies focus on what these groups like about a particular urban natural setting, such as an urban park; and whether they like more or less trees in a specific context (e.g. urban park). These groups usually prefer passive and social uses of urban natural areas, and more manicured/functional natural landscapes with less trees. The most common meanings associated with urban natural settings dominated by trees are social interaction and integration. The most common explanations on why these differences occur involve theories on socio-economic marginality, collectivist vs. individualist cultures, urban vs. rural lifestyles, and landscapes of origin. Future research on the topic will benefit by differentiating race from ethnicity, capturing intra-ethnic variation, capturing immigrant identities, exploring the different social, cultural, and economic factors that influence values and/or preferences, and focusing on concrete aspects of urban nature, such as urban forests.