@article {967,
	title = {How leaf domatia and induced plant resistance affect herbivores, natural enemies and plant performance},
	journal = {Oikos},
	volume = {89},
	year = {2000},
	note = {Journal
English
Article
MUNKSGAARD INT PUBL LTD
3
APR
299ZB
COPENHAGEN
Agrawal AA Univ Toronto, Dept Bot, 25 Willcocks St, Toronto, ON M5S 3B2, Canada
OIKOS
35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK},
	month = {2000///},
	pages = {70 - 80},
	abstract = {Predators and plant resistance may act together to control herbivorous arthropod populations or antagonistically, which would reduce the control of pest populations. In a field experiment we enhanced predation by adding simulated leaf domatia to plants. Leaf domatia are small structures that often harbor predaceous arthropods that are potentially beneficial to the plant. We also manipulated host plant duality by inducing resistance with controlled. early season exposure of seedlings to spider mite herbivory. Our manipulations had profound consequences for the natural community of arthropods that inhabited the plants. Leaf domatia had a direct positive effect on abundances of two species of bugs and one species of thrips, all of which are largely predators of herbivores. On leaves with domatia, each of the predators was found inside the domatia two to three times more often than outside the domatia. Eggs of predaceous bugs inside leaf domatia were protected from parasitism compared to eggs outside the domatia. The positive effects of leaf domatia on predator abundances were associated with reduced populations of herbivorous spider mites, aphids, and whiteflies. Plants with experimental leaf domatia showed significantly enhanced reproductive performance. Induced resistance also affected the community of arthropods. Of the abundant predators, all of which also fed on the plant, only minute pirate bugs were negatively affected by induced resistance. Populations of herbivorous spider mites and whiteflies were directly and negatively affected by induction. In contrast, aphid populations were higher on plants with induced resistance compared to uninduced plants. Effects of induced resistance and domatia were additive for each of the predators and for aphids. However, spider mite and whitefly populations were not suppressed Further by employing both induced resistance and domatia compared to each strategy alone. Our manipulations suggest that plant defense strategies can have positive effects on some species and negative effects on others. Negative effects of "resistance trails" on predators and positive effects on some herbivores may reduce the benefits of constitutive expression of resistance traits and may favor inducible defense strategies. Multiple plant strategies such as inducible resistance and morphological traits that aid in the recruitment of predators of herbivores may act together to maximize plant defenses, although they may also be redundant and not act additively},
	keywords = {BIOLOGICAL-CONTROL, COMMUNITIES, COMMUNITY, CONSEQUENCES, COTTON, DECIDUOUS FOREST, DEFENSE STRATEGY, FLOWER THRIPS, food webs, herbivory, HOST-PLANT, multiple, MUTUALISM, NATURAL ENEMIES, POPULATIONS, predation, PREDATOR, predators, RECRUITMENT, SEEDLINGS, SPIDER-MITES, TROPHIC LEVELS},
	isbn = {0030-1299},
	url = {ISI:000086227400008},
	author = {Agrawal,A.A. and Karban,R. and Colfer,R.G.}
}
@article {939,
	title = {Trait-initiated indirect effects due to changes in consumption rates in simple food webs},
	journal = {Ecology},
	volume = {85},
	year = {2004},
	note = {J
APR},
	month = {2004///},
	pages = {1029 - 1038},
	abstract = {This article explores the potential indirect effects due to changes in consumption-related traits of a focal prey species in each of two simple food webs. The systems considered are: one predator exploiting two independent prey, and one predator exploiting two prey that use a common limiting resource. In each system, the indirect effect of a change in a consumption-related parameter of one prey species on the population density of the other prey is determined. When prey only share a predator, the change in one prey{\textquoteright}s density produced by a change in the other prey{\textquoteright}s vulnerability to the predator is determined by whether or not that second prey is initially overexploited; i.e., whether its exploiter{\textquoteright}s intake decreases with an increase in the attack rate. Increases in the vulnerability of an overexploited prey decrease the predator population and thereby indirectly increase the population size of the second prey. Increases in the vulnerability of a prey that is not overexploited have the opposite effects on both the predator and second prey populations. Both of these outcomes can be reversed by strong direct density dependence in the predator, provided the predator exhibits satiation. In the food web with a shared food and a shared resource, increases in predator vulnerability of the more vulnerable prey species always increase the population size of the more resistant prey species. However, increases in the vulnerability of the more resistant prey can either increase or decrease the population size of the more vulnerable prey species. When the more resistant prey becomes better at capturing the resource, the less resistant may either increase or decrease. Overexploitation also explains these outcomes. General principles for understanding the consequences of changes in vulnerabilities or attack rates are discussed},
	keywords = {CONSEQUENCES, DENSITY, DENSITY DEPENDENCE, DENSITY-DEPENDENCE, DEPENDENCE, food web, food webs, FOOD-WEB, indirect effects, POPULATIONS, PREDATOR, PREY, SIZE},
	isbn = {0012-9658},
	url = {ISI:000220766600014},
	author = {Abrams,P.A.}
}
@article {1157,
	title = {The distribution and abundance of animal populations in a climate of uncertainty},
	journal = {Oikos},
	volume = {118},
	year = {2009},
	note = {J
AUG},
	month = {2009///},
	pages = {1121 - 1126},
	abstract = {Current predictions regarding the ecological consequences of climate change on animal populations are generally autecological and species-specific, and/or non-mechanistic extrapolations of recent short-term patterns. To better understand and predict the effects of climate change on the distribution of species and the abundance of populations we offer a novel, broad theoretical framework. Climate-induced changes in trophic structure may actually be more predictable than effects on individual species. The logic is that there are general differences in climatic sensitivity among trophic levels - specifically, that as one moves up trophic levels, there is an increase in the temperature sensitivity of vital rates. More precisely, we provide: (1) a formal mathematical definition of distribution limits that is both operational and conceptual, introducing the concept DL50, defined as the geographic and climatic isoline representing an equilibrium occupancy of half of the suitable habitats; (2) a matrix of the possible changes in trophic structure from climate change and the general theoretical consequences; and (3) a new idea that predicts broad effects of climatic warming on trophic systems. Our intention is to help meet the challenge of developing and testing general theoretical models that can predict which species will be winners and losers in ecological time, which evolutionary traits will be favoured or selected against, and what will be consequences for ecosystem structure and function},
	keywords = {ABUNDANCE, CLIMATE-CHANGE, CONSEQUENCES, PATTERNS, POPULATIONS, TROPHIC LEVELS},
	isbn = {0030-1299},
	url = {ISI:000268535300001},
	author = {Berggren,A. and Bjorkman,C. and Bylund,H. and Ayres,M.P.}
}
