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Digitisation of this thesis was sponsored by Arcadia Fund, a charitable fund of Lisbet Rausing and Peter Baldwin.

The giant tortoises of the Galapagos have become greatly depleted since European discovery of the islands in the 16th Century, with populations declining from an estimated 250000 to between 8000 and 14000 in the 1970s. Successful tortoise conservation efforts have focused on species recovery, but ecosystem conservation and restoration requires a better understanding of the wider ecological consequences of this drastic reduction in the archipelago's only large native herbivore. We report the first evidence from palaeoecological records of coprophilous fungal spores of the formerly more extensive geographical range of giant tortoises in the highlands of Santa Cruz Island. Upland tortoise populations on Santa Cruz declined 500-700years ago, likely the result of human impact or possible climatic change. Former freshwater wetlands, a now limited habitat-type, were found to have converted to Sphagnum bogs concomitant with tortoise loss, subsequently leading to the decline of several now-rare or extinct plant species.

Galapagos is a natural laboratory offering a great opportunity to study plants functional traits. This study characterises morphological and ecophysiological responses of Croton scouleri, an endemic tree that habits from humid and upper elevations to semiarid lowlands, throughout an altitudinal gradient and in a manipulative experiment. Croton scouleri trees were gradually smaller with less total leaf area due to a gradual reduction in mean leaf size, and they folded their leaves at lower elevations. These results were also recorded after cutting every deep root. Two physiological traits that allowed Croton scouleri to avoid damages to the photosynthetic apparatus were detected between 30 and 150 m a.s.l. Lower variable fluorescence (Fv) and basal fluorescence (F0) keeping constant maximum photochemical efficiency of PSII (Fv/Fm) denoted a drop in chlorophyll concentration. Concomitantly, the recorded increase in the Quantum efficiency of PSII ( PSII) with similar Fv/Fm means that Croton scouleri could be using cyclic electron transport as photoprotective mechanism. On the other hand, a deep root system to reach the water table allowed Croton scouleri to behave as a drought-avoider, which was reflected in: (1) unvarying water status Leaf Water Content and Relative Water Content were always higher than 69 and 58%, respectively; (2) stable and low photoinhibition levels; and (3) unvarying leaf area index. However, Croton scouleri was not able to avoid drought at altitudes lower 30 m a.s.l. where similar responses to those recorded after root cutting were recorded. Junta de Andalucía AI60/04

We review recommendations made since the founding of the Charles Darwin Foundation in 1959, concerning botanical research for the conservation of Galapagos, and present our suggestions for priorities for the immediate future.

CDRS Research Highlights, 2004. Plants. Social Sciences. Vertebrates. Invasive Species Total Control Plan. Terrestrial Invertebrates. Project Isabela. Marine Sciences.

Seeds of 14 plant species extracted from food products proposed for field trips in Galapagos were tested for viability. Strawberry Fragaria ananasa and Blackberry Rubus glaucus jams (Snob and Gustadina brands) contained no viable seeds. Schullo brand granola contained inviable Sesame Sesamum indicum seed, but Sesame in granolas prepared in Galapagos was viable. Sesame seed in bread was viable but Flax Linum usitatissimum seed in bread was not. Brown Rice Oryza sativa and Sunflower seeds Helianthus annuus were both viable. Fresh Apple Malus domestica, Naranjilla Solanum quitoense, Cucumber Cucumis sativus, Pineapple Ananas comosus, Pear Pyrus communis, Bell Pepper Capsicum annuum, Tomato Solanum lycopersicum, Grape Vinis vinifera all contained viable seeds. We recommend prohibiting any product with viable seeds from field trips to uninhabited areas. CDF Contribution Number 1009.

Darwin Initiative for Biodiversity Conservation (UK) Global Environment Facility (World Bank)