Leaf properties, litter fall, and nutrient inputs of Terminalia ivorensis at different tree stand densities in a tropical timber - food crop multistrata system

2000 ◽  
Vol 30 (9) ◽  
pp. 1400-1409 ◽  
Author(s):  
L Norgrove ◽  
S Hauser
Keyword(s):  
Leaf Area ◽  
Leaf Litter ◽  
Specific Leaf Area ◽  
Nutrient Concentrations ◽  
Litter Production ◽  
Food Crops ◽  
Litter Fall ◽  
Nutrient Inputs ◽  
Area Index ◽  
Tropical Timber

Tree litter fall was monitored for 2 years in two Terminalia ivorensis A. Chev. plantations in the humid tropics of southern Cameroon. The plantations were 6 and 17 years old when they were each thinned to two timber stand densities (TSD) and understorey food crops were introduced. Leaf litter was the predominant litter fraction in all treatments. Treatment means of specific leaf area for T. ivorensis ranged from 83.7 to 100.7 cm2·g-1. Litter-fall production, leaf area per tree, and leaf area index for T. ivorensis were all higher in year 2 than in year 1. There was near complete defoliation of the T. ivorensis stand by Epicerura sp. (Lepidoptera: Notodontidae) caterpillars in the month just before the start of litter-fall sampling. This is the first report of an Epicerura sp. from Cameroon. Terminalia ivorensis leaf litter production per tree, specific leaf area, and leaf litter nutrient concentrations showed few significant differences between TSD treatments. This lack of response suggests that T. ivorensis is a suitable species for growing at stand densities lower than is normal silvicultural practice in association with food crops.

scholarly journals An Improved Canopy Integration Scheme for a Land Surface Model with Prognostic Canopy Structure

2007 ◽  
Vol 20 (15) ◽  
pp. 3902-3923 ◽  
Author(s):  
Peter E. Thornton ◽  
Niklaus E. Zimmermann
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Land Surface ◽  
Temperate Climate ◽  
Integration Scheme ◽  
Surface Model ◽  
Area Index ◽  
Climate System Model ◽  
Community Land Model ◽  
Canopy Model

Abstract A new logical framework relating the structural and functional characteristics of a vegetation canopy is presented, based on the hypothesis that the ratio of leaf area to leaf mass (specific leaf area) varies linearly with overlying leaf area index within the canopy. Measurements of vertical gradients in specific leaf area and leaf carbon:nitrogen ratio for five species (two deciduous and three evergreen) in a temperate climate support this hypothesis. This new logic is combined with a two-leaf (sunlit and shaded) canopy model to arrive at a new canopy integration scheme for use in the land surface component of a climate system model. An inconsistency in the released model radiation code is identified and corrected. Also introduced here is a prognostic canopy model with coupled carbon and nitrogen cycle dynamics. The new scheme is implemented within the Community Land Model and tested in both diagnostic and prognostic canopy modes. The new scheme increases global gross primary production by 66% (from 65 to 108 Pg carbon yr−1) for diagnostic model simulations driven with reanalysis surface weather, with similar results (117 PgC yr−1) for the new prognostic model. Comparison of model predictions to global syntheses of observations shows generally good agreement for net primary productivity (NPP) across a range of vegetation types, with likely underestimation of NPP in tundra and larch communities. Vegetation carbon stocks are higher than observed in forest systems, but the ranking of stocks by vegetation type is accurately captured.

Effects of repeated fertilization on needle longevity, foliar nutrition, effective leaf area index, and growth characteristics of lodgepole pine in interior British Columbia, Canada

2005 ◽  
Vol 35 (2) ◽  
pp. 440-451 ◽  
Author(s):  
Isaac G Amponsah ◽  
Philip G Comeau ◽  
Robert P Brockley ◽  
Victor J Lieffers
Keyword(s):  
British Columbia ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Growth Response ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Nutrient Concentrations ◽  
Area Index ◽  
Needle Longevity ◽  
Effective Leaf Area Index

We investigated the effects of repeated fertilization (either periodically every 6 years or annual fertilization) on needle longevity and growth response in two juvenile lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stands in the interior of British Columbia, Canada. Annual fertilization decreased needle longevity by 23% at the Kenneth Creek site and by 30% at Sheridan Creek, compared with the control treatments at each site. At Sheridan, repeated fertilization significantly increased effective leaf area index, foliated shoot length, and annual shoot growth. However, none of these variables was significantly altered by repeated fertilization at Kenneth. At both locations, fertilization elevated nutrient concentrations in the current year's foliage. Annual fertilization increased nitrogen concentration in mid-crown branches of retained cohorts (1998–2002) at both study sites. Furthermore, annual nitrogen addition apparently induced or exacerbated copper and iron deficiency in these stands, especially at Kenneth Creek, which may be related to the premature loss of foliage. Nutrient imbalance may also be related to poor effective leaf area index and growth response at Kenneth Creek. Stem growth efficiency declined with annual fertilization at Kenneth Creek because of accelerated turnover of needles, increased allocation of growth to branches, and probably reduced photosynthetic capacity.

scholarly journals Specific leaf area and leaf area index in developing stands of Fagus sylvatica L. and Picea abies Karst.

2016 ◽  
Vol 364 ◽  
pp. 52-59 ◽  
Author(s):  
Bohdan Konôpka ◽  
Jozef Pajtík ◽  
Róbert Marušák ◽  
Michal Bošeľa ◽  
Martin Lukac
Keyword(s):  
Picea Abies ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Fagus Sylvatica ◽  
Specific Leaf Area ◽  
Area Index ◽  
Fagus Sylvatica L
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