MD. HASANUZZAMAN
Forestry and Wood Technology Discipline, Life Science School, Khulna University, Khulna - 9208, Bangladesh.
MAHMOOD HOSSAIN
Forestry and Wood Technology Discipline, Life Science School, Khulna University, Khulna - 9208, Bangladesh.
Agro forestry, Cropland, Leaf litter, Litter production, Nutrients
Khulna, Jessore and Satkhira
Resource Development and Management
Agroforestry, Leaf litter
Description of the study area Bangladesh is located between 20°34'-26°3' N; and 88°01'-92°41' E and bordered by the Bay of Bengal on the South and India on all other sides along with small part of Myanmar. Southwestern Bangladesh is a low (<10 m above mean sea level) flat, and fertile deltaic plain which is predominated by calcareous to noncalcareous alluvium soils (BBS 2004). Three districts (administrative unit) i.e. Khulna, Jessore and Satkhira were selected from southwestern Bangladesh, that lies between 22°44'-23°14' N and 89°01'-89°36' E. A tropical to subtropical monsoon climate characterizes this region with three distinct seasons i.e. summer (March–May), rainy (June–October), and winter (November–February). The monthly average rainfall is 155 mm, the highest average rainfall (339 mm) occurs during the month of June to September and the lowest average rainfall (16 mm) occurs in the month of November to February of the study area. January is the coldest month and May is the warmest month of the years. The mean annual temperature is 26 °C with a range of 22–31 °C (Kabir and Webb 2008). The average relative humidity is the highest (86%-88%) during the month of July to August and the lowest (72%-74%) during February to April.
Litter production The total height (m) and DBH (Diameter at Breast Height) of S. macrophylla, M. indica, Z. jujuba, L. chinensis, A. saman, A. heterophyllus, A. indica, M. azadirachta, K. anthotheca, E. camaldulensis, A. auriculiformis and D. sissoo in the cropland agro forests of the study area were measured. Five individual of each species with average DBH were selected for litter production experiment. Whole tree covering method of litter production (Brown 1984) was followed for six months from November 2011 to April 2012 (end of dry month). Litter was collected on weekly basis and the collected litter was sorted into leaves, small branches, flowers, fruits and miscellaneous materials. The litter parts were then oven dried and weighted. The weekly rate of litter production was also calculated. Moreover, the length, width and leaf litter area of individual species were measured by using a leaf area meter (CI-202, CID, Inc, Washington, U.S.A.).
Nutrients in leaf litter The oven-dried leaf litter samples of individual species were grounded, processed and acid digestion according to (Allen 1974). The digested sample extracts were processed according to (Weatherburn 1967) and (Timothy et al 1984) to measure nitrogen and phosphorus concentration in sample extracts respectively using UV-Visible Recording Spectrophotometer (U-2910, HITACHI, Japan). Potassium concentration in sample extracts was also measured by Flame photometer (PFP7, Jenway LTD, England). The amount of nutrient in leaf litter was estimated from mass of leaf litter and the concentrations of respective nutrients in leaf litter.
Statistical analysis The weekly rate of litter production of the studied species were compared by one-way analysis of variance (ANOVA) followed by DMRT (Duncan Multiple Range Test) using SAS statistical software. The relationship among the rate of litter production and climatic factors (rainfall and wind speed) were evaluated by correlation analysis using SAS statistical software. Nutrients (N, P and K) concentration in leaf litter of different tree species was compared by one-way analysis of variance (ANOVA) using SAS statistical software.
Agriculture & Forestry, Vol. 60. Issue 1: 221-233, 2014, Podgorica
Journal