1. Differences in xylem and phloem structure in living stumps of Norway spruce (<italic>Picea abies</italic> (L.) Karst.) and silver fir (<italic>Abies alba</italic> Mill.)
- Author
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Gričar, Jožica, Drolc, Miha, Prislan, Peter, and Šircelj, Helena
- Subjects
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TREE felling , *SILVER fir , *TISSUE wounds , *TRACHEARY cells , *SIEVE elements , *NORWAY spruce - Abstract
Living stumps reported in many tree species were the first, circumstantial evidence of root grafting. Although stump overgrowth has been extensively studied in various tree species, anatomical observations have mainly focused on the xylem part. Here, we investigated the xylem and phloem structure in living stumps of two conifer species: Norway spruce (
Picea abies (L.) Karst.) and silver fir (Abies alba Mill.). The mechanism of wound closure was similar in the two species, however, there were differences in the structure of wound tissues in wood and bark. Immediately after the injury, a callus consisting of parenchymal cells was formed, followed by wound-wood with wide increments. In addition, the wood structure and morphology of tracheids were changed. Tracheids lost their typical elongated and tapering structure; instead, numerous crooked and forked tracheids were present. Traumatic resin canals were present in both species but were more abundant inP. abies , which also had normal resin canals. While the structure of the xylem growth rings eventually normalized in both species, the width of the annual xylem increments was diminished. In both species, the typical structure of annual phloem increment was lost in the non-collapsed phloem and sclereids were very abundant in the collapsed phloem. InA. alba , the collapsed phloem was rich in swollen parenchyma cells containing blue-stained contents, while inP. abies , numerous large traumatic resin canals were conspicuous. The study showed that similar patterns of vascular tissue restoration exist inA. alba andP. abies in response to tree felling. However, there are certain species-specific peculiarities in the wood and phloem anatomical response, which might affect long-term stump functioning and survival. [ABSTRACT FROM AUTHOR]- Published
- 2024
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