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Anatomically in cross section, the palm stem has two distinct regions, the cortex and central cylinder, although there is no clearly identifiable layer between them. The vascular bundles (VBs) appear as dark dots in the central cylinder (mexican fan palm).
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Comprising a natural and distinctive group, palms (Arecaceae) differ from other woody plants in their structure and growth features that require or offer unique and sometimes advantageous landscape management opportunities. Although palms are a mostly tropical group that lacks dormancy and cold tolerance, there are numerous species possessing suffi...
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Context 1
... cross section, the palm stem has two distinct regions, the cortex and central cylinder (Fig. 3) (Tomlinson, 1990). The cortex, a very narrow band on the outside of the stem, has a thin outer covering or skin composed primarily of thick-walled, sclerified (hardened) cells, which is sometimes referred to as pseudobark, although it has no relation to bark of dicotyledo- nous and coniferous trees. Relatively unspecialized parenchyma ...
Context 2
... cross section, the palm stem has two distinct regions, the cortex and central cylinder (Fig. 3) (Tomlinson, 1990). The cortex, a very narrow band on the outside of the stem, has a thin outer covering or skin composed primarily of thick-walled, sclerified (hardened) cells, which is sometimes referred to as pseudobark, although it has no relation to bark of dicotyledonous and coniferous trees. Relatively unspecialized parenchyma ...
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Citations
... Generally, Hyphaene species have dichotomising trunks whose growth is coupled with developing an independent, adventitious root system (Tomlinson & Huggett, 2012). Therefore, the trunks are characterised by high water and carbohydrate storage for plant use during the drought (Francisco-Ortega & Zona, 2013;Hodel, 2009). This stored water is a valuable resource for humans and wildlife in arid regions and other areas, especially during dry periods when other water sources are scarce. ...
Hyphaene, commonly referred to as mkoche(Plural Mikoche) and in Swahili, is a species belonging to the Palmae (Arecaceae) family and is found in various parts of Africa, including Maputaland coastal plains in southern Mozambique, Turkana, Samburu, and Marsabitin Kenya, and the coastal regions of Tanzania and Kenya. Despite its widespread presence and resistance to climate change, the economic potential of mikochein Tanzania has yet to be fully unlocked. Therefore, a comprehensive literature review was conducted to identify the various uses of the Hyphaenetree globally, which could further be fully exploited within Tanzania. The findings revealed that the fruit of the Hyphaenetree is a good source of fibre, antioxidants, B-complex vitamins, essential minerals, monosaccharides, essential oil, and flavonoids, which are important compounds for human nutrition and health. In addition, H. coriaceaproduces edible nuts and palm wine in Maputaland coastal plains in KwaZulu-Natal, South Africa, and H. coriaceais known to produce edible oil from its nuts. Furthermore, the tree is used as a construction material for shelter, and its leaves are used to make woven products such as baskets, mats, and hats due to their strength and fibre length. Therefore, with favourable conditions for mikoche growth in Tanzania, particularly in the coastal regions, mikochecan contribute to the economy by using its various parts to produce food and non-food products. However, further research is required to understand the diversity of uses, consumption constraints, and opportunities for mikocheasa natural resource in Tanzania.
... Terminal flowering of the main axis leads to the death of the whole plant (7-8); (C) C. obtusifolia trajectory: the architectural unit based on three axis categories (C1, C2, C3) is progressively established and completed with the expression of flowering (1-2). Branchesand their twigs flower terminally following an acropetal gradient along the main axis(3)(4)(5). The branch's vegetative growth continues through sympodial construction(5)(6)(7). ...
Semelparity is the ability of an organism to reproduce once and then die. In plants, this life history strategy is also named monocarpy. After a unique flowering event, the whole plant dies. This strategy inherently characterizes annual and biennial herbaceous, and frequently occurs in bamboo and palms, but remains extremely rare in woody branched plants such as shrubs and trees. Branched plants are long-lived organisms and present multiple meristems (growing points) that are as many opportunities to flower at different times. Therefore, the persistence of the monocarpic strategy in such plants is questionable since a premature death of the individual in the decades before the flowering will prevent any descendants. About twenty-nine monocarpic canopy tree species are recorded worldwide all included in two tropical and subtropical genera: Tachigali (Fabaceae) and Cerberiopsis (Apocynaceae). This latter is endemic to New Caledonia and consists of three species with different habits. While C. neriifolia and C. obtusifolia are respectively a polycarpic (multi-flowering) treelet and shrub, C. candelabra is a large monocarpic rainforest tree. In this thesis, we investigate the morpho-anatomical bases of monocarpy, its underlying ecological implications, and functional adaptations. (1) Through a comparative analysis, we highlight that the variation of only a few architectural traits has led to the emergence of this strategy within the genus Cerberiopsis, and flowering in C. candelabra is independent of tree age, size, or senescence. (2) Based on growth monitoring, we show that C. candelabra exhibits high survival and growth rates at the juvenile stage, and forms monodominant regenerations. These two studies pave the way to (3) an integrative retrospective analysis: we reconstruct the developmental trajectories of the Cerberiopsis species and demonstrate that their growth phenology is sensitive to climate seasonality. C. candelabra exhibits strong structural and temporal regularities, as well as a high degree of synchronization between all developmental processes. These particularities might have been preconditions for the evolution of its monocarpic strategy. Finally, my work introduces (4) a new type of annual growth ring that results from the production of circular tension wood, a potential adaptive feature related to the cyclonic season of New Caledonia. The processes underlying monocarpic flowering and its triggers are discussed throughout the different chapters of this thesis. We suggest that flowering depends on endogenous preconditions and is triggered in C. candelabra by large-scale disturbances such as fires and tropical cyclones.
... Trees belonging to native species were also selected to investigate their characteristics compared to exotic trees. In addition, palm species were chosen due to their abundance in the dataset, as well as their distinctive structures and growth features compared to other woody plants (Hodel, 2009). These species types were coded as different binary variables with "true" values indicating the presence of the species. ...
Trees in the urban environment are affected by a range of place-specific environmental and cultural factors. Nevertheless, many factors interact with each other and produce high variabilities in urban forest structures, spatial configurations, and growing conditions within the urban fabric. The variabilities and relationships among these factors require a modelling framework that incorporates variables related to the spatio-temporal information of individual trees and site characteristics. Using roadside trees in a residential district in Hong Kong, this study examined their species compositions and spatial distributions among zones with various development histories. Structural equation modelling was applied to investigate the interactions among variables concerning the physical environment, temporal changes, species selection, spatial patterns, and tree sizes. A few abundant species dominated the urban forest, with uneven distributions of roadside tree densities and species-specific clusters found within the study area. The empirical results showed (i) the physical environment influenced the existence of roadside trees, the occurrence of specific species and tree growth; (ii) species selection mediated the influences of the physical environment on tree sizes and spatial patterns; (iii) despite the linkage between existing tree patterns and development histories, replacement plantings further modified the compositions and reflected a shift in preferences; (iv) the proximity to nearby urban structures and the spatial properties among planting locations were important factors in spatial planning. Hence, urban forest managers play a crucial role in mediating the interactions among physical drivers, planting histories, and tree performances. It is recommended that species diversity, especially native trees, should be promoted within the study area, while planting strategies matching site dimensions, species and attainable sizes should also be prioritised. By generalising the relative effects that determined the existing patterns of urban forests, the modelling framework can provide a strategic reference for target-oriented tree management in Hong Kong and other cities.
... The Pinanga genus contains both endangered and invasive species; thus, assumptions about population dynamics are likely to vary considerably (Shapcott 1999;Singh et al. 2014;Dyer et al. 2018;Zulkarnaen et al. 2019). Many Pinanga, while single stemmed, basally resprout and can form multi-stemmed clumps which may also enhance individual persistence (Shapcott 1999;Dransfield et al. 2008;Hodel 2009). ...
Borneo is the centre of diversity of the palm genus Pinanga . At least 13 understory species have been recorded in the Ulu Temburong National Park in Brunei, but little is known of their persistence. Changes in populations of Pinanga understory palms may be indicative of more widespread changes due to climate change, such as changes in rainfall, which may be important for the palm diversity in the protected area. However, we know little about the population dynamics of these palms, how persistent their populations are or if they behave similarly over long time frames. In 1998, populations of five co-occurring species of Pinanga at several locations in the Ulu Temburong National Park were documented. This project aimed to undertake a comprehensive resurvey of the original five Pinanga palm species populations in order to assess if they showed similar population changes across sites and species after two decades. Overall, most species maintained their population size in the surveyed region but not consistently among sites, and one species significantly declined in abundance. There was considerable variation in population growth rate (R) within and among species and sites that was significantly correlated with density and the percentage of multi-stemmed plants. There was evidence of pulsed recruitment in some species and or sites rather than steady or exponential patterns of population growth.
... In this regard, the palm stem is structurally similar to a steel-reinforced concrete pillar: vertical vascular bundles are the steel rods and the parenchyma cells are the concrete (Tomlinson et al. 2011). The result is an extraordinary tough and flexible stem that rarely breaks (Hodel 2009;Wegst 2011). In contrast to previous ideas, other authors indicate that it is necessary to carry out palm risk assessments because, indeed, palm trees do uproot and break (Sterken 2021a(Sterken , 2021b. ...
... To the periphery of the stem there is a region of sclerified tissue (i.e. the cortex), and a very thin epidermis, sometimes collectively known as the "pseudobark" (Broschat 2016). Besides, palm stems lack a peripheral vascular cambium because they do not have secondary growth; thus, palms do not thicken much once vertical elongation occurs, and do not have capability to repair damaged tissue (Hodel 2009). An anatomical feature of palm stems is that the material dry density increases towards the stem periphery (cortex) and base. ...
Biological materials (orthotropic materials), like wood, can offer good mechanical properties with a minimum amount of material, making their internal structure the suitable one to be applied on bio-inspired structures. The knowledge of the exceptional structural performance of palm trees, and specially its response to different loading conditions, provides useful information when lightweight structures with high slenderness ratio are desired. Recent researches focused on the analysis of palm trees subject to static loading conditions, ignoring the fluctuating nature of the wind speed. The purpose of this study is to simulate in a computational efficient way the effect of dynamic loading conditions applied on palm trees. Using the mode displacement method, the number of degrees of freedom of a dynamic finite element analysis can be drastically reduced with a minimal loss of accuracy. It was applied to simulate the behavior of structures comprised of an orthotropic material subject to a stochastic dynamic load. The influence of the number of selected degrees of freedom has also been studied. In addition, an exponential integration method is proposed to perform the time integration procedure. The results obtained show that a properly reduced model suitably represents the full finite element model without any appreciable loss of accuracy; it is also shown that computational cost can be drastically reduced. This method could give an appropriate computational representation of the behavior of orthotropic structures, and it could be used for studying more complex bio-inspired structures.
... In the past, motivations to plant palms over other species included the desire to invoke the sense of the exotic [25][26][27] and, on a public level, to demonstrate colonial connections and aspirations [28,29]. Today, many of these early plantings form an integral part of several communities' heritages [30][31][32]. ...
Canary Island date palms (Phoenix canariensis) have been planted as a landscaping feature
plant throughout warm, temperate, and subtropical climates. The physical amenity provisioning of this species (shade effects, microclimate amelioration, water usage, etc.) has so far not been systematically assessed. This paper reports on temperature and humidity measurements in both a suburban and a rural location in SE Australia. The study demonstrates the effects of the palm canopy as regulator of humidity and provider of shade and, thus, amenity values in urban landscape settings. Drawing on published energy savings and growth requirements of the plant, the paper argues that Canary Island date palms are landscaping plants suitable to ameliorate the microclimate in urban neighborhoods with varied socio-economic conditions.
... Wildfires can kill palm seedlings, however, adult M. flexuosa are considered to be fire-tolerant [5] because they are protected by a rhytidome (dead outer hard bark [22]) and have monocotyledonous vascular bundles with numerous water channels scattered throughout the stem [23]. These anatomical structures (i.e. the rhytidome and scattered vascular bundles) make palms less vulner-able to surface damage [22][23][24]. Additionally, the outer portion of the bark produces suberin (a complex polyester biopolymer) that prevents water loss [25]. ...
Moriche palm (Mauritia flexuosa Linn f. [Arecaceae]) is a dominant species in the savanna
margins of the Caribbean island of Trinidad. The savanna margins are frequently subjected to
fires and the moriche palm, like many palm species, is adapted to cope with a degree of fire
damage. These palms also frequently host large termite nests that tend to burn during fires,
which causes further damage to the palm stems. This paper explores the possibility that the
combination of termite nests and frequent fires can increase tree mortality. Two post-fire
surveys were conducted to record, evidence of fire exposure, fire damage to termite nests
and fire damage to palm stems. In both surveys, the majority of palms with termite nests
suffered fire damage to their stems, while none of the termite-free palms showed damage.
Furthermore, a comparison of nest size and damage to the bark showed stems with larger nests
had significantly more damage than those with smaller or no nests. The results suggest that the
presence of termite nests increases the extent of fire damage to palm trunks by providing
a point of combustion that focuses flames on the already compromised stem tissue. Long-term
studies are warranted to investigate the impact of repeated fires on wild arborescent palm
populations.
... Palms are ubiquitous ornamental plants in many urban and sub-urban landscapes in warm temperate to tropical climates. Often planted during the palm craze of the late nineteenth and early twentieth century, the palms evoked a sense of the exotic (Watts, 2000;Hodel, 2009;Piana et al., 2019) and, on a public level, also to demonstrate colonial connections and aspirations (Casid, 2015;Griggs, 2015). They also conjured up a sense of status reflective of a life of leisure and luxury along the French and Italian Riviera (Campodonico et al., 2015;Spennemann, 2018a). ...
With the increasing expansion in urban areas, many species have adapted to utilising horticulturally used plants as alternate or augmentary food sources, in particular, during winter – when native foods are largely absent. Ornamental palms, particularly Canary Island Date Palms, fruit continuously during most of the year and thus provide a stable food supply. Based on observational, metric and bio-chemical data, this paper examines the role Canary Island Date Palms can and do play in the nutrition of frugivorous animals, in particular, for birds. It demonstrates that with its nearly year-round provisioning of drupes, the palm plays a major role as a ‘staple’ and backup food source for several species.
... This technique leads to the creation of wounds. Palms are perfectly capable to "heal" (to compartmentalize) wounds, although the myth (Shigo, 1993) or false idea that they don't have this capacity is largely widespread (Howard et al., 2001;Moya et al., 2005;Hodel 2009;Dembilio et al., 2015). Because of the palms capacity to heal, Tomlinson himself in his famous book on "The structural biology of palms" defended the interest of injection (Tomlinson, 1990). ...
In the framework of the fight against a quarantine pest like the red palm weevil (RPW), the interest of insecticide treatments goes far beyond protecting or curing the palms in the infested zones. In the case of treatments by injection, these treatments do not kill the adults but prevent RPW reproduction and multiplication. Regarding the curative treatments, we must speak of sanitation treatments as the main objective of these treatments is not to save the infested palms but to eradicate the weevils that they contain.The main problem regarding the treatments against the RPW is not really the type of insecticides or of biological agents applied but the way to reach the pest and to increase their persistency. Regarding preventive treatments, the recent rectification of false ideas on RPW oviposition and the difference that has been established between palms (species and morphology) have led to recommend soaking treatments precisely targeted and differentiated according to the palms. No significant advance regarding the type of insecticide (synthetic or natural) to be used can be noticed. Many insecticides are efficient against the RPW but treatments must be repeated very frequently to be efficient. Research to increase their persistency has been initiated.Injection technique for preventive or sanitation treatments can be useful in precise circumstances. The limitation factor is that these treatments cannot be repeated too often as they create a wound that can compartmentalize but will never be covered by new tissues, at the difference of what occurs with trees. For ornamental palms, including ornamental date palms, new injection technique based on micro-infusion of an avermectin insecticide allows to protect the palms very easily and at very low cost over a period of one year.
... 2016 de las condiciones de crecimiento. La generación de raíces de crecimiento limitado por encima de la base del tallo de algunas palmas, la zona de proliferación de las mismas y su patrón de regeneración, son aspectos de vital importancia para el establecimiento exitoso luego del transplante de palmas ornamentales, debido a las raíces laterales que se desarrollan de las primarias que han sido cortadas Pittenger et al. 2005;Hodel 2009;Tomlinson et al. 2011). ...
The anatomy of aerial short roots of Oenocarpus bataua that arise from the stem base up to approximately 80 cm from above ground level is described, comparing this structure between individuals at different distances from the apex and between primary and secondary roots. Samples were collected in Zamora Chinchipe (Ecuador). Transverse, longitudinal sections and macerates were made using classic techniques. The studied roots lacked apical meristematic tissue. Principal variations between individuals are the presence of medullar isolated tracheary elements and deep lobulated endodermis in thicker primary roots. Another differences between individuals are found in the exodermis and outer cortex in terms of absence, presence or variation on the number of cell layers and wall thickening, while the structure of the inner cortex showed more constancy. At different levels from the apex, primary roots show centrifugal sclerification of the fundamental tissue bordering the vascular tissue. Secondary roots have a simpler and less variable anatomy.
