Maintaining an expert system for the Hubble Space Telescope ground support

The transformation portion of the Hubble Space Telescope (HST) Proposal Entry Processor System converts astronomer-oriented description of a scientific observing program into a detailed description of the parameters needed for planning and scheduling. The transformation system is one of a very few rulebased expert systems that has ever entered an operational phase. The day to day operations of the system and its rulebase are no longer the responsibility of the original developer. As a result, software engineering properties of the rulebased approach become more important. Maintenance issues associated with the coupling of rules within a rulebased system are discussed and a method is offered for partitioning a rulebase so that the amount of knowledge needed to modify the rulebase is minimized. This method is also used to develop a measure of the coupling strength of the rulebase

Response to comment on 'Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity'

Lambert et al. question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species

Forest landscape ecology and global change: an introduction

Forest landscape ecology examines broad-scale patterns and processes and their interactions in forested systems and informs the management of these ecosystems. Beyond being among the richest and the most complex terrestrial systems, forest landscapes serve society by providing an array of products and services and, if managed properly, can do so sustainably. In this chapter, we provide an overview of the field of forest landscape ecology, including major historical and present topics of research, approaches, scales, and applications, particularly those concerning edges, fragmentation, connectivity, disturbance, and biodiversity. In addition, we discuss causes of change in forest landscapes, particularly land-use and management changes, and the expected structural and functional consequences that may result from these drivers. This chapter is intended to set the context and provide an overview for the remainder of the book and poses a broad set of questions related to forest landscape ecology and global change that need answers

The value of plantation forests for plant, invertebrate and bird diversity and the potential for cross-taxon surrogacy

As the area of plantation forest expands worldwide and natural, unmanaged forests decline there is much interest in the potential for planted forests to provide habitat for biodiversity. In regions where little semi-natural woodland remains, the biodiversity supported by forest plantations, typically non-native conifers, may be particularly important. Few studies provide detailed comparisons between the species diversity of native woodlands which are being depleted and non-native plantation forests, which are now expanding, based on data collected from multiple taxa in the same study sites. Here we compare the species diversity and community composition of plants, invertebrates and birds in Sitka spruce- (Picea sitchensis-) dominated and Norway spruce- (Picea abies-) dominated plantations, which have expanded significantly in recent decades in the study area in Ireland, with that of oak- and ash-dominated semi-natural woodlands in the same area. The results show that species richness in spruce plantations can be as high as semi-natural woodlands, but that the two forest types support different assemblages of species. In areas where non-native conifer plantations are the principle forest type, their role in the provision of habitat for biodiversity conservation should not be overlooked. Appropriate management should target the introduction of semi-natural woodland characteristics, and on the extension of existing semi-natural woodlands to maintain and enhance forest species diversity. Our data show that although some relatively easily surveyed groups, such as vascular plants and birds, were congruent with many of the other taxa when looking across all study sites, the similarities in response were not strong enough to warrant use of these taxa as surrogates of the others. In order to capture a wide range of biotic variation, assessments of forest biodiversity should either encompass several taxonomic groups, or rely on the use of indicators of diversity that are not species based

Commercial spruce plantations support a limited. canopy fauna: Evidence from a multi taxa comparison of native and plantation forests

Globally, the total area of plantation forest is increasing as deforestation and fragmentation of native forest continues. In some countries commercial plantations make up more than half of the total forested land. Internationally, there is growing emphasis on forestry policy for plantations to deliver biodiversity and ecosystem services. In Ireland, native forest now comprises just 1% of total land cover while non-native spruce forest makes up 60% of the plantation estate and approximately 6% of the total land cover. The majority of plantation invertebrate biodiversity assessments focus on ground-dwelling species and consequently a good understanding exists for these guilds, especially ground-active spiders and beetles. Using a technique of insecticide fogging, we examine the less well understood component of forest systems, the canopy fauna (Coleoptera, Araneae, Diptera and Hemiptera), in Irish spruce plantations (Sitka and Norway) and compare the assemblage composition, richness and abundance to that of remnant native forest (ash and oak). In addition, we examine the potential for accumulation of forest species in second rotation spruce plantations and identify indicator species for each forest type. From 30 sampled canopies, we recorded 1155 beetles and 1340 spiders from 144 species and over 142 000 Diptera and Hemiptera from 71 families. For all taxa, canopy assemblages of native forests were significantly different from closed-canopy plantation forests. No indicators for plantation forest were identified; those identified for native forest included species from multiple feeding guilds. Plantations supported approximately half the number of beetle species and half the number of Diptera and Hemiptera families recorded in native forests. Although assemblages in Norway spruce plantations were very different to those of native forest, they had consistently higher richness than Sitka spruce plantations. No differences in richness or abundance were found between first rotation and second rotation Sitka spruce plantations. Compared to other forest types, Sitka spruce plantations contained far greater total abundance of invertebrates, due to vast numbers of aphids and midges. Under current management, Sitka spruce plantations provide limited benefit to the canopy fauna typical of native forests in either first or second rotations. The large aphid populations may provide abundant food for insectivores but may also lead to reduced crop production through defoliation. Progressive forestry management should attempt to diversify the plantation canopy fauna, which may also increase productivity and resilience to pest species

Use of micro CHP plants to support the local operation of electric heat pumps

Fig. 1. Global distribution of chytridiomycosis-associated amphibian species declines. Bar plots indicate the number (N) of declined species, grouped by continental area and classified by decline severity. Brazilian species are plotted separately from all other South American species (South America W); Mesoamerica includes Central America, Mexico, and the Caribbean Islands; and Oceania includes Australia and New Zealand. No declines have been reported in Asia. n, total number of declines by region. [Photo credits (clockwise from top left): Anaxyrus boreas, C. Brown, U.S. Geological Survey; Atelopus varius, B.G.; Salamandra salamandra, D. Descouens, Wikimedia Commons; Telmatobius sanborni, I.D.l.R; Cycloramphus boraceiensis, L.F.T.; Cardioglossa melanogaster, M.H.; and Pseudophryne corroboree, C. Doughty