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Titolo:
MYRMECOPHYTIC CECROPIA - ANTIHERBIVORE DEFENSES UNDER DIFFERENT NUTRIENT TREATMENTS
Autore:
FOLGARAIT PJ; DAVIDSON DW;
Indirizzi:
UNIV BUENOS AIRES,FAC AGRON,DEPT ECOL,AVE SAN MARTIN 4453 RA-1417 BUENOS AIRES DF ARGENTINA UNIV UTAH,DEPT BIOL SALT LAKE CITY UT 84112
Titolo Testata:
Oecologia
fascicolo: 2, volume: 104, anno: 1995,
pagine: 189 - 206
SICI:
0029-8549(1995)104:2<189:MC-ADU>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
LOTUS-CORNICULATUS L; CHEMICAL DEFENSE; NITROGEN-CONTENT; PLANT PHENOLICS; MATURE LEAVES; GROWTH; HERBIVORY; LEAF; BALANCE; TANNIN;
Keywords:
ANTIHERBIVORE DEFENSES; CECROPIA; C-N BALANCE; INTERSPECIFIC COMPARISONS; NUTRIENTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
72
Recensione:
Indirizzi per estratti:
Citazione:
P.J. Folgarait e D.W. Davidson, "MYRMECOPHYTIC CECROPIA - ANTIHERBIVORE DEFENSES UNDER DIFFERENT NUTRIENT TREATMENTS", Oecologia, 104(2), 1995, pp. 189-206

Abstract

In greenhouse experiments, we compared putative biotic, chemical, physical and phenological defenses of six myrmecophytic Cecropia species cultivated under high and low nutrient regimes. We tested the intraspecific predictions of the C:N balance hypothesis for a broader range ofdefenses than included in other studies to date. Treatment effects ondefenses appear to depend on the nutrient constituents of those defenses. Only strictly carbon-based defenses such as tannins and phenolicsreached higher concentrations at the lower nutrient level. The production of glycogen-rich and membrane-bound Mullerian body ant rewards (MBs) increased with greater levels of both nutrients (this study) and light (Folgarait and Davidson 1994). In contrast, lipid- and amino acid-rich pearl body food rewards (PBs) were produced in greater numbers under conditions of high nutrient levels (this study) and low light (Folgarait and Davidson 1994), both of which should have contributed to arelative excess of nitrogen. Nutrient effects on toughness and leaf expansion rates (perhaps serving as phenological defenses) were inconsistent with the predictions of the C:N balance hypothesis. Mature leaves are protected principally by chemical and physical defenses, and newleaves, by biotic defenses. As in a previous study, interspecific comparisons agreed with the resource availability theory of plant defense. Plant investment in immobile defenses (tannins and phenolics, and leaf toughness), and in a defense with high initial construction costs (trichilia differentiated to produce MBs) were greater in each of threecomparatively slow-growing ''gap'' Cecropia typical of small openingsin primary forest, than in closely related and fast-growing ''pioneer'' species of large-scale disturbances (riparian edge and land slips). In contrast, both production of PBs (with negligible initial construction costs) and leaf expansion rates were greater in pioneers than in gap species. Rapid onset of biotic defenses during new leaf development (earlier in pioneers) may reduce new leaf herbivory in all species.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/07/20 alle ore 22:13:48