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

We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.

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The worldwide leaf economics spectrum

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Physiological and ecological constraints play key roles in the evolution of plant growth patterns, especially in relation to defenses against herbivores. Phenotypic and life history theories are unified within the growth-differentiation balance (GDB) framework, forming an integrated system of theories explaining and predicting patterns of plant defense and competitive interactions in ecological and evolutionary time. Plant activity at the cellular level can be classified as growth (cell division and enlargement) of differentiation (chemical and morphological changes leading to cell maturation and specialization). The GDB hypothesis of plant defense is premised upon a physiological trade-off between growth and differentiation processes. The trade-off between growth and defense exists because secondary metabolism and structural reinforcement are physiologically constrained in dividing and enlarging cells, and because they divert resources from the production of new leaf area. Hence the dilemma of plants: Th...

https://www.jstor.org/stable/pdfplus/2830650.pdf

The dilemma of plants: To grow or defend.

The degree of herbivory and the effectiveness of defense varies widely among plant species. Resource availability in the environment is proposed as the major determinant of both the amount and type of plant defense. When resource are limited, plants with inherently slow growth are favored over those with fast growth rates; slow rates in turn favor large investments in antiherbivore defenses. Leaf lifetime, also determined by resource availability, affects the relative advantages of defenses with different turnover rates. Relative limitation of different resources also constrains the types of defenses. The proposals are compared with other theories on the evolution of plant defenses.

https://science.sciencemag.org/content/sci/230/4728/895.full.pdf

Resource Availability and Plant Antiherbivore Defense

Rates of herbivory and defensive characteristics of young and mature leaves were measured for saplings of 46 canopy tree species in a lowland tropical rain forest (Barro Colorado Island, Panama). Grazing rates were determined in the field for sample periods in the early wet, late wet, and dry seasons. Leaf properties such as pubescence, toughness, water, protein, fiber, and phenolic contents explained over 70W% of the variation among plant species in the rates of herbivory on mature leaves. Leaf toughness was most highly correlated with levels of herbivory, followed by fiber content and nutritive value. Phenol content and phenol: protein ratios were not significantly correlated with damage. Mature leaves of gap-colonizing species were grazed six times more rapidly than leaves of shade- tolerant species. Gap-colonizers have less tough leaves, lower concentrations of fiber and phenolics, higher levels of nitrogen and water, shorter leaf lifetimes, and faster growth rates than do shade- tolerant species. Gap-colonizers did not escape discovery by herbivores to any greater extent than shade-tolerant species, as measured by the spatial distribution of plants or by the intraspecific dis- tribution of herbivore damage under natural or experimentally manipulated conditions. In 70W% of the species, young leaves suffered higher damage levels than mature leaves. Although young leaves are more nutritious and less tough and fibrous, they have two to three times the con- centrations of phenols. The temporal appearance of young leaves was not correlated with the distri- bution of herbivory among individuals of a species. Interspecific patterns of defense mechanisms are discussed in terms of current theories of plant apparency, and an alternative model for the evolution of plant defenses is presented.

Herbivory and defensive characteristics of tree species in a lowland tropical forest

M ost species of higher plants have qualitatively similar resource requirements for growth and reproduction (Chapin et al., p. 49, this issue). They differ, however, in the way they use resources to carry out three essential functions-reproduction, defense against herbivores, and growth. Each of these functions requires a complex set of resources, including carbon, nitrogen, and phosphorus, that make up the structures (leaves, stems, fruits, roots) associated with different functions. Variation in resource allocation occurs through differences in the chemical composition of structures, the relative mass of different structures or organs, and the relative numbers of different structures a plant produces. This variation occurs within individuals through time, within and among populations, and especially among species (Figure 1). Examinations of this variation cross many fields of ecology, including physiological studies of the relationship between structure and function in plants, biochemical studies of

/pdf/allocating-resources-to-reproduction-and-defensenew-c2q4nx59ur.pdf

Allocating Resources to Reproduction and DefenseNew assessments of the costs and benefits of allocation patterns in plants are relating ecological roles to resource use

We suggest here that large-scale natural forest disturbance and primary succession in the lowland rainforests of the Peruvian Amazon is caused by lateral erosion and channel changes of meandering rivers. Our results indicate that in the upper Amazon region, primary succession on newly deposited riverine soils is a major mode of forest regeneration. Landsat imagery analyses show that 26.6% of the modern lowland forest has characteristics of recent erosional and depositional activity; 12.0% of the Peruvian lowland forest is in successional stages along rivers. This successional development is used to classify the western Amazon rainforests according to their geomorphological erosion–deposition pattern. We also propose that by causing high site turnover, disturbance and variation in forest structure, the river dynamics may be a major factor creating and maintaining the high between-habitat (β-type) species diversity characterizing the upper Amazon1.

River dynamics and the diversity of Amazon lowland forest

Fungal endophytes are ubiquitous fungi that inhabit healthy plant tissues without causing disease. Endophytes have been found in every plant species examined to date and may be important, but often overlooked, components of fungal biodiversity. In two sites in a lowland, moist tropical forest of central Panama, we quantified endophyte colonization patterns, richness, host preference, and spatial variation in healthy leaves of two co-occurring, understory tree species [Heisteria concinna (Olacaceae) and Ouratea lucens (Ochnaceae)]. From 83 leaves, all of which were colonized by endophytes, we isolated 418 endophyte morphospecies (estimated 347 genetically distinct taxa), most of which were represented by only a single isolate (59%). Among morphospecies encountered in more than one leaf (nonsingletons), we found evidence of host preference and spatial heterogeneity using both morphospecies frequencies and presence/absence records. Based on these data, we postulate that tropical endophytes themselves may be hyperdiverse and suggest that extrapolative estimates that exclude them will markedly underestimate fungal species diversity.

Phyllis D. Coley

Papers

Resource Availability and Plant Antiherbivore Defense

Herbivory and defensive characteristics of tree species in a lowland tropical forest

Allocating Resources to Reproduction and DefenseNew assessments of the costs and benefits of allocation patterns in plants are relating ecological roles to resource use

River dynamics and the diversity of Amazon lowland forest

Are tropical fungal endophytes hyperdiverse