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Conifer Seed Survival in a Western Oregon Clearcut
Author(s) -
Gashwiler Jay S.
Publication year - 1967
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1932678
Subject(s) - tsuga , germination , thuja , western hemlock , biology , seed predation , douglas fir , horticulture , botany , ecology , seed dispersal , population , biological dispersal , demography , sociology
A study of the survival of naturally disseminated tree seed was made in a clearcut area on the H. J. Andrews Experimental Forest in the Cascade Range of western Oregon during 1955–60. From start of seed fall until the end of germination in late spring following year, 12% of the Douglas‐fir (Pseudotsuga menziesii) seed survived. Ground‐feeding birds and small mammals caused 63% of the seed loss and other agents 25%. Thirty‐one per cent of the seed of western hemlock (Tsuga heterophylla) lived from the start of seed fall until the end of germination. Of the amount lost, birds and mammals took 16% and all other factors 53%. A large proportion (65%) of western redcedar (Thuja plicata) seed survived during the same period. The entire loss was attributed to causes such as nonviable filled seeds, disease, invertebrates, and others. Ground‐feeding birds and small mammals showed a definite preference for Douglas‐fir seeds. Only about 25% as many hemlock seeds were taken, and redcedar was not consumed in appreciable amounts. Most of the seed depredations by birds and mammals occurred from start of seed fall to start of germination; other factors took heaviest toll during the germination period.