Effects of carbohydrate applications on growth and vitality of live oak (Quercus virginiana) /
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2010]
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| Online Access: | Link to OAK Trust copy |
| Abstract: | Urban forests grow in stressful environments that can have negative repercussions on tree energy reserves. The goal of this research was to evaluate the impact of exogenously applied carbohydrates on growth and vitality of live oaks (Quercus virginiana P. Miller). An initial study focused on carbohydrate partitioning revealed that annual mean glucose concentration in leaf tissues (49.55 mg·g-1 DW) was almost double that in twigs, trunks, or roots. Starch concentrations in roots and trunks (38.98 and 38.22 mg·g-1 DW of glucose, respectively) were higher during the dormant season and approximately three times the concentrations found in other tissues. An investigation of the effects of exogenous soil applications of glucose and starch on soil microbial activity revealed no significant differences using recoverable viable microbes. However, soil respiration was significantly increased (P<0.05) by glucose a week after application, while higher starch concentrations (120 g·L-1) significantly increased (P<0.05) soil respiration after the fourth week. Although tree soil drenched with carbohydrates in a different study showed significantly (P<0.05) greener leaf color, higher chlorophyll fluorescence, and increased soil respiration at higher concentrations of starch (120 g·L-1), no significant differences were observed in photosynthesis or trunk, canopy, or root growth. Analysis of 13C signatures was unable to detect uptake of exogenous carbohydrates. For trunk-injected trees with glucose and sucrose, trunk growth was significantly (P<0.05) increased by carbohydrate supplementation. Differences were also found in twig glucose content, root starch content, and chlorophyll fluorescence among overall concentration means. A study to compare field diagnostic tools with carbohydrate laboratory analysis established that a portable blood glucose meter can be used to measure glucose content in trees. However, ohm meter, refractometer, chlorophyll fluorescence spectrometer, and iodine staining results did not correlate well with laboratory analysis of carbohydrate concentrations. Results from these studies reveal that soil applied carbohydrates can greatly increase soil microbial activity, provide evidence that trunk-injected carbohydrates may improve growth and vitality of live oaks, and provide a new field diagnostic tool to increase the efficiency of measuring carbohydrates in trees. |
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| Item Description: | "Major Subject: Forestry" Title from author supplied metadata (automated record created 2010-03-12 12:08:51). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |