Food shortage, egg resorption Unknown Parasitoids Cone crop, food quantity Tree age and variation Frond quality? Moskovsoe obschchestvo ispytatelei prirody, Moscow. North Carolina State University Press, Raleigh. Hypothesis erection and testing was not a mode of enquiry in most studies. The huge diversity of insect herbivores provides the immense comparative power necessary for a strong evolutionary study of ecological principles. Plant Type Annuals and Biennials Early Succession Fig. Effects of resource distribution on animal--plant interactions.
The comparative approach is then extended in Chapter 6 to other taxa with similar constraints but more divergent phylogeny. The body of facts consistent with the pluralistic theory is extensive. Dynamics of forest insect populations: Patterns, causes, implications. Hunter and Price 1998 or weather Williams and Liebhold 1995, 2000 , or both. There are not 10 million kinds of population dynamics. Population dynamics: New approaches and synthesis. When geographical barriers are absent, we fully expect to observe more or less normal distributions of species over latitudinal, longitudinal, and altitudinal gradients e.
Tamarin 1978 selected two examples to illustrate this point: Howard and Fiske 1911 and Nicholson 1933. In general, then, I see no barriers or impediments in extending the Phylogenetic Constraints Hypothesis to plants. Only a small proportion of studies are on sparsely distributed species, in addition to those mentioned in 2 above: spp. Patterns in the distribution and abundance of insect populations. Conventional wisdom repeatedly emphasized mortality factors.
Much evidence is consistent with the hypothesis but more examples covering the systematic range in a taxon are needed. Some observations on the structure of phytophagous insect communities: The implications for biological control. Dynamics of forest insect populations: Patterns, causes, implications. This would then form the basis for an examination of the extent to which evolutionary factors or ecological factors prevail. The main focus is on plant and herbivore interactions, concentrating on insects. Concerning birds, Ricklefs et al. Principles of population dynamics and their application.
Oxford University Press, Oxford, U. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. Life history correlates of taxonomic diversity. Ecology, life history, and phylogeny of outbreak and nonoutbreak species. The ideas put forth are certainly worthy of consideration by all researchers and students in evolutionary and ecological biology.
A most pleasurable interaction has resulted for which I am grateful. Population processes in the vole and their relevance to general theory. Plant Species Specificity High 8. Dry, poor soils and warm dry summers Natural enemies, warm, dry zones Weather, oak mast, mammals, predation Unknown Weather, parasitoids Weather, viral disease Sunspot activity -- weather in north, predation in south Reduced fecundity, pupal 69%, 36% predation Major factor Mason and Wickman 1988 Bejer 1988 Klimetzek 1990 Schwerdtfeger 1935, 1941 Liebhold et al. Even the subject of plant population dynamics has not entered into the general debate on the topic of causes of population dynamics.
This is not a novel move for it follows a tradition of phylogenetic analysis fostered by Hennig 1950, 1966 and promoted by many authors since, especially in systematics but also in ecology e. On the principles of population dynamics and theoretical models. Multitrophic interactions in terrestrial systems. Emergent impacts of multiple predators on prey. Plant Type Trees Late Succession Fig.
. As Marzluff and Dial point out: Populations with high growth rates, especially very mobile ones, are expected to be good colonists and therefore often encounter new resources. Ordination of evolved traits and ecology on phylogenetic hypotheses presents a challenge but the phylogenetic constraints hypothesis offers the opportunity. No doubt, Varley took his own hopes to heart in designing his study, with Gradwell, on the winter moth, Operophtera brumata, which ran for 19 years from 1950 to 1968 Varley et al. Frequent rejection of the hypothesis that traits act as constraints. The theory, in fact, overemphasizes top-down, negative feedback effects, just as life table development has done, while alternatives are not considered, such as plant quality variation e. Emerson, Orlando Park, Thomas Park, and Karl P.