Seasonal Dynamics of Wood Formation in Pinus Halepensis from Dry and Semi-Arid Ecosystems in Spain

The seasonal dynamic s of cambial activity, wood formation , occurrence of false rings (FR), and tangential bands of resin canals (RC) were investigated in Pinus halepensis from three Mediterranean dry and semi-arid ecosystems in Spain. We collected intact tissues of phloem, cambium, and outer xylem at monthly intervals throughout 2004 from each time six trees at the three sites. Cell divisions in the cambium in all trees started before our first sampling in mid-March and ceased between November and December. Cambial activity was characterized by two maxima; one in spring and another in autumn. Trees still grew in summer but at a very low rate. The first solitary RC were formed in May or June and tangential bands ofRC in June or July. In general , tangential bands ofRC were observed in wider growth rings . The formation of tangential bands of RC seems to be induced by drought in the second half of the growing season . FR were formed as a result of cambial reactivation in autumn and were observed in growth rings that contained more than 50 cells in a radial row.It appears that summer drought and early autumn precipitation play an important role in false-ring formation.

Download Full-text

Origin of Intra-annual Density Fluctuations in a Semi-arid Area of Northwestern China

Frontiers in Plant Science ◽

10.3389/fpls.2021.777753 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jiani Gao ◽

Sergio Rossi ◽

Bao Yang

Keyword(s):

Cambial Activity ◽

Wood Formation ◽

Density Fluctuations ◽

Arid Ecosystems ◽

Wall Thickening ◽

Drought Event ◽

Cell Enlargement ◽

Xylem Formation ◽

June July ◽

Semi Arid

Intra-annual density fluctuation (IADF) is a structural modification of the tree ring in response to fluctuations in the weather. The expected changes in monsoon flow would lead to heterogeneous moisture conditions during the growing season and increase the occurrence of IADF in trees of the arid ecosystems of continental Asia. To reveal the timings and physiological mechanisms behind IADF formation, we monitored cambial activity and wood formation in Chinese pine (Pinus tabuliformis) during 2017–2019 at three sites in semi-arid China. We compared the dynamics of xylem formation under a drought event, testing the hypothesis that drought affects the process of cell enlargement and thus induces the production of IADF. Wood microcores collected weekly from April to October were used for anatomical analyses to estimate the timings of cambial activity, and the phases of enlargement, wall thickening, and lignification of the xylem. The first cells started enlargement from late April to early May. The last latewood cells completed differentiation in mid-September. Trees produced IADF in 2018. During that year, a drought in June limited cell production in the cambium, only 36% of the xylem cells being formed in IADF trees, compared to 68% in normal tree rings. IADF cells enlarged under drought in early July and started wall thickening during the rainfall events of late July. The drought restricted cell enlargement and affected wall thickening, resulting in narrow cells with wide walls. Cambium and cell enlargement recovered from the abundant rainfall, producing a new layer with large earlywood tracheids. IADF is a specific adaptation of trees to cope with water deficit events occurring during xylem formation. Our findings confirmed the hypothesis that the June-July drought induces latewood-like IADFs by limiting the process of cell enlargement in the xylem. Our finding suggests a higher occurrence of IADF in trees of arid and semi-arid climates of continental Asia if the changes to monsoon flows result in more frequent drought events during the earlywood formation in June.

Download Full-text

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

Botany ◽

10.1139/cjb-2014-0198 ◽

2015 ◽

Vol 93 (4) ◽

pp. 211-220 ◽

Cited By ~ 8

Author(s):

Arno Fritz das Neves Brandes ◽

Claudio Sergio Lisi ◽

Leonardo Davi S.A.B. da Silva ◽

Kishore S. Rajput ◽

Cláudia Franca Barros

Keyword(s):

Tree Species ◽

Secondary Xylem ◽

Cambial Activity ◽

Wood Formation ◽

Montane Forest ◽

Vascular Cambium ◽

Growth Rings ◽

Indirect Methods ◽

Annual Growth Rings ◽

Direct And Indirect Methods

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.

Download Full-text

Variations in carbon 14 content in tree rings during the last 30 years: application to wood dating

Canadian Journal of Forest Research ◽

10.1139/x90-033 ◽

1990 ◽

Vol 20 (2) ◽

pp. 241-244 ◽

Cited By ~ 2

Author(s):

Daniel Auclair ◽

Jacques Evin ◽

Loïc Pages

Keyword(s):

Confidence Interval ◽

Wood Formation ◽

Strongly Correlated ◽

Annual Rings ◽

Growth Rings ◽

Sharp Rise ◽

Carbon 14 ◽

False Rings ◽

Annual Growth Rings ◽

Nuclear Weapon Tests

Robiniapseudoacacia stem annual growth rings from 1958 to 1987 were analyzed for 14C content. The radioactivity of annual rings was found to be strongly correlated with 14C concentration in the atmosphere, which showed a very sharp rise until 1963 due to nuclear weapon tests followed by a regular decrease from then on. Taking into account seasonal variations in both atmospheric 14C concentration and CO2 assimilation slightly improved the relation between 14C in wood and the atmosphere. A predictive curve that gives the year of wood formation as a function of radioactivity with a 5% confidence interval is shown. These results can be used to analyze wood for which traditional analysis is impossible, for example, trees with false rings or missing rings, or wood from stumps or roots.

Download Full-text

Influence of Rainfall, Irrigation and Age on the Growth Periodicity and Wood Structure in Teak (Tectona Grandis)

IAWA Journal ◽

10.1163/22941932-90000678 ◽

1999 ◽

Vol 20 (2) ◽

pp. 181-192 ◽

Cited By ~ 37

Author(s):

P.B. Priya ◽

K.M. Bhat

Keyword(s):

Tectona Grandis ◽

Cambial Activity ◽

Growth Rings ◽

Peak Period ◽

Annual Cycles ◽

Cambial Reactivation ◽

Teak Wood ◽

June July ◽

Old Trees ◽

Growth Periodicity

Growth periodicity was followed for two consecutive annual cycles to reveal the pattern of wood fonnation in plantation-grown teak at three different localities in India. Rainfall and age were the two important factors that influenced cambial activity. Cambial reactivation occurred during March-April in both years. The pre-monsoon showers broke the cambial donnancy at all three localities. Almost a month's interval was observed between bud break and initiation of radial growth . Irrespective of age and locality, a peak period of cambial activity occurred during June-July. Dormancy began during October-December, depending on the age of the trees and locality. Juvenile trees and those grown in relatively high rainfall areas had a prolonged cambial activity and retained foliage throughout the year. They produced wider rings with higher proportions of latewood. Irrigation of 5-year-old trees led to the loss of typical ring porosity of teak wood; their first three growth rings were more or less diffuse-porous. This is attributed to uninterrupted cambial activity resulting in production of rather uniform-sized vessels.

Download Full-text

Long-Term Tree-Ring Response to Drought and Frost in Two Pinus halepensis Populations Growing under Contrasting Environmental Conditions in Peninsular Italy

Forests ◽

10.3390/f12030305 ◽

2021 ◽

Vol 12 (3) ◽

pp. 305

Author(s):

Alfredo Di Filippo ◽

Michele Baliva ◽

Michele Brunetti ◽

Luca Di Fiore

Keyword(s):

Tree Ring ◽

Environmental Conditions ◽

Pinus Halepensis ◽

Shoot Formation ◽

Cambial Activity ◽

Summer Drought ◽

Mountain Areas ◽

Multispectral Satellite Images ◽

Mediterranean Mountains

Pinus halepensis dominates coastal to mountain areas throughout the Mediterranean Basin. Its growth plasticity, based on polycyclic shoot formation and dynamic cambial activity, and tolerance to extreme drought and exceptional frosts, allows it to colonize a vast array of environments. We used tree-rings from codominant pines to compare lifespan, growth rates, age and size distribution in a typical coastal (i.e., prolonged drought, occasional low-intensity fires) vs. inland hilly (i.e., moister conditions, recurrent frosts) population. BAI trends, growth-limiting climate factors and tree-ring anatomical anomalies were analyzed considering the differences in climate and phenology obtained from multispectral satellite images. The species maximum lifespan was 100–125 years. Mortality was mainly due to fire on the coast, or heart-rot in the inland site. Populations differed in productivity, which was maintained over time despite recent warming. Site conditions affected the growing season dynamics, the control over ring formation by summer drought vs. winter cold and the frequency of anatomical anomalies. Recurrent frost rings, associated with temperatures below −10 °C, occurred only at the inland site. Pinus halepensis confirmed its remarkable growth plasticity to diverse and variable environmental conditions. Its ability to survive extreme events and sustain productivity confirmed its adaptability to climate change in coastal areas as well as on Mediterranean mountains.

Download Full-text

Cambial activity, wood formation and sapling survival of Pinus halepensis exposed to different irrigation regimes

Forest Ecology and Management ◽

10.1016/j.foreco.2011.07.013 ◽

2011 ◽

Vol 262 (8) ◽

pp. 1630-1638 ◽

Cited By ~ 53

Author(s):

Martin de Luis ◽

Klemen Novak ◽

José Raventós ◽

Jožica Gričar ◽

Peter Prislan ◽

...

Keyword(s):

Pinus Halepensis ◽

Cambial Activity ◽

Wood Formation ◽

Irrigation Regimes ◽

Sapling Survival

Download Full-text

SEASONAL VARIATION IN WOOD FORMATION OF CEDRELA FISSILIS (MELIACEAE)

IAWA Journal ◽

10.1163/22941932-90000149 ◽

2006 ◽

Vol 27 (2) ◽

pp. 199-211 ◽

Cited By ~ 34

Author(s):

Carmen Regina Marcati ◽

Veronica Angyalossy ◽

Ray Franklin Evert

Keyword(s):

Secondary Xylem ◽

Cambial Activity ◽

Wood Formation ◽

General Term ◽

Dry Season ◽

Climate Data ◽

Wet Season ◽

Growth Rings ◽

Dormant Period ◽

Xylem Formation

Cambial activity and periodicity of secondary xylem formation in Cedrela fissilis, a semi-ring-porous species, were studied. Wood samples were collected periodically from 1996 to 2000. The phenology was related to climate data of the region. The cambium has one active and one dormant period per year. The active period coincides with the wet season when trees leaf-out. The dormant period coincides with the dry season when trees lose their leaves. Growth rings are marked by parenchyma bands that begin to be formed, together with the small latewood vessels, just before the cambium becomes dormant at the beginning of the dry season. These bands are added to when the cambium reactivates in the wet season. At this time, the large earlywood vessels of the growth rings are also formed. As these bands consist of both terminal and initial parenchyma, we suggest the general term marginal bands be used to describe them. The growth layers vary in width among and within the trees.

Download Full-text

Effects of auxin-transport-inhibitor and defoliation on wood formation in locally-heated Abies homolepis

IAWA Journal ◽

10.1163/22941932-20170211 ◽

2018 ◽

Vol 39 (4) ◽

pp. 353-371 ◽

Cited By ~ 3

Author(s):

Md Hasnat Rahman ◽

Kayo Kudo ◽

Shahanara Begum ◽

Yusuke Yamagishi ◽

Takahiro Muraishi ◽

...

Keyword(s):

Auxin Transport ◽

Cambial Activity ◽

Wood Formation ◽

Limiting Factors ◽

Endogenous Factors ◽

Continuous Formation ◽

Transport Inhibitor ◽

Cambial Reactivation ◽

Abies Homolepis ◽

Auxin Transport Inhibitor

ABSTRACTTo understand the precise process of wood formation, it is necessary to identify the factors that regulate cambial activity and development of cambial derivatives. Here, we investigated the combined effects of localized-heating and auxin on cambial reactivation and the formation of earlywood tracheids in seedlings of the evergreen coniferAbies homolepisin winter. Three treatments were applied, namely heating (artificial increase in temperature 20–22 °C), heating-plus-auxin transport inhibitor N-(1-naphthyl) phthalamic acid (NPA) and heating-plus-defoliation (removal of needles and buds), with an approximate control, for investigations of cambial activity by light microscopy. After one week of heating, cambial reactivation occurred in the heating, heating-plus-NPA and heating-plus-defoliation treatments. In untreated controls, cambial reactivation occurred later than in heated stems. Earlywood tracheids were formed after three and six weeks of heating in the heating and heating-plus-NPA treatments, respectively. No tracheids were formed after eight weeks of heating in heated-defoliated seedlings. Numbers of new tracheids were reduced in heated stems by NPA. Our results suggest that an increase in the temperature of the stem is one of the most important limiting factors in cambial reactivation, which is independent of needles and buds and of the polar transport of auxin from apical sources. However, after cambial reactivation, initiation and continuous formation of earlywood tracheids require basipetally transported auxin and other endogenous factors originating in mature needles and buds.

Download Full-text

Age, climate and intra-annual density fluctuations in Pinus halepensis in Spain

IAWA Journal ◽

10.1163/22941932-00000037 ◽

2013 ◽

Vol 34 (4) ◽

pp. 459-474 ◽

Cited By ~ 37

Author(s):

Klemen Novak ◽

Miguel Angel Saz Sánchez ◽

Katarina Čufar ◽

Josep Raventós ◽

Martin de Luis

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Pinus Halepensis ◽

Climatic Factors ◽

Late Summer ◽

Density Fluctuations ◽

Temperate Climate ◽

Summer Drought ◽

Cambial Age ◽

Cambial Reactivation

Intra-annual density fluctuations (IADFs) in tree rings of Aleppo pine (Pinus halepensis) are considered to be among the most promising wood anatomical features in dendrochronological studies. They provide environmental information in addition to those obtained from tree-ring widths. We used a network of 35 sites in Spain, ranging from nearly desert to temperate climate. We analysed tree-ring series of 529 trees to study IADF frequencies, and their dependence on climatic factors and cambial age. The results showed that IADF frequency is age dependent, with its maximum at the cambial age of 27 years (evaluated at breast height). The frequencies varied across the network and at different sites we recorded that 0.3% to 33% of the analysed tree rings contained IADFs. They were more frequent where and when the temperatures were higher, summer drought was intense and autumn was the main precipitation season. IADF formation was particularly related to high minimum temperatures and wet conditions in late summer and autumn. These results suggest that IADF formation is not related to stressful conditions during summer but to favourable conditions during autumn. These conditions promote cambial reactivation and consequently formation of wider tree rings.

Download Full-text

MISSING AND DARK RINGS ASSOCIATED WITH DROUGHT IN PINUS HALEPENSIS

IAWA Journal ◽

10.1163/22941932-20160133 ◽

2016 ◽

Vol 37 (2) ◽

pp. 260-274 ◽

Cited By ~ 16

Author(s):

Klemen Novak ◽

Martin De Luis ◽

Jožica Gričar ◽

Peter Prislan ◽

Maks Merela ◽

...

Keyword(s):

Annual Ring ◽

Pinus Halepensis ◽

Growing Season ◽

Wood Formation ◽

Vascular Cambium ◽

Primary Study ◽

Average Width ◽

Dendrochronological Analysis ◽

Cambial Reactivation ◽

Narrow Ring

The responses of the vascular cambium and tracheid differentiation to extreme drought in Aleppo pine (Pinus halepensis Mill.) were investigated. The research focused on the drought year of 2005, in the primary study area at Maigmo (MAI) in southeastern Spain, with comparisons in Jarafuel (JAL) and Guardamar (GUA). The climate in this region is typically warm and dry with hot summers. Wood formation throughout the 2005 growing season was studied in transverse microtome sections and integrated with a retrospective dendrochronological analysis of crossdated increment cores collected in 2009. For most anatomical sections collected throughout the growing season at MAI, the vascular cambium appeared to be dormant as indicated by the low number of cells per radial file. Occasionally, immature xylem derivatives were observed during the growing season but without production of an annual ring. In increment cores collected at MAI, the 2005 position in the annual ring series contained either a narrow ring of both earlywood and latewood (47% of samples), a narrow ring of apparent latewood with no earlywood (13%), or a missing ring (50%). We introduce the term “dark ring” to refer to those annual rings of apparent latewood with no earlywood. For trees at JAL, the 2005 ring had below-average width and contained both earlywood and latewood. At GUA, the trees produced the widest 2005 ring of all three sites and mainly contained an intra-annual density fluctuation (IADF). The IADF was formed after cambial reactivation in the autumn. Although dark rings, IADFs, and especially missing rings complicate dendrochronological analysis, these anatomical features may provide an additional proxy record from which to infer climate variability and change in the past.

Download Full-text