scholarly journals The Effects of Rhizome Severing and Nutrient Addition on Growth and Biomass Allocation in Diphasiastrum digitatum

2000 ◽  
Vol 90 (2) ◽  
pp. 77 ◽  
Author(s):  
Carrie A. Railing ◽  
Brian C. McCarthy
Keyword(s):  
Biomass Allocation ◽  
Nutrient Addition ◽  
Rhizome Severing

Nutrient availability, dimorphic seed production, and reproductive allocation in the annual grass Amphicarpum purshii

1989 ◽  
Vol 67 (8) ◽  
pp. 2514-2521 ◽  
Author(s):  
G. P. Cheplick
Keyword(s):  
Seed Production ◽  
Biomass Allocation ◽  
Seed Weight ◽  
Growth Period ◽  
Nutrient Addition ◽  
Shoot Biomass ◽  
Growing Period ◽  
Dimorphic Seed ◽  
Disturbed Habitats ◽  
Reproductive Characters

The effect of nutrient addition on dimorphic seed reproduction and biomass allocation was investigated in amphicarpic peanut grass (Amphicarpum purshii Kunth). This annual, which grows in disturbed habitats on the Coastal Plain of eastern North America, produces self-fertilizing cleistogamous spikelets under ground and potentially outcrossing chasmogamous spikelets above ground. For each of three sibling families raised in the greenhouse from aerial seeds, 11 plants were fertilized twice during the growth period while 11 plants received no fertilizer. Total spikelet output and seed weight increased in response to fertilizer addition for both aerial and subterranean reproductive components, but changes were greater for aerial reproduction. Biomass allocation to subterranean spikelets and seeds was unaffected by nutrient addition. As measured by coefficients of variation, phenotypic variation for six aerial reproductive characters was about twice as great as that for six subterranean reproductive characters. Subterranean and aerial seed output were significantly related to shoot biomass for fertilized plants, but only mean aerial seed weight showed a significant relation to biomass when nutrients were not provided. These results support the hypothesis that early subterranean seed production provides reproductive insurance in peanut grass, whereas later aerial reproduction on newly formed tillers allows plants to increase reproductive output at the end of the growing period according to the availability of resources.

scholarly journals Generic Additive Allometric Models and Biomass Allocation for Two Natural Oak Species in Northeastern China

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 715
Author(s):  
Shengwang Meng ◽  
Fan Yang ◽  
Sheng Hu ◽  
Haibin Wang ◽  
Huimin Wang
Keyword(s):  
Biomass Allocation ◽  
Tree Height ◽  
Northeastern China ◽  
Seemingly Unrelated Regression ◽  
Biomass Estimation ◽  
Model Parameters ◽  
Stem Biomass ◽  
Crown Width ◽  
Biomass Models ◽  
Mongolian Oak

Current models for oak species could not accurately estimate biomass in northeastern China, since they are usually restricted to Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) on local sites, and specifically, no biomass models are available for Liaodong oak (Quercuswutaishanica Mayr). The goal of this study was, therefore, to develop generic biomass models for both oak species on a large scale and evaluate the biomass allocation patterns within tree components. A total of 159 sample trees consisting of 120 Mongolian oak and 39 Liaodong oak were harvested and measured for wood (inside bark), bark, branch and foliage biomass. To account for the belowground biomass, 53 root systems were excavated following the aboveground harvest. The share of biomass allocated to different components was assessed by calculating the ratios. An aboveground additive system of biomass models and belowground equations were fitted based on predictors considering diameter (D), tree height (H), crown width (CW) and crown length (CL). Model parameters were estimated by jointly fitting the total and the components’ equations using the weighted nonlinear seemingly unrelated regression method. A leave-one-out cross-validation procedure was used to evaluate the predictive ability. The results revealed that stem biomass accounts for about two-thirds of the aboveground biomass. The ratio of wood biomass holds constant and that of branches increases with increasing D, H, CW and CL, while a reverse trend was found for bark and foliage. The root-to-shoot ratio nonlinearly decreased with D, ranging from 1.06 to 0.11. Tree diameter proved to be a good predictor, especially for root biomass. Tree height is more prominent than crown size for improving stem biomass models, yet it puts negative effects on crown biomass models with non-significant coefficients. Crown width could help improve the fitting results of the branch and foliage biomass models. We conclude that the selected generic biomass models for Mongolian oak and Liaodong oak will vigorously promote the accuracy of biomass estimation.

The effects of tree cover and soil nutrient addition on native herbaceous richness in a neotropical savanna

Biotropica ◽  
2021 ◽  
Author(s):  
Klécia Gili Massi ◽  
Chesterton Ulysses Orlando Eugênio ◽  
Augusto César Franco ◽  
William A. Hoffmann
Keyword(s):  
Soil Nutrient ◽  
Nutrient Addition ◽  
Tree Cover ◽  
Neotropical Savanna
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