Seasonal Cambial Activity Research Articles

Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (Quercus alba 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. 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.

Intra-annual radial growth of Garuga floribunda in tropical seasonal rain forest and its response to environmental factors in Xishuangbanna, Southwest China

We examined the seasonal growth dynamics of a deciduous tree species Garuga floribunda in the tropical seasonal rain forest in Xishuangbanna and monitored the stem radial growth with both high resolution dendrometer and microcoring methods. Combining with the monitoring of non-structural carbohydrates (NSCs) in stem and environmental factors, we analyzed the eco-physiological drivers underlying the seasonal cambial activity and radial growth dynamics. The results of high reso-lution dendrometer method showed that the growth of G. floribunda began at the end of May (day of year, DOY: 149.3±7.2) and ended at the end of August (DOY: 241.0±14.7) in 2020, the annual total radial growth was 3.12 mm, and the maximum growth rate was 0.04 mm·d-1. Based on the microcoring methods, we found that xylem cell enlarging started from March 9th (69.2±6.2) and cell wall thickening ended on September 19th (DOY: 262.8±2.8). The cumulative xylem radial growth was 1.76 mm, and the maximum growth rate was 0.009 mm·d-1. The daily radial growth rate of G. floribunda was significantly and positively correlated with precipitation, relative humidity, daily minimum air temperature, soil moisture and temperature at the depth of 20 cm, and was negatively correlated with daily maximum air temperature, vapor pressure deficit, maximum wind speed, and water vapor pressure. The starch and soluble sugar contents in the sapwood of G. floribunda were relatively higher before the growing season. The starch content was lowest in the end of March, while the content of soluble sugars was lowest in middle of May. At the end of the growing season, the contents of starch and soluble sugar in G. floribunda peaked in the middle of October and the end of December, respectively.

Cambial activity in dry and rainy season on branches from woody species growing in Brazilian Cerrado

Seasonal cambial activity was investigated in one- to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southern Brazil. Relationships between cambial activity and environmental factors (precipitation, temperature, day length) and leaf production were tested using generalized linear mixed model. Regardless the plant habit and leaf shedding patterns, cambial activity (about 5 months) corresponded to the core of the rainy season (when at least 66% of the annual precipitation had been reached), even though there was some delay or advance in the timing of cambial activity depending on the branch age or species. Cambial activity began in the dry season and ceased before the end of rainy season. Although cambial activity has been positively correlated with day length, precipitation, temperature, and budding for all species, day length, among the assessed factors, seems to be the best predictor of onset and cessation of cambial activity in the branch modules of cerrado species.

Seasonal cambial activity and wood formation in trees and lianas of Leguminosae growing in the Atlantic Forest: a comparative study

Cambial activity and the formation of secondary xylem were investigated in the main stem of three arboreal leguminous species and one liana. To compare the seasonal vascular cambium behavior of these species, two methods were concurrently applied: induction of injury in the vascular cambium and anatomical analysis of the vascular cambium and adjacent zones (differentiation zone). One tree species, Pseudopiptadenia contorta (DC.) G.P.Lewis & M.P.Lima, was sampled in three forest formations: alluvial, submontane, and montane. Two more tree species, Apuleia leiocarpa (Vogel) J.F.Macbr. and Pseudopiptadenia leptostachya (Benth.) Rauschert, were sampled in submontane and montane forest, respectively. Dalbergia frutescens (Vell.) Britton var. frutescens, a liana, was sampled in montane forest. All species investigated showed distinctive formation of annual growth rings. Reactivation of the vascular cambium was observed at the end of spring, and it remained active during the summer. Thereafter, cambial activity either ceased or declined dramatically at the end of autumn. Similar to the tree species studied, cambial activity in D. frutescens var. frutescens showed similar seasonal cambial activity throughout the year. Based on both direct and indirect methods, our results showed that cambial activity and wood formation only occurred during the rainy season, suggesting the potential of these species for use in dendrochronological studies.

Relations between water balance, wood traits and phenological behavior of tree species from a tropical dry forest in Costa Rica--a multifactorial study

Drought tolerance is a key factor for the establishment and survival of tree species in tropical ecosystems. Specific mechanisms of drought resistance can be grouped into four functional ecotypes based on differences in leaf fall behavior: deciduous, brevi-deciduous, stem succulent and evergreen. To identify the key factors influencing phenology and cambial activity and thus drought tolerance, we tested the stomatal conductance, leaf water potential and stable carbon isotopes in the leaves and wood of 12 species from a tropical dry forest in Costa Rica. With wood anatomical techniques, we further studied seasonal cambial activity and a suite of wood traits related to water transport for each of the functional ecotypes. Using a principal component analysis, we identified two groups of variables that can be related to (i) hydraulic conductivity and (ii) control of transpiration and water loss. Hydraulic conductivity is controlled by vessel size as the limiting variable, water potential as the driving force and wood density as the stabilizing factor of the anatomical structure of an effective water transport system. Stomatal control plays a major role in terms of water loss or saving and is the dominant factor for differences in phenological behavior. Stem succulent species in particular developed a rarely identified but highly effective strategy against drought stress, which makes it a successful pioneer species in tropical dry forests.

Seasonal cambial activity of five tropical tree species in central Thailand

The seasonal cambial activity of five tropical tree species was investigated at Khao Yai National Park. The species studied were Tetrameles nudiflora, Magnolia baillonii, Canarium euphyllum Kur, Toona ciliata, and Spondias axillaris. Cambial activity was quantified by counting layers of undifferentiated cells in the cambium zone from wood anatomical micro sections prepared from wood samples collected in monthly intervals from July 2010 to June 2011. The relationship between cambial activity and climatic factors was investigated by using Pearson’s correlation. The growth dynamics of five studied species differed considerably. The cambium of Tetrameles nudiflora and Magnolia baillonii was most active when rainfall reached its maximum amount in June (mid rainy season), whereas the cambium of Canarium euphyllum, Toona ciliata, and Spondias axillaris was most active in March during the transition from the dry to the wet season.

Cambial activity of Pinus elliottii var. densa reveals influence of seasonal insolation on growth dynamics in the Florida Keys

We determined the temporal and seasonal dynamics of intra-annual cell formation of south Florida slash pine (Pinus elliottii Engelm. var. densa Little & Dor.), the southernmost native pine in the United States and the foundation species of globally endangered pine rockland ecosystems. To assess intra-annual cambial activity and identify possible relationships between cell production and climatic factors, wood micro-cores were extracted monthly from six trees during the period March 2010 to March 2011. The results confirmed annual growth ring formation in P. elliottii var. densa and indicated that its growing season extends from February to December, with a short period of dormancy that varied little between individuals. Within the growing season, earlywood cells were produced from February to July, latewood cells pro- duced from July to December, and intra-annual density fluctuations (IADFs) occurred in the growth rings of four of six trees between July and August. A principal component analysis indicated a homogeneous response of cambial activity among trees to site-specific climatic factors. The first principal component axis explained 71 % of the total variance in cell production during the study period. Our results indicated that the dynamics of seasonal cambial activity of P. elliottii var. densa are controlled by solar radiation (r = 0.51, p \ 0.10) in the Florida Keys. The nature of our data allow us to only speculate on the eco- physiological processes responsible for IADFs in P. elli- ottii var. densa, and additional research is needed to better understand the relationship between their formation and the environment in the Lower Florida Keys.

Environmental modulation of the seasonal cambial activity in Prosopis flexuosa DC trees from the Monte woodlands of Argentina

The rhythm of cambial activity and its relationship with precipitation, temperature and phenology was analyzed in Prosopis flexuosa trees from the xerophytic woodlands of western Argentina. Periodic tree growth measurements made in a P. flexuosa-dominated stand between 2005 and 2008 showed that earlywood tree-ring development starts in the early spring (October), when young vegetative buds begin expansion and completes its formation at the end of November when fruits are almost ripe. The development of the tree-ring latewood is completed in early January (the middle of summer). Redundancy Analysis suggests that cumulative daily rainfall 4–6 days prior to core sampling significantly influences cambial growth, while temperatures 0–3 days preceding core sampling show the most significant effect on growth. An Artificial Neural Network analysis suggests a positive, monotonic effect of rainfall on cambial growth, whereas temperature shows a modal effect on growth with a peak at 18–20 °C. The results provide important new information about the eco-physiology of P. flexuosa trees in the Monte region of Argentina, and indicate that this species responds rapidly to changes in rainfall and temperatures during the growing season.

Cambial growth dynamics and climatic control of different tree life forms in tropical mountain forest in Ethiopia

Munessa Forest is a mountain forest in south-eastern Ethiopia experiencing seasonal rainfall variation. We investigated seasonal cambial activity and dormancy from increment rates of four different tree species belonging to varying life forms, namely, evergreen native conifer (Podocarpus falcatus), evergreen introduced conifer (Pinus patula), evergreen broadleaved tree (Prunus africana) and deciduous broadleaved tree (Celtis africana). Measurements of stem radius fluctuations were registered with the help of high-resolution electronic dendrometers. Daily amplitudes of stem diameter variations and daily and monthly net growth rates were determined and related to climatic variables measured at local climate stations. Thin sections of wood collected with a microcorer every 3–6 weeks allowed a visual control of newly formed wood cells during consecutive time intervals. Lack of water availability during the long dry season induced cambial dormancy of 5–7 months depending on life forms. After the onset of the short rainy season, stem swelling started quite synchronously with a variation of only single days in all studied species. Evergreen tree species were able to initiate wood formation during the short rainy season, whereas growth in the deciduous broadleaved species started in the long rainy season. The acquired data provide a basis for delineating the species-specific growth boundaries and the duration of the cambial growing season.

Cambial Activity and Wood Anatomy in Prosopis Spicigera (Mimosaceae) Affected by Combined air Pollutants

Seasonal cambial activity and xylem anatomy were studied in Prosopis spicigera Linn. (Mimosaceae) growing under the influence of combined air pollutants. Cambial cell division and differentiation of secondary xylem began in April, reached a peak in July–August and ceased in October in trees (normal) growing in a relatively unpolluted locality. In contrast, in trees (affected) growing near a fertilizer complex, the initiation of cambial activity was delayed by one month and the cambium ceased to divide in September. Considerable variations were noticed in the structure and arrangement of xylem derivatives between affected and normal trees. The vessel lumen diameter was reduced and vessel frequency was significantly higher in the affected trees. Axial parenchyma was aliform to confluent in normal trees compared to mainly vasicentric parenchyma with heavy accumulation of tannin contents in affected trees. Cambial activity and xylem development did not show any correlation with the phenology of affected trees.

Seasonal development of secondary xylem and phloem in Schizolobium parahyba (Vell.) Blake (Leguminosae: Caesalpinioideae)

The cambial activity and periodicity of secondary xylem and phloem formation have been less studied in tropical tree species than in temperate ones. This paper describes the relationship between seasonal cambial activity, xylem and phloem development, and phenology in Schizolobium parahyba, a fast growing semideciduous seasonal forest tree from southeastern Brazil. From 2002 to 2003, wood samples were collected periodically and phenology and climate were recorded monthly in the same period. S. parahyba forms annual growth increments in wood, delimited by narrow initial parenchyma bands. The reduction of the cambial activity to a minimum correlates to the dry season and leaf fall. The higher cambial activity correlates to the wet season and the presence of mature leaves. In phloem, a larger conductive region was observed in the wet season, when the trees were in full foliage. The secondary phloem did not exhibit any incremental zone marker; however, we found that the axial parenchyma tends to form irregular bands.

Seasonal cambial activity and tree-ring formation of Pinus merkusii and Pinus kesiya in Northern Thailand in dependence on climate

This study is aimed at characterizing the cambial dynamics and its dependence on climate of two pine species native to Thailand, Pinus merkusii and Pinus kesiya and at describing their climatic response over 148 years. The samples for cambial activity analysis were taken monthly from March 2000 to February 2001, and the cambial activity was determined by counting the number of undifferentiated cell layers between mature xylem and phloem in transverse sections. Statistical analysis was done using Pearson's correlation. For the dendroclimatological analysis, samples were collected from the same sites in March 2004, and dendroclimatological standard techniques were applied. The results indicated that soil moisture influenced the cambial activity of P. merkusii and P. kesiya, however that rainfall and temperature had no significant effect on the cambial activity of both species. The response function described the relationship between tree-ring widths indices and monthly rainfall and temperature and revealed that the growth of P. merkusii at Hung Boung depended positively from rainfall in May. P. merkusii at Bao Kaew, however, had a positive correlation with rainfall from previous November to current July, whereas temperature in the preceding autumn and winter should be above-average and in the current spring and summer should be below-average. P. kesiya at Nong Kra Ting showed a slightly positive correlation with rainfall from February to June, but a strong dependence on rainfall in September. It can be concluded that the study of cambial activity could support our understanding of intra-annual variations and duration of tree-ring development, whereas the response function could help explain the average response of tree-growth to climate.

Relationship between seasonal cambial activity, development of xylem and phenology in Azadirachta indica growing in different forests of Gujarat State

Seasonal cycle of cambial activity was compared among the trees of Azadirachta indica growing in Moist Deciduous (MDF), Dry Deciduous (DDF) and Scrub land Forest (SF) of Gujarat State. Radial growth occurred in two growth flushes in MDF and DDF. Cambial cell divisions in MDF started in February and June resulting maximal radial growth in August-September when the rains were heavy and ceased in January and May during the drier part of the year. In DDF the first flush of growth commenced in January with maximal xylem development in April and ceased in May. The second flush of cambial activity began in June with the arrival of rains, reached peak in October and ceased in December. Cambium was active throughout the year in SF and attained its peak activity thrice i.e. in February, July and October. With complete maturation of leaves in November, the cell divisions were rather slow in MDF and SF whereas no divisions were encountered in DDF. Cambial rays exhibited large intercellular spaces during drier months in all the three fo- rests. Seasonal behavior of vascular cambium was discussed in relation to phenology and local climatic conditions.

Kinetics of Tracheid Differentiation in Douglas-fir

Seasonal cambial activity and the differentiation of tracheids were studied at five stem levels in three crown classes of Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir). Rates and durations of tracheid expansion and secondary wall deposition were computed. Seasonal changes in radial diameter of cells were attributable both to changes in duration and rate of cell expansion. Seasonal changes in cell wall area were determined by changes in duration of wall deposition. Durations of cell expansion and wall deposition showed a marked trend to increase down the stem, whereas rates of tracheid differentiation showed no clear axial trend. Axial trends in cell dimensions, particularly cell wall area, were mainly determined by durations of differentiation. Rates of cell wall thickening varied among crown classes suggesting that assimilate status is important in determining this process.

Seasonal Cambial Activity for Pentaclethra, Goelthalsia, and Carapa Trees in a Costa Rican Lowland Forest

At the La Selva Biological Station, Costa Rica, dendrometer bands were read monthly for a year to monitor the seasonality and rate of girth increment for three common tree species: Pentaclethra macroloba (Mimosaceae), Goethalsia meiantha (Tiliaceae), and Carapa guianensis (Meliaceae). Annual diameter increment varied with tree size but was greatest for Goelthalsia (1.26 cm/yr), least for Carapa (0.04-0.34 cm/yr), and intermediate for Pentaclethra (0.20-1.06 cm/yr). Cambial activity for Pentaclethra was greatest during drier months (December to April), the only months when Pentaclethra was not in flower or fruit. In contrast, Goelthalsia and Carapa had less cambial activity during drier months (April and May), the time of leaf flushing for these species. Greater growth during the drier months, a characteristic not shared by relatively common Goelthalsia and Carapa trees, may provide a competitive advantage for Pentaclethra and help explain its abundance at La Selva. PENTACLETHRA MACROLOBA (Willd.) Kuntze (Mimosaceae) is the dominant tree species in all three of the major primary forest types of the La Selva Biological Station, Costa Rica. The importance values for Pentaclethra in these forests range from 18 to 23 percent (Hartshorn 1983a). For Pentaclethra to exert this degree of dominance in a speciesrich, Neotropical lowland suggests that this species competes well with over 450 tree species also native to La Selva (30-135 m elevation). Hartshorn (1983b) attributed the success of Pentaclethra to: (1) excellent seedling establishment in the absence of serious seed predation (toxic seed); (2) tolerance of relatively infertile soils that are probably restrictive to potentially competing species; (3) well-distributed and abundant rainfall that enables a swamp species, such as Pentaclethra, to extend to the ridgetops; and (4) shade tolerance that enables Pentaclethra to survive and even grow in the dense primary forest understory. In addition to these characteristics, Grime and Hunt (1975) suggested that dominance by one species is sometimes explained by differences in timing and rate of growth between the community's dominant and competing species. Also, Pentaclethra's water utilization patterns, evidenced by times of tree growth, may be different from those of competing species, as suggested for different tree species in a North American forest (Bunce et al. 1977). To examine this possibility at La Selva, the seasonal girth increment of the dominant Pentaclethra was compared with the girth increments of Goelthalsia meiantha (D. Sm.) Burret (Tiliaceae), a common gap-phase and secondgrowth species, and Carapa guianensis Aubl. (Meliaceae), a codominant, shade-tolerant, swamp species. MATERIALS AND METHODS Study areas were the 4-ha permanent inventory plots I and II at La Selva (Hartshorn 1983a). From 88 tree species in plot I, Pentaclethra is the dominant (importance value of 23%) and Goelthalsia is sixth in importance value at 2.55 percent. From 115 tree species in Plot II, Pentaclethra and Carapa are codominants (importance values of 18.1 and 11.3%, respectively). Plot I soil is fairly well-drained, alluvial material of the La Selva soil series, a dominant soil type in the area. Plot II is also on old alluvium, but has more poorly drained soils of the Swampo series (Bourgeois et al. 1972). Mean annual rainfall at La Selva is 3991 ? 748 mm (N = 22). Although nearly all canopy trees are in leaf throughout the year, the driest months of March and April are associated with maximum leaf drop and leaf flushing. A total of 14 Pentaclethra, 6 Carapa, and 3 Goelthalsia trees were selected for study. In Plot I, 3 large Pentaclethra trees (40-70 cm DBH), 8 small Pentaclethra trees (5-40 cm DBH), and 3 small Goelthalsia trees (1015 cm DBH) were banded. In Plot II, 3 Pentaclethra trees (30-40 cm DBH), 4 small Carapa trees (5-20 cm DBH), and 2 larger Carapa trees (30-45 cm DBH) were banded. All smaller trees (<25 cm DBH) were in recent treefall gaps, but their crowns were shaded most of the day by canopy trees. At least a portion of the crown of each larger individual reached to the main canopy. In September 1976 aluminum dendrometer bands, similar to those described by Woodman (1980), were installed on each of the 23 study trees. Bands were secured on tree boles at a height of 1.3 m by stainless steel expansion springs. Increments in girth were recorded for 13 months (near the beginning of each month) by reading vernier scales on each band. The initial interval reading I Received 14 October 1985, revision accepted 8 May 1986. BIOTROPICA 19(4): 357-36

Seasonal cambial activity and xylem development in Pinuscontorta in relation to endogenous indol-3-yl-acetic and (S)-abscisic acid levels

Seasonal cambial activity and xylem development were monitored anatomically at several main-stem positions in 20-year-old Pinuscontorta Dougl. Gas chromatography – mass spectrometry and electron-capture gas-chromatography quantifications of endogenous indol-3-yl-acetic acid (IAA) and (S)-abscisic acid (ABA), respectively, were made in these same tissues. In addition, IAA and ABA were measured in shoot apices, growing needles, and mature needles. Cambial reactivation occurred several weeks before budbreak at the base of the living crown, and it occurred only slightly before budbreak in younger cambia. Neither an acropetal nor a basipetal progression of reactivation were found. In contrast, early-wood development commenced in foliated stem locations well before commencing in nonfoliated regions. IAA and ABA levels in the cambial region increased, but little, immediately before cambial reactivation. IAA levels in extending apices, extending needle bases, and cambia reached maxima in midsummer. Cambial IAA levels remained high and ABA levels declined after both shoot and needle extension were complete. IAA levels in cambia were highest in the main stem near the crown base at all times; ABA levels varied little throughout the season. Following autumn inactivation of the cambium, IAA levels decreased and tracheids with narrow radial diameters differentiated at this time. ABA levels showed no significant increase as shoots, needles, and cambium ceased growing.

Certain seasonal changes in balsam fir cambium and its derivatives

The seasonal cambial activity of balsam fir producing normal and compression wood was observed. Samples were taken throughout one growing season. Activity was initiated in normal wood with the precocious development of one sieve cell per file 2 weeks before activity was initiated in compression wood with the formation of one new sieve cell per file. Deactivation dates in normal and compression wood were the same. Dating of the phloem adjacent to normal wood can be carried out using crushed sieve cells or an annually formed band of tannin filled parenchyma whereas adjacent to compression wood, only crushed sieve cells can be used. The maximum cambial zone widths in normal and compression wood were 15 and 16 cells, respectively. The final xylem to phloem ratio in normal wood was 14:1 while in compression wood it was 21:1. Time required for development of tracheids was examined throughout the growing season. Growth trends for the radial growth and differentiation phases were studied in both normal and compression wood. Tracheid development in normal wood took between 14 and 33 days while in compression wood it varied between 5 and 49 days.

L'Attività Cambiale in Piante diFagus SylvaticaL. Cresciute a Diverse Esposizioni Sull'Altipiano del Cansiglio (Prealpi Venete)

Abstract Cambial activity in beech trees grown at different exposures on the Cansiglio Plateau. — The seasonal cambial activity in beech trees at North and South exposures of the Cansiglio Plateau is rather short-lasting and the whole wood ring is formed from June to August. Phloem differentiation starts in April when new phloem cells are formed from the outer 2–3 rows of cambial cells. It is difficult to fix the end of cambial activity; on the contrary it is possible to establish that cambial activity starts in spring, more than 2 weeks earlier at south, in the second half of April. This anticipation is discussed in correlation with microclimatic factors. Cell differentiation lasts long after cambial activity has ceased in summer, prosecuting as late as November-December, wood lignification is under exposure influence; it starts and ends earlier at North, still without reaching such a high intensity as at south. Differentiating processes in south exposed trees, although proceeding slowlier, finally reach...