Parenchyma Bands Research Articles

Climate/growth relationships of Brachystegia spiciformis from the miombo woodland in south central Africa

Abstract We present five Brachystegia spiciformis Benth. (BrSp) tree-ring chronologies from the seasonally dry miombo woodland in south central Africa. Between 9 and 34 stem discs were collected from three dry and two wet miombo sites. All samples showed distinct growth rings, which were marked by terminal parenchyma bands. Site chronologies varied in length between 43 and 149 years. An increase in the number of growth ring anomalies in older trees, however, resulted in an increase in dating error and a decrease in between-tree correlations with increase in the chronology length. Annual precipitation variability accounted for some 28% of the common variance in the BrSp chronologies and we found no difference in climate sensitivity between wet and dry miombo sites. The influence of climate, and of precipitation in particular, on tree growth was strongest at the core of the rainy season (December–February). This is also the time of the year when ENSO peaks in amplitude and ENSO effects on precipitation variability in southern Africa are the strongest. We found a negative response of tree growth to ENSO throughout most of the growth year, suggesting that the development of longer chronologies from the miombo region would allow for the investigation of temporal ENSO variability. A spatial extension of the miombo tree-ring network should therefore focus on regions where ENSO effects are the strongest (e.g., southeastern Africa).

Developmental and structural features of secretory canals in root and shoot wood of Copaifera langsdorffii Desf. (Leguminosae–Caesalpinioideae)

Copaifera langsdorffii Desf., popularly known as copaiba, is an oleoresin-producing tree has been overexploited in Brazil by the pharmaceutical, cosmetic and varnish industries. Despite the long history of the use of this species, the structural knowledge on the resin-producing sites remains inadequate and is limited to the trunk. The aim of this study was to describe the origin, structure and developmental features of secretory spaces present in shoot and root wood of C. langsdorffii, based on the usual techniques of wood anatomy studies. Both root and shoot wood present secretory canals distributed along the marginal parenchyma bands which delimit growth layers. Secretory canals are constituted by a locally biseriate epithelium and lume that contains terpenes. They are arisen in the cambial zone from fusiform cambial initial cells and, eventually, ray initials. The origin of lumen is schizogenous. The epithelial cells have meristematic potential and are responsible for the locally biseriate epithelium. Mature secretory canals are wider and are separated between themselves only by a row of radial cells. The fusion of these adjacent secretory canals is frequent and results from the radial cell collapse. The finding of an interconnected system of resin canals in C. langsdorffii might be of value in terms of sustainable extraction of the resin and realistically assess its sustainable harvest potential.

Number of Cells in Xylem, Phloem and Dormant Cambium in Silver Fir (Abies Alba), in Trees of Different Vitality

We investigated the anatomical structure of phloem and xylem growth rings as well as the dormant cambium in relation to vitality in 81 adult silver fir trees (Abies alba Mill.). Specifically, we investigated the number of cells produced in the current phloem growth ring (PR), xylem growth ring (XR) and their ratio, the number of cells in the dormant cambium (CC), and the structure of the PR, which included characterisation of the early phloem (EP), the late phloem (LP), and the presence, absence, and continuity of tangential bands of axial parenchyma (AP). EP was relatively stable with respect to number and types of cells as PR width changed, but LP was quite variable. The CC of more vital trees produced more xylem than phloem cells. The ratio of XR to PR number decreased with decreasing vitality of trees and in the most severely affected trees (4% of the study group), more cells were formed in the PR than in the XR. The number of cells in phloem, xylem and dormant cambium is positively correlated. The use of width and structure of phloem and the ratios between PR, XR and CC can provide information on tree conditions and, consequently, can be a useful tool for forest management.

Suppression of 4-coumarate-CoA ligase in the coniferous gymnosperm Pinus radiata.

Severe suppression of 4-coumarate-coenzyme A ligase (4CL) in the coniferous gymnosperm Pinus radiata substantially affected plant phenotype and resulted in dwarfed plants with a "bonsai tree-like" appearance. Microscopic analyses of stem sections from 2-year-old plants revealed substantial morphological changes in both wood and bark tissues. This included the formation of weakly lignified tracheids that displayed signs of collapse and the development of circumferential bands of axial parenchyma. Acetyl bromide-soluble lignin assays and proton nuclear magnetic resonance studies revealed lignin reductions of 36% to 50% in the most severely affected transgenic plants. Two-dimensional nuclear magnetic resonance and pyrolysis-gas chromatography-mass spectrometry studies indicated that lignin reductions were mainly due to depletion of guaiacyl but not p-hydroxyphenyl lignin. 4CL silencing also caused modifications in the lignin interunit linkage distribution, including elevated beta-aryl ether (beta-O-4 unit) and spirodienone (beta-1) levels, accompanied by lower phenylcoumaran (beta-5), resinol (beta-beta), and dibenzodioxocin (5-5/beta-O-4) levels. A sharp depletion in the level of saturated (dihydroconiferyl alcohol) end groups was also observed. Severe suppression of 4CL also affected carbohydrate metabolism. Most obvious was an up to approximately 2-fold increase in galactose content in wood from transgenic plants due to increased compression wood formation. The molecular, anatomical, and analytical data verified that the isolated 4CL clone is associated with lignin biosynthesis and illustrated that 4CL silencing leads to complex, often surprising, physiological and morphological changes in P. radiata.

Climate–growth relationships of the dominant tree species from semi-arid savanna woodland in Ethiopia

Long-term climate–growth relationships, were examined in tree rings of four co-occurring tree species from semi-arid Acacia savanna woodlands in Ethiopia. The main purpose of the study was to prove the presence of annual tree rings, evaluate the relationship between radial growth and climate parameters, and evaluate the association of El Niño and drought years in Ethiopia. The results showed that all species studied form distinct growth boundaries, though differences in distinctiveness were revealed among the species. Tree rings of the evergreen Balanites aegyptiaca were separated by vessels surrounding a thin parenchyma band and the growth boundary of the deciduous acacias was characterized by thin parenchyma bands. The mean annual diameter increment ranged from 3.6 to 5.0 mm. Acacia senegal and Acacia seyal showed more enhanced growth than Acacia tortilis and B. aegyptiaca. High positive correlations were found between the tree-ring width chronologies and precipitation data, and all species showed similar response to external climate forcing, which supports the formation of one tree-ring per year. Strong declines in tree-ring width correlated remarkably well with past El Niño Southern Oscillation (ENSO) events and drought/famine periods in Ethiopia. Spectral analysis of the master tree-ring chronology indicated occurrences of periodic drought events, which fall within the spectral peak equivalent to 2–8 years. Our results proved the strong linkage between tree-ring chronologies and climate, which sheds light on the potential of dendrochronological studies developing in Ethiopia. The outcome of this study has important implications for paleoclimatic reconstructions and in restoration of degraded lands.

Wood Anatomical Characteristics and Chemical Composition Of Prosopis Laevigata Grown in the Northeast of Mexico

Structural heartwood characteristics for Prosopis laevigata (Humb. & Bonpl. ex Willd.) M.C. Johnst., including a histometrical evaluation, were obtained by light microscopy coupled with a digitised image analysis system. The growth ring boundaries of the semi-ring-porous or diffuseporous wood are often marked by a marginal parenchyma band. Average fibre length is 975 μm, the fibres are thick-walled with a single cell wall thickness of 13 μm on average. Average diameter of the vessels which are arranged in non-specific patterns differs significantly between earlywood (116 μm) and latewood (44 μm). The topochemical distribution of lignin and phenolic deposits in the tissue was investigated by means of scanning UV microspectrophotometry (UMSP). Thereby, in heartwood tissue the deposition of extractives in vessels, pit canals, parenchyma cells, fibre lumina and partly also in the S2 layers of the fibres was detected. Monosaccharides were qualitatively and quantitatively determined by borate complex anion exchange chromatography. Holocellulose content is between 61.5 and 64.7% and Klason lignin content between 29.8 and 31.4%. Subsequent extraction of the soluble compounds was performed with petrolether, acetone/water and methanol/water by accelerated solvent extraction (ASE). Total extractives content in heartwood ranges between 14 to 16% on a dry weight basis. Major compounds in acetone/water extracts were identified as (-)-epicatechin, (+)-catechin and taxifolin, and quantitatively determined by liquid chromatography (RP-HPLC-UV).

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.

Age determination of Acacia erioloba trees in the Kalahari

High quality wood core samples were collected from individual Acacia erioloba trees of unknown age in the Kgalagadi Transfrontier Park. In the majority of samples examined, seasonal changes were reflected in the wood anatomy as bands of marginal parenchyma on the polished surfaces of discs or cores. Estimated radiocarbon age was determined by means of 14C analysis for all samples. There was a strong correlation between the annual growth ring count and estimated radiocarbon age. A correlation was also found between age and stem circumference. Age structure of several A. erioloba populations in the Kgalagadi Transfrontier Park was subsequently determined. It could be demonstrated that the populations growing in the bed of the Nossob River showed poor recruitment; however, no clear relationship was found between flooding and regeneration of A. erioloba in the riverbed. The population growing in the dune field had a healthy age structure.

Anatomia do caule de Serjania corrugata Radlk. (Sapindaceae)

A estrutura anatômica do caule adulto de S. corrugata foi detalhada, com o objetivo de contribuir para a identificação de caules de lianas usadas comercialmente. São destacadas as seguintes características: variação cambial do tipo massa xilemática dividida, dimorfismo vasal, faixas de parênquima não-lignificado no lenho, placas de perfuração simples, séries cristalíferas no xilema e floema secundários, placas crivadas simples, anel de esclerênquima no floema não-condutor e mensurações dos elementos celulares do lenho.

Regular cambial activity and xylem and phloem formation in locally heated and cooled stem portions of Norway spruce

The effect of heating (23–25°C) and cooling (9–11°C) on regular cambial activity and xylem and phloem formation in the stem portion of Norway spruce was investigated. Adult trees were sampled at 21-day intervals during the 2005 vegetation period. Continuously elevated temperatures increased the rate of cell division in the first part of the growing season, but did not significantly prolong cambial activity at the end of the vegetation period in the heated tree. Low-temperature treatments shortened regular cambial activity and slowed down cell production. The xylem growth ring was wider in the heated sample and narrower in the cooled sample compared to the control. The temperature in the cambial region was only negligibly transferred along the stem from the site of its application. In general, the temperature in the cambium was affected by a long-term rise or drop in air temperatures. Both experiments affected the structure and width of phloem growth increments. The tangential band of the axial parenchyma was not continuous in the cooled sample. The number of late phloem cells was reduced in the cool-treated sample and increased in the heat-treated sample. Our experiments confirmed the effect of constantly increased or decreased temperatures on regular cambial activity in Norway spruce.

From Tonic-cups to Bitter-cups: Kwasi bita beker from Suriname : Determination, past and present use of an ancient galenic artefact

In the main markets of Paramaribo (Suriname), many stands offer what is locally called “ Bitter-cups”, or “ Kwasi bita beker”, small footed-cups, roughly carved from a whitish wood. The use of these cups is strictly medicinal and it seems to be restricted to Suriname, as they are not found in neighbouring countries (Guyana, French Guiana). The aim of this study was to identify the botanical origin of Bitter-cups still in use in the Saramaka traditional medicine (as information from field people was controversial), and document the ethnopharmacology of this original galenical artefact. Microscopic and high performance liquid chromatography (HPLC) analyses were carried out on Bitter-cup, and anatomical criteria (marginal parenchyma band, size of intervessel and vessel-ray pits, rays width and rays composition, vessels clustering, frequency and size of parenchyma pits) together with HPLC profiles of the macerates showed that the wood cup was similar to Quassia amara L. (Simaroubaceae) wood. Ethnopharmacological investigation indicates that the use of these cups is simply due to the pharmacological properties attributed to “ bitters”, and is strongly linked to tradition and cultural attitudes. This study also emphasizes the long lasting use of these cups, now restricted to Suriname only, with almost no variation over one century.

Growth rings in cerrado woody species: occurrence and anatomical markers

Growth ring occurrence was investigated in 48 representative species of cerrado in the state of São Paulo, Brazil. We characterized growth ring markers and described the growth layer structure of the basal portion of the most developed stem branches in woody plants. Growth rings were poorly defined in 33%, well defined in 61% and not discernable in 6% of the species studied. Various anatomical features were used as growth markers, such as: thick-walled latewood fibres; radially flattened latewood fibres; fibre zones; distended rays; marginal bands of axial parenchyma; marginal lines of parenchyma; and closeness of the narrow bands of scalariform parenchyma. In a single species, different growth ring markers often occurred together. Within growth layers, variations in the anatomical features were observed. Variations in the axial parenchyma distribution within growth rings in Vochysia cinnamomea, Qualea multiflora, V. rufa and V. tucanorum, wood are here reported for the first time. Variation in the distance of the axial parenchyma in narrow bands along the rays within growth layers in Annona coriacea, A. crassiflora, Diospyrus hispida and Roupala montana wood is also reported. Phenology and habit of the studied species were important aspects related to both growth ring presence and distinctness as well as to the anatomical features' variations within growth layers.

SEASONAL VARIATION IN WOOD FORMATION OF CEDRELA FISSILIS (MELIACEAE)

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.

Laparoscopic left hemicolectomy in a patient with cirrhosis scheduled for liver transplantation

Laparoscopic liver resection has not yet gained wide acceptance among hepatic surgeons, mainly because of the difficulties encountered in dealing with possible intraoperative bleeding. A new technique of laparoscopic liver resection is presented. A 43-year-old man with a large and symptomatic hemangioma underwent a laparoscopic radiofrequency energy-assisted liver resection. After induction of pneumoperitoneum, four trocars were introduced and intraoperative ultrasonography and coagulative desiccation were performed along a plane of tissue 1 cm away from the edge of the lesion using the Cool-Tip radiofrequency probe and a 500-kHz, radiofrequency generator. The necrosed band of parenchyma then was divided and the specimen removed. The operative time was 300 min with a resection time of 240 min. The intraoperative blood loss was 75 ml. The postoperative course was uneventful and the patient was discharged on postoperative day 6. Laparoscopic radiofrequency-assisted liver resection is feasible, and with greater experience may contribute to the wider use of mini-invasive video-assisted liver surgery.

Annual tree rings revealed by radiocarbon dating in seasonally flooded forest of the Mapire River, a tributary of the lower Orinoco River, Venezuela

The occurrence of seasonal growth rings in the wood of Campsiandra laurifolia, Acosmiun nitens, Pouteria orinocoensis and Psidium ovatifolium, common species growing in the flooding forest of the Mapire river, was analyzed using wood anatomy and ring- width analysis. The test of the annual ring formation was performed using radiocarbon analysis based on the nuclear weapon effect. All species showed growth rings visible to the naked eye. The ring boundaries in all cases were marked by bands of marginal parenchyma. The index ring-width curves of the four studied species showed a strong relationship with the fluctuation of the water river level during the non flooded months, suggesting that an increase in the water level during these months positively influenced the growth indicating that the rings were formed on an annual basis. The content of radiocarbon in the wood of anatomically predated rings of Campsiandra laurifolia and Pouteria orinocoensis confirm these results. All studied trees are slow growing with less than 2.5 mm annual increment.

Annual rings in native and introduced forbs of lower Michigan, U.S.A.

Almost nothing is known about the presence of annual growth rings in North American perennial herbs and, correspondingly, the age of forbs is also largely unknown. In this study we sampled established individuals of dicotyledonous perennial herbs (60 species) in different habitats in lower Michigan (U.S.A.) and analyzed the main roots for the presence of growth rings in the secondary xylem. Two thirds of the species showed clearly or relatively clearly demarcated growth rings in the root xylem that are most likely annual rings. The anatomical patterns contributing to the delineation of growth rings in the root xylem differed widely, particularly among plant families. These included variations in vessel diameter and vessel density and differences in the presence and extent of tangential bands of fibres or lignified parenchyma, respectively. Among introduced species and in disturbed habitats (meadows, ruderal sites), clearly demarcated growth rings were found more frequently than among native species and in semi-natural and natural habitats (old fields, prairie remnants, open sandy vegetation). While most of the sampled plants were young (2 to 3 years old), the age distribution in the whole sample was relatively wide (2- to 16-year-old plants). Older individuals ([Formula: see text]6 years old) were mainly found in semi-natural and natural habitats. Results indicate that the analysis of annual rings in the root xylem of perennial herbs (herb-chronology) may be widely used as a reconstructive method in plant ecology over extensive geographic areas with seasonal temperate climate. Research into plant invasions may particularly profit from a high proportion of forb species in disturbed habitats that show clearly demarcated annual rings.Key words: age determination, anatomical patterns, annual rings, perennial herbs, population ecology, secondary root xylem.

The Distance to Which Wound Effects Influence the Structure of Secondary Xylem of Decapitated Pinus pinea.

Decapitation of stems of annuals and trees for the study of vascular and fiber differentiation with or without hormonal application is a common procedure. There is controversy about whether wound effects play a role in such experiments, and to what distance from the point of decapitation. To examine this question, the distance from the point of decapitation at which apparent wound effects are obvious developmentally, was studied in decapitated 4-year-old Pinus pinea plants. The wound effects just below the cut included differentiation of many traumatic resin ducts, a parenchyma band instead of tracheids, more tracheid files, and a higher proportion of late wood. The increase in the number of resin ducts was still considerable and statistically significant 10 cm below the point of decapitation compared with the nondecapitated control. These results indicate that in pines, wound effects in the first 5 cm below the decapitation point (a common point for tissue examination) cannot be ignored in experiments on the regulation of vascular differentiation.

FORMATION OF INCREMENT ZONES AND INTRAANNUAL GROWTH DYNAMICS IN THE XYLEM OF SWIETENIA MACROPHYLLA, CARAPA GUIANENSIS, AND CEDRELA ODORATA (MELIACEAE)

The pattern of growth increment zones, the cambial growth dynamics and the structural variation in wood formation of Swietenia macrophylla King, Carapa guianensis Aubl., and Cedrela odorata L. (Meliaceae) were investigated in order to understand the relationship of site conditions and sustainable growth in Central Amazonian plantations. Trees were available from 8-, 17-, 23-, and 57-year-old plantations, and from primary forests in Manaus (Amazônia), Santarem (Pará), and Aripuanã (Mato Grosso). The wood anatomical structure and the annual increments of 61 Swietenia, 94 Carapa, and 89 Cedrela trees were studied for different tree heights. The curves of annual increments were cross-dated and tested for synchronisation. The cambial growth dynamics of up to 52 trees per species were dated by means of dendrometer measurements, monthly labelling by pinmarkers, and extracted cambium samples investigated using a microscope. The intraannual course of the growth and structural variation was compared with the water supply of the soil and insect attacks (Hypsipyla grandella (Zeller) Lep.). In Swietenia and Carapa parenchyma and vessel bands as well as bands of resin canals were observed. Within the xylem of Cedrela, alternating bands of fibres and vessels surrounded by paratracheal parenchyma were found; bands of resin canals were only occasional. In the juvenile wood of Swietenia and Carapa no synchronization of the increment curves was possible, whereas the increment curves obtained in the juvenile wood of Cedrela showed parallel run in growth. The increment curves obtained in adult wood of Swietenia and Cedrela indicate an annual formation of increment zones, whereas the number of increment zones in the xylem of Carapa was approximately 50% higher than the tree age (years) indicating that the growth increments of Carapa also were not annual during the adult phase of growth. The study of the intraannual growth dynamics of the trees showed that the formation of parenchyma bands in Swietenia is induced by dry periods before a cambial dormancy. The formation of parenchyma bands of Carapa was induced by extremely dry and extremely wet periods before a cambial dormancy, whereas fibre bands in Cedrela were induced by dry periods before a cambial dormancy and the formation of vessel bands embedded in paratracheal parenchyma was induced by wet periods after a cambial dormancy. In addition, insect attack (Hypsipyla grandella) induced locally restricted formation of parenchyma bands and bands of resin canals in Swietenia, Carapa and Cedrela.

WOOD ANATOMY OF THE BRAZILIAN SPECIES OF SWARTZIA AND CONSIDERATIONS WITHIN THE TRIBE SWARTZIEAE

Fifty-one Brazilian species and varieties of Swartzia Schreber and eight other genera from the tribe Swartzieae were examined. Features with the greatest diagnostic value for the tribe are intervascular pit size, ray width and frequency, storied structure, axial parenchyma strand length, parenchyma band width, and vessel diameter. We analyzed the wood anatomical data using average linkage cluster analysis and canonical discriminant analysis. With weighted features, cluster analysis grouped the species and varieties of Swartzia into four distinct groups and tribe Swartzieae into seven groups. With unweighted features for both Swartzia and Swartzieae, the canonical discriminant analysis showed that linear combinations of the variables storied structure, number of tiers per millimetre, axial parenchyma strand length, ray height, intervascular pit size, and exclusively uniseriate rays were good discriminators among the groups. We discuss the grouping of the species of Swartzia and compare other genera within the tribe Swartzieae to the four groups of Swartzia.

Anatomia comparada do lenho de Copaifera langsdorffii Desf. (Leguminosae-Caesalpinoideae) de floresta e cerradão

The present study compares qualitative and quantitative characters of the wood of a tree species (Copaifera langsdorffii Desf.-Leguminosae-Caesalpinoideae) from semideciduous mesophytic forest and cerradao. Analysis revealed vessels with significantly larger diameter in trees from cerradao and intervascular pits being significantly larger in trees from forest. In contrast to the trees from the forest, gelatinous fibers, which have a special layer innermost of the wall, were found in great quantity in trees from cerradao. Furthermore, the presence of subdivided marginal parenchyma and the absence of axial canals in some of the parenchyma bands are for the first time mentioned for this species.