scholarly journals On the Composition of Forest Humus Layer (H Layer.)

1942 ◽  
Vol 18 (9) ◽  
pp. 866-868
Author(s):  
R. KAWASHIMA ◽  
M. NAGATA ◽  
G. SUYAMA
Keyword(s):  
Soil Science ◽  
2019 ◽  
Vol 184 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Martin Maier ◽  
Verena Lang

1992 ◽  
Vol 57 ◽  
Author(s):  
D. Maddelein ◽  
N. Lust

The  study of a seventy years old stand of Scots pine on drift sands proves that  Scots pine growth on these sites was and is still relatively good: average  diameter 27.6 cm, average height 19.4 m, standing volume 213 m3 and an annual increment  of 4.9 m3.ha-1.yr-1. All Scots pines  belong to the upper storey. Yet considerable differences in crown development  and vitality are observed. The current growth rate and the spontaneous  settlement of pine seedlings under canopy show the ideal conditions for the  creation of a high forest with reserves. Anyway a rotation period of more  than 70 years is recommendable.     On several places a consolidated regeneration of Scots pine seedlings under  canopy occur. Groups with a stem number of 700 to 3,500 seedlings per are, ranging  in age from 3 to 11 years and in height from 10 to 170 cm, are present. This  Scots pine regeneration has developed in a normal mor humus layer and in a  dense Deschampsia mat.      Broadleaved regeneration is not so abundant, and consists for 75 % of black  cherry. Absence of seed trees, browsing damage and the exclusive character of  black cherry are the limiting factors for the installation and survival of  valuable indigenous species, such as pedunculate oak.     Provided that black cherry is removed and that the regeneration is  protected against wild damage, it is possible to create a mixed forest  dominated by Scots pine but with a considerable admixture of indigenous  broadleaved trees. However, if black cherry will not be sufficiently  controlled, it can be expected that in a first phase black cherry will  dominate the understorey, that it will prevent the regeneration of all other  species and that, very soon, it will form an almost single-species dominated  stage in forest succession.


1999 ◽  
Vol 64 ◽  
Author(s):  
K. M. Tabari ◽  
N. Lust

Monitoring  of natural regeneration in a dense semi-natural mixed hardwood forest on the  base    of ash, beech, oak and sycamore occurred over 3 years in the Aelmoeseneie  experimental    forest, Belgium. 40 permanent plots (4 m x 5 m) were selected in three  various humus types,    located in an ash stand and in an oak - beech stand. In all plots abundance  and top height of all    broad leaved regenerated species were determined at the end of the growing  seasons 1995 and    1998. In addition, the seedlings which appeared in the plots during 1996  and 1997 were    identified and followed up.    This study proves that in the investigated sites natural regeneration is  drastically poor and    diversity is low, in particular where the humus layer is more acidic (mull  moder) and the litter    layer is thick. No regeneration phase older than the seedling stage (h <  40 cm) is developed on    the different humus types. On average, total number of seedlings in 1995  amounts to 38    units/are in the ash stand and to 63 units/are in the oak - beech stand.  Survival rate over a 3-    year period is 37% and 42% respectively in the ash and oak - beech stands.  Total ingrowth    during the growing seasons 1996 and 1997 is virtually poor, indicating 16  and 8 units/are    respectively in above mentioned stands. Survival rate of occurring  seedlings, as well as the ingrowth of new seedlings are notably different (P < 0.05) according to the soil conditions of the    ash stand. Generally, the low presence of seedlings and the lack of  regeneration older than the    seedling stage reveal that the regeneration development encounters with a  critical problem. The    continuation of this process would likely result in a progressive  succession by the invasive and    the unwanted tree species.


1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling


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