Rays hamper intrusive growth of vessel elements

Key message In some circumstances vessel elements, both broad and narrow, enlarge only symplastically in tangential direction. Rays play a special role in regulating intrusive enlargement of vessel elements. Abstract The aim of this study was to analyse relations occurring between vessel elements and surrounding cells, i.e. susceptibility to separation of walls of cells occurring in the vicinity of vessel elements, with regard to their type—cells of the axial/radial system. On the basis of separation/lack of separation of cell walls, and thus change in cell contacts/lack of change in cell contacts, we have estimated the contribution of particular types of growth—intrusive and symplastic—in …

Rapid change in forms of inorganic nitrogen in soil and moderate weed invasion following translocation of wet meadows to reclaimed post‐industrial land

Anthropogenic expansion and loss of natural environments calls for the more sustainable use of resources, including land. To combine the conservation of highly valuable meadow habitat with reclamation of post‐industrial land, 1.3 ha of turf were translocated from an urban area to basins constructed near an abandoned quarry. In contrast to the usual method of choosing similar habitats as salvage sites, the selected quarry possessed different environmental properties to the meadows, challenging their acclimatisation. To evaluate the project, we monitored three meadows (Molinion caeruleae alliance) for three seasons: immediately before the transfer and for 2 years afterwards. We recorded veget…

Translocation of meadow, heath and fen to the habitat garden : the first insights after 4 years of the experiment

Controversy over the Mode of Growth of Cambial Cylinder

Based on mathematical modelling, this review article describes the mechanism of expansion in the circumference of vascular cambium due to radial growth leading to increase in the tree-trunk diameter, and emphasizes upon the huge difference in the rate of symplastic growth of cambial initials in two different directions, viz. radial and circumferential. On the basis of anatomical evidence regarding the role of symplastic and intrusive growths, the long-standing hypothesis that the intrusive growth contributes to the increase of cambium circumference has been falsified. It has been shown with the help of mathematical calculations as well as anatomical observations that only symplastic growth …

Modelling for rearrangement of fusiform initials during radial growth of the vascular cambium in Pinus sylvestris L.

In contrast to common belief, recent studies have confirmed that intrusive growth of fusiform cambial initials has a significant role in the rearrangement of the initials, but does not contribute to the cambial circumference increment. We observed a rapid rearrangement of cambial initials on a long series of transverse sections of the vascular cambium and the wood of a 50-year-old pine (Pinus sylvestris L.) tree. A comparison of cell arrangement in consecutive sections, as well as a critical analysis of tangential reconstructions, has confirmed that changes in cell locations in a group of cells on the tangential surface caused no change in the total tangential width of the whole group. Mode…

Long slide holders for microscope stages

ABSTRACT The use of automated techniques for image analysis of microscopic wood specimens together with new procedures for the preparation of stained xylem tissue support the use of quantitative wood anatomy. These techniques and procedures are especially useful in the studies of retrospective analysis of xylem phenology, reaction(s) of trees to stressful conditions of growth, or reconstruction of long-term growth trends. The unresolved technical problems during the digitalization of cross sections from entire increment cores were stabilization and precise shifting of long microscopic specimens onto the optical microscope stage. For this reason, we have developed a long slide holder for mic…

Intrusive growth of initials does not affect cambial circumference in Robinia pseudoacacia

AbstractThis study aimed to test the hypothesis whether intrusive growth of initial cells is related to the increase in circumference of Robinia pseudoacacia vascular cambium—both qualitatively and quantitatively. The mode of intrusive growth of cambial initial cells was also studied. Samples collected from tree trunks were examined using series of semi-thin transverse sections. Anatomical reconstructions of radial and tangential planes of analysed fragments of cambial tissue were made. Observations and measurements have shown that the intrusive growth of R. pseudoacacia initial cells does not contribute to an increase in tangential dimension of observed tissue fragments where cell rearrang…

Is the riparian habitat creation an effective measure of plant conservation within the urbanized area?

The study presents results of habitat creation and riparian vegetation recovery in artificial oxbow lakes in urbanized area within the large river valley. The investigation of open water, rush and wet meadows flora and vegetation in three ponds located in the city centre of Opole was conducted in years 2001–2013. Oxbow lakes were constructed as a compensation measure and no vegetation was transplanted into the ponds on purpose. 13-years observation showed that (1) the red-listed species are able to spontaneous reoccurrence after habitat restoration, but they can thrive only in first years of oxbow lakes recolonisation process, (2) there are some restoration constraints, especially in relati…

Direct exposure to solar radiation causes radial growth eccentricity at the beginning of the growing season in Robinia pseudoacacia

Abstract Our study investigated the effect of stem temperature increase on xylem formation in Robinia pseudoacacia tree-trunks, caused by direct exposure to solar radiation. It is important to determine factors which may improve the concentricity of deposited wood tissue and intensify xylogenesis because a strong irregularity of wood tissue deposited in the radial direction in mature trees of R. pseudoacacia reduces the commercial value of the wood. Samples of vascular cambium along with adjacent tissues were collected from the southern (illuminated) and northern (shaded) side of tree-trunks growing in the inner and peripheral (thus exposed to direct sunlight) zones of the research plot. Sa…

Varied response of underground and aboveground plant matter: functional diversity of three different vegetational types after translocation to reclaimed postindustrial land

The indicators of functional diversity are increasingly used to assess the conservation effectiveness of the most valuable habitats. However, little is known about the response of functional traits, their diversity, and divergence in plant communities after translocation. To assess how functional diversity changes on dry heath, meadow, and fen after translocation of entire turfs of vegetation from an airport area to the Botanical Garden in Radzionkow, we used leaf–height–seed (LHS) traits (specific leaf area, height, and seed mass) and vegetative traits (bud bank size, bud bank depth, and lateral spread). We also measured community weighted means and multifunctional diversity metrics (funct…

Functional diversity of different vegetation types does not respond homogeneously to change over time after conservation translocation from a rural landscape to an urbanized one

Abstract The anthropogenic impact on natural environments and the loss of species diversity along with changes in functional diversity call for effective steps to ensure habitat conservation. The functional diversity in particular has suffered in recent decades due to investment and land use changes. The translocation of whole turfs of certain vegetation plots prior to being destroyed is one possible solution for maintaining habitat functional diversity. In the presented paper, we analyse the functional changes in adaptive, regeneration and urbanity plant traits for meadow, heath and fen that were translocated from a rural site to a post-industrial site in a city. After five years of monito…

Apical intrusive growth of cambial fusiform initials along the tangential walls of adjacent fusiform initials: evidence for a new concept

A new study of cambium of Pinus sylvestris L., Tilia cordata Mill. and Wisteria floribunda (Willd.) DC provides fresh clues on the cambial dynamics, rejecting the hitherto held concept that intrusive growth of the fusiform initial occurs between the radial walls of adjacent initials. It demonstrates that intrusion of the elongating initial in fact takes place along tangential walls of adjacent fusiform initials and their immediate derivatives. It also suggests a new mechanism for ‘elimination of initials’. Intrusive growth of the fusiform initial was found to begin with development of characteristic slants, representing a transitional stage of the process of transformation of periclinal wa…

What do we know about growth of vessel elements of secondary xylem in woody plants?

Despite extensive knowledge about vessel element growth and the determination of the axial course of vessels, these processes are still not fully understood. They are usually explained as resulting primarily from hormonal regulation in stems. This review focuses on an increasingly discussed aspect - mechanical conditions in the vascular cambium. Mechanical conditions in cambial tissue are important for the growth of vessel elements, as well as other cambial derivatives. In relation to the type of stress acting on cambial cells (compressive versus tensile stress) we: (i) discuss the shape of the enlarging vessel elements observed in anatomical sections; (ii) present hypotheses regarding the …