. The vegetation of the Siberian-Mongolian frontiers (the Sayansk region). Botany; Botany. where it has on«e been expelled by conflagration. What is the chief cause of this in the present case again, if it be the drought, direct exsiccating seeds and seedlings, or others, as changes in the character of the soil, such as destruction of the mould, a reduction of the mossy cover or the like, is not always easy to settle definitelj^, though the drought in the summer and after-summer may be most likely direct to account for the seedlings exsiccating and being destroyed. F. E. Clements expresses his
. The vegetation of the Siberian-Mongolian frontiers (the Sayansk region). Botany; Botany. where it has on«e been expelled by conflagration. What is the chief cause of this in the present case again, if it be the drought, direct exsiccating seeds and seedlings, or others, as changes in the character of the soil, such as destruction of the mould, a reduction of the mossy cover or the like, is not always easy to settle definitelj^, though the drought in the summer and after-summer may be most likely direct to account for the seedlings exsiccating and being destroyed. F. E. Clements expresses his opinion on this question in his work. Plant Succession (1916) Pag. 70: «With the seedlings of woody plants the cause of the greatest destruction is drouth in midsummer or Fig. 40. A view in tlie south side of tlie Sayansk mountains at an altitude of about;;900 m. above sea-level. Coniferous trees in various stages of exsiccation. This is the primary factor in limiting the ecesis of many conifers, though the «heaving» action of frost is often great or even predominant. The root-system is often inadequate to supply the water necessary to offset the high transpiration caused by conditions at the surface of the soil. Moreover, it is likewise too short to escape the progressive drying- out of the soil itself. In open places in the Rocky Mountains, such as parks, clearings, etc., the late summer modality is excessive, often including all seedlings of the year.» Experience shows that when the forest for some reason or other is expelled from habitats under extreme conditions, near the boundaries of its area, it does not reappear any more. During a chmatic change, however, forests will be able to hnger for a time 68. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Printz, Henrik, 1888-. [Trondhjem] K. N
Size: 1887px × 1323px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1921
