EVOLUTIONARY CONSEQUENCES OF FOOD-CHAIN LENGTH IN KELP FOREST COMMUNITIES

被引:94
作者
STEINBERG, PD
ESTES, JA
WINTER, FC
机构
[1] UNIV CALIF SANTA CRUZ,NATL BIOL SERV,SANTA CRUZ,CA 95064
[2] UNIV NEW S WALES,SCH BIOL SCI,KENSINGTON,NSW 2033,AUSTRALIA
[3] UNIV AUCKLAND,LEIGH MARINE LAB,WARKWORTH,NEW ZEALAND
关键词
BIOGEOGRAPHY; COEVOLUTION; HERBIVORY; PHLOROTANNINS; PREDATION;
D O I
10.1073/pnas.92.18.8145
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Kelp forests are strongly influenced by macroinvertebrate grazing on fleshy macroalgae. In the North Pacific Ocean, sea otter predation on macroinvertebrates substantially reduces the intensity of herbivory on macroalgae. Temperate Australasia, in contrast, has no known predator of comparable influence, These ecological and biogeographic patterns led us to predict that (i) the intensity of herbivory should be greater Tn temperate Australasia than in the North Pacific Ocean; thus (ii) Australasian seaweeds have been under stronger selection to evolve chemical defenses and (iii) Australasian herbivores have been more strongly selected to tolerate these compounds. We tested these predictions first by measuring rates of algal tissue loss to herbivory at several locations in Australasian and North Pacific kelp forests. There were significant differences in grazing rates among sea otter-dominated locations in the North Pacific (0-2% day(-1)), Australasia (5-7% day(-1)), and a North Pacific location lacking sea otters (80% day(-1)). The expectations that chronically high rates of herbivory in Australasia have selected for high concentrations of defensive secondary metabolites (phlorotannins) in brown algae and increased tolerance of these defenses in the herbivores also were supported. Phlorotannin concentrations in kelps and fucoids from Australasia were, on average, 5-6 times higher than those in a comparable suite of North Pacific algae, confirming earlier findings, Furthermore, feeding rates of Australasian herbivores were largely unaffected by phlorotannins, regardless of the compounds' regional source, North Pacific herbivores, in contrast, were consistently deterred by phlorotannins from both Australasia and the North Pacific, These findings suggest that top-level consumers, acting through food chains of various lengths, can strongly influence the ecology and evolution of plant-herbivore interactions.
引用
收藏
页码:8145 / 8148
页数:4
相关论文
共 36 条
[11]  
FOX LR, 1981, AM ZOOL, V21, P853
[12]   FOOD-CHAIN DYNAMICS - THE CENTRAL THEORY OF ECOLOGY [J].
FRETWELL, SD .
OIKOS, 1987, 50 (03) :291-301
[13]  
FRETWELL SD, 1977, PERSPECT BIOL MED, V20, P169
[14]  
Futuyma D. J., 1983, COEVOLUTION
[15]   COMMUNITY STRUCTURE, POPULATION CONTROL, AND COMPETITION [J].
HAIRSTON, NG ;
SMITH, FE ;
SLOBODKIN, LB .
AMERICAN NATURALIST, 1960, 94 (879) :421-425
[16]  
Hay M.E., 1991, P96
[17]  
Hay Mark E., 1992, P371
[18]   MARINE PLANT-HERBIVORE INTERACTIONS - THE ECOLOGY OF CHEMICAL DEFENSE [J].
HAY, ME ;
FENICAL, W .
ANNUAL REVIEW OF ECOLOGY AND SYSTEMATICS, 1988, 19 :111-145
[20]  
HAY ME, 1985, 5TH P INT COR REEF C, V4, P29