Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.)
(1) Background: the cambium has seasonal activity, forming earlywood and early phloem with relatively wide conducting cells, which will function during the most favorable season, and latewood and late phloem with narrower conducting cells, which typically function during the less favorable season. H...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/14/5/920 |
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| author | Marcelo R. Pace Rafaella Dutra Carmen R. Marcati Veronica Angyalossy Ray F. Evert |
| author_facet | Marcelo R. Pace Rafaella Dutra Carmen R. Marcati Veronica Angyalossy Ray F. Evert |
| author_sort | Marcelo R. Pace |
| collection | DOAJ |
| description | (1) Background: the cambium has seasonal activity, forming earlywood and early phloem with relatively wide conducting cells, which will function during the most favorable season, and latewood and late phloem with narrower conducting cells, which typically function during the less favorable season. However, few studies have focused on when these two contrasting tissue types are formed in relation to climatic conditions. (2) Methods: the senior author of this paper made weekly collections for an entire year of four specimens per collection back in the 1960s, using traditional anatomical methods to study in detail what the cambium was producing progressively. (3) Results: annual growth rings are evident in both secondary xylem and secondary phloem. The cambium resumes activity in early April, with simultaneous formation of wood and secondary phloem. Both latewood and late phloem production are initiated in early June, the peak of the favorable season. The cambium ends its activity in early August. Phloem growth rings are marked by radially narrow sieve elements interspersed among a band of axial parenchyma with dark contents. Most specimens produce only one fiber band per season. This feature may be used as an indirect phloem growth ring marker. Wood growth rings are marked by very wide vessels and thick-walled, radially narrow fibers. (4) Conclusions: growth rings are evident in both secondary xylem and secondary phloem. The trees produce their latewood and late phloem long before the beginning of autumn, indicating that they prepare ahead of the selective regime, a phenomenon most likely dependent on the photoperiod. Living sieve elements are present yearlong. |
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| id | doaj.art-f4427b4230dd495e908541e8effb8f4c |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-11T03:44:15Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-f4427b4230dd495e908541e8effb8f4c2023-11-18T01:23:41ZengMDPI AGForests1999-49072023-04-0114592010.3390/f14050920Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.)Marcelo R. Pace0Rafaella Dutra1Carmen R. Marcati2Veronica Angyalossy3Ray F. Evert4Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Circuito Zona Deportiva s.n., Ciudad Universitaria, Mexico City 04510, MexicoDepartamento de Ciência Florestal, Solos e Ambiente, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Avenida Universitária 3780, Botucatu 18610-034, SP, BrazilDepartamento de Ciência Florestal, Solos e Ambiente, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Avenida Universitária 3780, Botucatu 18610-034, SP, BrazilDepartamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo 05508-090, SP, BrazilDepartment of Botany, University of Wisconsin in Madison, 430 Lincoln Drive, Madison, WI 53706-1381, USA(1) Background: the cambium has seasonal activity, forming earlywood and early phloem with relatively wide conducting cells, which will function during the most favorable season, and latewood and late phloem with narrower conducting cells, which typically function during the less favorable season. However, few studies have focused on when these two contrasting tissue types are formed in relation to climatic conditions. (2) Methods: the senior author of this paper made weekly collections for an entire year of four specimens per collection back in the 1960s, using traditional anatomical methods to study in detail what the cambium was producing progressively. (3) Results: annual growth rings are evident in both secondary xylem and secondary phloem. The cambium resumes activity in early April, with simultaneous formation of wood and secondary phloem. Both latewood and late phloem production are initiated in early June, the peak of the favorable season. The cambium ends its activity in early August. Phloem growth rings are marked by radially narrow sieve elements interspersed among a band of axial parenchyma with dark contents. Most specimens produce only one fiber band per season. This feature may be used as an indirect phloem growth ring marker. Wood growth rings are marked by very wide vessels and thick-walled, radially narrow fibers. (4) Conclusions: growth rings are evident in both secondary xylem and secondary phloem. The trees produce their latewood and late phloem long before the beginning of autumn, indicating that they prepare ahead of the selective regime, a phenomenon most likely dependent on the photoperiod. Living sieve elements are present yearlong.https://www.mdpi.com/1999-4907/14/5/920barkseasonality of cambial activityphloem growth rings |
| spellingShingle | Marcelo R. Pace Rafaella Dutra Carmen R. Marcati Veronica Angyalossy Ray F. Evert Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) Forests bark seasonality of cambial activity phloem growth rings |
| title | Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) |
| title_full | Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) |
| title_fullStr | Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) |
| title_full_unstemmed | Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) |
| title_short | Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (<i>Quercus alba</i> L.) |
| title_sort | seasonal cambial activity and formation of secondary phloem and xylem in white oaks i quercus alba i l |
| topic | bark seasonality of cambial activity phloem growth rings |
| url | https://www.mdpi.com/1999-4907/14/5/920 |
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