. Germination and early growth of coastal tree species on organic seed beds. Germination; Trees Growth. in coastal Oregon, were found on logs (fig. 1). Both seedling and mature hemlock and Sitka spruce trees with both solid cores and cores in several stages of decay Figure 1. —Three hemlocks growing on a completely rotten log. The smallest seedling at left (roots exposed) is 18 years old and 2 meters tall. The middle tree is 8-centimeters , and the large tree at right is 60-centimeters Logs on which seedlings were growing were compared with the surround- ing forest floor to deter
. Germination and early growth of coastal tree species on organic seed beds. Germination; Trees Growth. in coastal Oregon, were found on logs (fig. 1). Both seedling and mature hemlock and Sitka spruce trees with both solid cores and cores in several stages of decay Figure 1. —Three hemlocks growing on a completely rotten log. The smallest seedling at left (roots exposed) is 18 years old and 2 meters tall. The middle tree is 8-centimeters , and the large tree at right is 60-centimeters Logs on which seedlings were growing were compared with the surround- ing forest floor to determine why the logs made better seed beds in moderate and heavy shade than the forest floor. Apparently moisture differences between forest floor duff and rotten wood were not responsible. Although rotten wood retained more moisture than duff, both remained moist throughout the summer in the heavily shaded areas where seed bed differences were most evident. Nor did log elevation above the surrounding forest floor seem to be responsible for the log-forest floor difference. Occasional hemlock seedlings were found grow- ing on the level forest floor in heavy shade but only over buried pieces of rotten wood (fig. 2). The forest floor duff seemed thicker over these buried pieces of rotten wood than over the adjacent mineral soil. Reexamination of the rotten logs showed that those logs supporting seedlings also had thick duff accumula- tions. Accordingly, paired measurements of duff thickness on rotten wood and mineral soil were made in 50 shaded areas. The duff varied greatly, but accu- mulations were significantly thicker over buried pieces of rotten wood and on the tops of rotten logs where seedlings occurred than they were over mineral soil. Duff apparently decomposes more slowly over rotten wood than it does over mineral soil. 3. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance
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Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectgermination
