کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
88351 159299 2010 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The impact of black cottonwood on soil fertility in coastal western hemlock forest
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
پیش نمایش صفحه اول مقاله
The impact of black cottonwood on soil fertility in coastal western hemlock forest
چکیده انگلیسی

Black cottonwood (Populus trichocarpa Torr. and Gray) is a deciduous tree species that extends from Alaska through coastal regions of western Canada into the northwestern United States and as far south as Baja California. We examined the influence of black cottonwood on soil fertility within a forest dominated by Douglas-fir [Pseudotsuga menziessi (Mirb.) Franco], western hemlock [Tsuga heterophylla (Raf.) Sarg], and western red cedar (Thuja plicata Donn ex. D. Don.). Six circular 0.008 ha plots with a single cottonwood tree in the center of conifers were paired with six conifer plots (of the same size) without cottonwood. Litterfall, litter decomposition, properties of forest floor and mineral soil, and N mineralization were compared between plot types. Cottonwood litter had higher concentrations of almost all elements relative to conifer litter. Mass loss did not differ between cottonwood and fir/hemlock litter on cottonwood sites. Twice the amount of mull-like humus form (vermimull and mullmoder, 56%) was found in cottonwood plots compared to 28% in conifer plots. Higher pH (4.4) was found in the forest floor under cottonwood compared to conifer (3.9). Total N concentration (3.33 g/kg) and base saturation (68%) were higher in the mineral soil under cottonwood compared to conifers (2.98 g/kg total N and 50% base saturation). Net ammonification and net mineralization were both lower under cottonwood. These results suggest a variable effect of cottonwood on soil fertility within coastal western hemlock forests with some soil variables changed in a favourable direction and some in an unfavourable direction.

Research highlights▶ Black cottonwood litter did not decompose faster than fir/hemlock litter. ▶ Net mineralization was lower beneath black cottonwood than beneath conifers. ▶ Total N of mineral soil and pH of forest floor were higher under cottonwood trees. ▶ Cottonwood had a variable effect on soil fertility.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Forest Ecology and Management - Volume 260, Issue 8, 15 September 2010, Pages 1350–1358
نویسندگان
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