TY - JOUR
T1 - Seed-caching responses to substrate and rock cover by two Peromyscus species
T2 - Implications for pinyon pine establishment
AU - Pearson, Kristen M.
AU - Theimer, Tad C.
PY - 2004/9
Y1 - 2004/9
N2 - We examined whether pinyon mice (Peromyscus truei) and brush mice (P. boylii) could act as directed dispersal agents of pinyon pine (Pinus edulis) through differential responses to soil particle size and rock cover. In field experiments, we allowed mice to either cache pinyon seeds or recover artificially cached seeds (pilfer) from quadrats containing large- or small-particle soils. Both species placed most (70%) seed caches in small-particle soil. Pilfering was the same from both particle sizes in the first year, while more seeds were pilfered from large-particle soils in the second year. In separate experiments, rock cover interacted with soil particle size, with both species placing over 50% of their caches in small-particle soil with rock cover. Overall, we found greater seed-caching in small-particle soils near rocks, with equal or lower pilfering from small-particle soils, suggesting more seeds would survive in small-particle soils near rock cover. Three lines of evidence supported the hypothesis that mice could act as directed dispersers by moving pinyon seeds to beneficial microsites for germination and establishment. First, in greenhouse experiments, pinyon seed germination was 4 times greater in small-particle soil cores than in large-particle soil cores. Second, soils near rocks had significantly higher water content than areas of open soil at the driest time of the year, a critical factor for seedling survival in the arid southwestern USA. Third, 75% of juvenile pinyon trees were growing in small-particle soils, and 45% were growing near rock nurses.
AB - We examined whether pinyon mice (Peromyscus truei) and brush mice (P. boylii) could act as directed dispersal agents of pinyon pine (Pinus edulis) through differential responses to soil particle size and rock cover. In field experiments, we allowed mice to either cache pinyon seeds or recover artificially cached seeds (pilfer) from quadrats containing large- or small-particle soils. Both species placed most (70%) seed caches in small-particle soil. Pilfering was the same from both particle sizes in the first year, while more seeds were pilfered from large-particle soils in the second year. In separate experiments, rock cover interacted with soil particle size, with both species placing over 50% of their caches in small-particle soil with rock cover. Overall, we found greater seed-caching in small-particle soils near rocks, with equal or lower pilfering from small-particle soils, suggesting more seeds would survive in small-particle soils near rock cover. Three lines of evidence supported the hypothesis that mice could act as directed dispersers by moving pinyon seeds to beneficial microsites for germination and establishment. First, in greenhouse experiments, pinyon seed germination was 4 times greater in small-particle soil cores than in large-particle soil cores. Second, soils near rocks had significantly higher water content than areas of open soil at the driest time of the year, a critical factor for seedling survival in the arid southwestern USA. Third, 75% of juvenile pinyon trees were growing in small-particle soils, and 45% were growing near rock nurses.
KW - Coexistence
KW - Directed dispersal
KW - Pilferage
KW - Pinus edulis
KW - Soil particle size
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U2 - 10.1007/s00442-004-1638-8
DO - 10.1007/s00442-004-1638-8
M3 - Article
C2 - 15258848
AN - SCOPUS:4944239072
SN - 0029-8549
VL - 141
SP - 76
EP - 83
JO - Oecologia
JF - Oecologia
IS - 1
ER -