Duration of cambial activity is determined by water availability while cambial stimulus is day-length dependent in a Neotropical evergreen species

Abstract

A B S T R A C TExperimental manipulations are essential for understanding the causal factors of plant growth and cambial activity. Here, we studied the potential effect of water availability and natural variation of day length and temperature on cambial activity in Cordiera concolor (Cham.) Kuntze, an evergreen tropical species. Experiments were conducted in a greenhouse using ninety one-year-old plants divided into two groups. Each group was observed for five weeks during two different times of the year (early spring and late summer). Plants were subjected to three distinct water regimes (waterlogging, field capacity and water deficit). Temperature and day length were recorded daily and stem samples were taken weekly during both sampling intervals. Anatomical procedures were used to describe the cambial activity per stem. Our results suggest that soil water content and its influence on cambial activity depend on the time of year, while cambial stimulus was positively related to day length, independent of the time of year. In early spring, cambial activity was stimulated by an increase of day length, regardless of water supply. In contrast, in late summer, cambial dormancy was delayed in waterlogged plants and advanced in plants subjected to a water deficit, followed by decreasing day length. Analyses of the wood anatomy showed that the marginal bands of axial parenchyma were initial. Our study highlights a more complex scenario of plant functioning and its causal factors in tropical systems.

Photoperiod drives cessation of wood formation in northern conifers

“…The most common constraint to the onset of wood formation is low temperature, which limits the initiation of new cambium cells. The temperature sensitivity gradually increases from winter to spring, and either an accumulation of chilling or an increase in day length interacts with temperature to initiate cell division in the cambium (Begum et al, 2018; Totti de Lara et al, 2017). Some recent studies have highlighted the crucial role of other external factors (e.g., water availability) in regulating spring xylogenesis, particularly in regions suffering from seasonal water deficit (Li et al, 2021; Ren et al, 2018; Ziaco et al, 2018).…”

Early Summer Temperature Variation Recorded by Earlywood Width in the Northern Boundary of Pinus taiwanensis Hayata in Central China and Its Linkages to the Indian and Pacific Oceans

“…The sixth IPCC research report showed that the global mean surface temperature has risen about 1 °C since 1900 and is expected to reach or exceed 1.5 °C from the perspective of mean temperature change in the next 20 years; thus, global warming had become fact [ 1 ]. Global warming causes changes in the structure and function of forest ecosystems and trees, and previous studies showed that tree xylem growth is controlled by climate factors, and climate change could lead to changes in tree-ring width by affecting the process of tree physiology and growth; hence, the data of tree rings can better record and reflect the current climate change information [ 2 , 3 ]. In order to improve the ability of predicting global climate change in the future, the PAGES (Past Global Changes) program proposed to study past climate change by using different proxy indicators (including tree ring, pollen, ice core, loess, lake sediment, coral, etc.)…”

Anatomia comparada do xilema secundário de espécies arbóreas do Cerrado

“…Algumas espécies decíduas e brevidecíduas apresentaram maior taxa de crescimento radial no início da estação chuvosa, com uma queda progressiva a partir deste período, enquanto espécies sempre-verdes demonstraram comportamento oposto, mostrando-se sensíveis às variações de pluviosidade durante o período úmido e apresentando maiores taxa de crescimento nos meses de maior precipitação (SARACENO, 2006). Em estudo realizado com a espécie sempre-verde Cordiera concolor observou-se que, independentemente da época do ano, a atividade cambial foi positivamente relacionada ao fotoperíodo, enquanto o teor de água no solo afetou a dormência cambial somente após a redução do fotoperíodo (final do verão) (LARA et al, 2017). As variações estruturais e funcionais da casca também podem estar associadas ao armazenamento e transporte de água, relacionadas principalmente às propriedades da casca interna.…”