tailieunhanh - Báo cáo lâm nghiệp: " Hazel improves soil quality of sloping oak stands in a German low mountain range"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: " Hazel improves soil quality of sloping oak stands in a German low mountain range" | Ann. For. Sci. 62 2005 23-29 INRA EDP Sciences 2005 DOI forest 2004090 23 Original article Hazel improves soil quality of sloping oak stands in a German low mountain range Dirk Mohr Werner Topp Universitat zu Koln Zoologisches Institut Terrestrische Okologie Weyertal 119 50923 Koln Germany Received 29 October 2003 accepted 14 May 2004 Abstract - We compared Quercus petraea monocultures with adjacent mixed oak-hazel Corylus avellana stands at gentle 14 and steep 25 slopes of the Ahr-Eifel. The influence of hazel on forest floor mass soil nutrients microbial properties and on the abundance of Lumbricidae was studied. Litter mass was greater in mixed stands than in oak monocultures resulting in a thicker Ah-horizon. Additionally the PO43- Ca2 - and Mg2 -contents were higher and the Al3 -content lower in the upper soil of mixed stands. In contrast the contents of organic carbon total nitrogen and the C N ratio did not differ between the two soils. Basal respiration specific microbial activity ợCOt and carbon mineralisation Cmin were higher in mixed stands than in oak monocultures. Lumbricidae showed low densities in three of the stands studied 15-21 ind. m1 2 and were almost absent at the oak monoculture on the steep terrain 2 ind. m2 . oak hazel decomposition soil nutrients Lumbricidae Résumé - Le noisetier améliore la qualité du sol des peuplements de chênes de basse montagne en Allemagne. Nous avons compare des monocultures de type Quercuspetraea avec des cultures adjacentes mixtes composées de chênes et de noisetiers Corylus avellana situées sur des pentes 14 25 differentes. L influence du noisetier sur la masse de litière les substances nutritives du sol les propriétés microbiennes et l abondance de Lumbricidae at été étudiée. Cette étude a montré que la masse de litière est plus élevée dans les cultures mixtes que dans les monocultures de chênes il en résulte un épaississement de l horizon Ah. En outre les teneurs en PO43- -P Ca2 - et Mg2 - sont plus .