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T he “F oliage is the F ruit” hypothesis: B uchloe dactyloides ( P oaceae ) and the shortgrass prairie of N orth A merica
Author(s) -
Quinn James A.,
Mowrey Daniel P.,
Emanuele Stephen M.,
Whalley Ralph D. B.
Publication year - 1994
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1994.tb11465.x
Subject(s) - biology , bouteloua gracilis , herbivore , seed dispersal , biological dispersal , steppe , germination , seedling , zoology , botany , agronomy , grazing , ecology , population , demography , sociology
Janzen proposed that foliage of herbaceous plants may serve as the attractant for large herbivore dispersal of seeds. Such herbivore dispersal was envisioned to select for traits enhancing ingestion and passage of viable seeds through the animal. We tested this “Foliage is the Fruit” (FF) hypothesis by collecting and collating appropriate data from Buchloe dactyloides ( buffalograss), one of the two dominant grasses of the shortgrass prairie. Passage of buffalograss diaspores through cattle had a positive effect on germination and seedling growth from intact diaspores, damage other than that due to mastication (15%) was minimal, and retention time was 1–5 days. This combination of retention time and migratory herbivores during the northward expansion of shortgrass prairie should have enhanced migration of buffalograss northward to Montana from its area of origin in central Mexico, and our comparisons with its five close dioecious relatives (the “Buchloe group”) showed that buffalograss does possess a suite of distinctive FF traits. Lab analyses of foliage quality and digestibility also confirmed the high quality of its foliage. After reviewing comparable data for Bouteloua gracilis ( blue grama), we conclude that buffalograss and blue grama, which dominate major portions of the largest North American steppe Province, provide strong support for the FF hypothesis.