Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Alpine plant life is proliferating, biodiversity is on the rise and the mountain world appears more productive and inviting than ever. Upper range margin rise of trees and low-altitude (boreal) plant species, expansion of alpine grasslands and dwarf-shrub heaths are the modal biotic adjustments during the past few decades, after a century of substantial climate warming in the Swedish Scandes. This course of biotic landscape evolution has reached historical dimensions and broken a multi-millennial trend of plant cover retrogression, alpine tundra expansion, floristic and faunal impoverishment, all imposed by progressive and deterministic neoglacial climate cooling. Continued modest warming over the present century will likely be beneficial to alpine biodiversity, geoecological stability, resilience, sustainable reindeer husbandry and aesthetic landscape qualities. These aspects are highlighted by an integrative review of results from long-term monitoring of subalpine/alpine vegetation in the Swedish Scandes. This forms the basis for some tentative projections of landscape transformations in a potentially warmer future. Notably, these results and projections are not necessarily valid in other regions and differ in some respects from model predictions. Continued monitoring is mandatory as a basis for generation of more realistic vegetation and ecosystem models.

/pdf/a-richer-greener-and-smaller-alpine-world-review-and-f6k8etoyf6.pdf

A Richer, Greener and Smaller Alpine World : Review and Projection of Warming-Induced Plant Cover Change in the Swedish Scandes

The present cold adapted floras of arctic and alpine regions are frequently considered as being at risk from climatic warming. However, the prospect of higher temperatures liberating large areas of land from permanent ice cover in the Arctic plus a retreat of the nival zone on higher mountains could provide new terrain for the continued existence and expansion of both arctic and alpine floras. Examination in detail of these floras reveals numerous examples of species that have sufficient genetic variability to adapt phenologically and physiologically to warmer and drier conditions. The calcicole flora of the Alps is well placed to withstand the drier conditions that may arise with climatic warming. In the Arctic the polar night will persist whatever changes may take place in the temperature regime. There will therefore always be features of the arctic environment that will be distinctive and can be expected to provide a habitat for a polar flora. The polar bear with its complete dependence on sea ice for ...

Cold climate plants in a warmer world

Fire behaviour and impact on heather moorland

The present-day arctic flora replaced Arcto-Tertiary forest when global temperatures dropped markedly towards the end of the Pliocene 3–4 million years ago. During the Quaternary (from 1.8 mya) recurrent cycles of ice ages (glaciations) interspersed with shorter warmer periods (interglacials) have caused arctic and alpine plants to experience frequent range fragmentations and expansions. The application of molecular phylogenetic and phylogeographic analysis, along with an accumulating body of pollen and macrofossil evidence, is providing a greater understanding of the nature and effects of these events. To report what is new in this regard and also to assess what changes might lie ahead as a result of rapid climate warming, a Botanical Society of Scotland Symposium was held in June 2007 at the University of St Andrews on the History, evolution and future of arctic and alpine flora. This special issue contains papers based on presentations given at this meeting. Its aim is to highlight the fusion of recent...

History, evolution and future of arctic and alpine flora: overview

The threatened arctic-alpine plants in Scotland are described from the results of a comprehensive survey carried out between 1990 and 1996 which attempted to record all populations. The factors affecting the survival of populations of these species are indicated along with the legal measures available for their protection. I consider whether we should protect these species and whether we can. The steps needed to help ensure their survival are suggested. These could include the assessment of the local risk to populations and the implementation of remedial management to threatened populations. Scottish botanists have to decide whether they support such a change in conservation practice for plants.

Can we protect threatened Scottish arctic-alpine higher plants?

Summary Maintaining successful regeneration is clearly essential to the conservation management of threatened plants. We examine some of the considerations necessary to determine whether regeneration is successful.

The importance of regeneration studies to the successful conservation management of Scottish rare plants

Summary Ajuga pyramidalis is a polycarpic, perennial herb which is variable in flowering and population size. It has been recorded from over 200 sites in the Highlands and Islands of Scotland, one in the Lake District and in twelve coastal sites in Ireland. It grows mainly on circum-neutral soils (pH 4.9–6.9) in open grassland and heathland, and upland rock ledges. It does not appear to be under any particular threat in Britain.

Distribution and ecology of pyramidal bugle (Ajuga pyramidalis L., Lamiaceae) in the British Isles

Summary A morphologically distinct variety of Athyrium distentifolium called A. distentifolium var. flexile has been found only in Scotland. Research was undertaken for aUK Biodiversity Action Plan. To confirm that this taxon has a definitely recognisable morphology, a morphometric analysis was used on the range of characters used to define this variety. It showed that it can be clearly differentiated.

A morphometric analysis of Scottish Athyrium distentifolium: a contribution to the BAP

Summary The distributions of Scottish rare plants are well known and we have a good understanding of the communities and habitats in which they occur. But how do we ensure that populations are maintained or enhanced? The ecological processes that determine current population size and distribution must be understood. We review the type of information from monitoring that is required to assess change in species status and to guide conservation management. Managing for habitats must be the right approach to conserving species, but we need to take careful consideration of the individual requirements of different species. Environments fluctuate at a range of spatial and temporal scales; we review the evidence that rare plant species respond to such fluctuations. We consider that there might be a danger that overprotecting some habitats, by trying to maintain constant ideal management prescriptions, might be putting some species at risk. We believe that conservation managers can resolve the apparent conflicts b...

Chris Sydes

Papers

Can we protect threatened Scottish arctic-alpine higher plants?

The importance of regeneration studies to the successful conservation management of Scottish rare plants

Distribution and ecology of pyramidal bugle (Ajuga pyramidalis L., Lamiaceae) in the British Isles

A morphometric analysis of Scottish Athyrium distentifolium: a contribution to the BAP

Promoting survival prospects of rare plants