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1.
Michela Nocetti Michele Brunetti Fulvio Ducci Manuela Romagnoli Frédérique Santi 《Wood Science and Technology》2010,44(4):621-637
There has been an increase in wild cherry cultivation over recent decades, revealing a need for improvements in planting material
to be used for the production of high quality timber. To date, trial tests have been carried out mainly on growth and tree
architectural traits, while no investigations have focused on wood properties. The present study investigated the variability
of the growth traits and the physical and mechanical properties of wild cherry wood, both within the tree, within and among
clones and between sites. The aims of the study are to provide useful information on the genetics of wood traits in valuable
hardwoods and to discuss how within-tree variation can affect early selection of genotypes. The results suggest that site
was the most important source of variation in growth traits and in the proportion of heartwood, although differences among
clones were highly significant. The number of sapwood rings was very homogeneous both between sites and among clones. Concerning
the wood traits, most variation was detected within the tree, rather than within or among clones or between sites. Within
tree variability seems to be mainly due to heartwood/sapwood presence. However, since there is a high correlation between
heartwood and sapwood properties, a quite efficient selection made on the basis of sapwood should provide an efficient means
of selecting heartwood traits. 相似文献
2.
Massive environmental changes have occurred since European settlement of Australia more than 200 years ago. We examined the demographics of Callitris columellaris F. Muell. (Cupressaceae) across Australia as a potential bio-indicator of environmental change. This species is a widespread obligate seeder with large reproductive potential but is sensitive to fire and herbivory. We measured variation in tree size, stem density, basal area, and seedling recruitment among 90 sites that encompassed a wide range of climates and landscape settings across Australia. Soils from each site were analysed for pH, %C, % N and %P. We also noted evidence of fire and herbivory. Climate at each site was classified as tropical, temperate or arid. Case studies and published literature are used to illustrate the contrasting effects of disturbance in the three climate zones. Climate had a strong influence on stand basal area, density of juveniles and proportions of seedlings and saplings in a population, as well as on prevailing disturbance regimes. Structure of Callitris populations was not strongly associated with soil fertility. In the arid zone overall, and in many individual populations, there were relatively few juveniles and evidence of a chronic recruitment deficit during the last 100-200 years, consistent with reported adverse effects of introduced herbivores on Callitris regeneration. By contrast, most tropical and temperate populations conformed to a negative exponential distribution, consistent with frequent regeneration. Many temperate sites showed extremely dense juvenile populations. In the tropics, juvenile density is lower, probably because of frequent, relatively mild fires that kill many juveniles but few adult trees. We conclude that C. columellaris is a sensitive bio-indicator, and is in decline across much of arid Australia, reflecting the inherent vulnerability of ecosystems in regions with low productivity. 相似文献
3.
Assessment of genetic variation within and among populations is an essential parameter for the effective conservation of forest genetic resources. In this work, the genetic diversity within and among natural populations of the forest tree species Fraxinus angustifolia Vahl in Greece was studied using selected nuclear and chloroplast microsatellite DNA loci. Eight natural populations of F. angustifolia were identified in different locations of the mainland of Greece, and a total of 230 individuals were studied. High polymorphism was observed within populations, while the genetic differentiation among populations was moderate. Intra-population diversity was correlated with geographical coordinates, but no isolation by distance was observed. Of the three haplotypes identified, only one was dominant. Putative ancestral haplotypes were found at small spatial scales suggesting that population expansions could have originated in the region. This study located in sympatry haplotypes that in other parts of Europe are in allopatry, reinforcing the notion of population expansions from the south of Balkans including Greece. Suggestions for conservation and management of F. angustifolia are also reported. 相似文献
4.
Cherry leaf spot (Blumeriella jaapii (Rehm) Arx.) is a very serious disease of wild cherry (Prunus avium L.), which produces premature leaf defoliation and vigor decrease. In two clonal seed orchards of P. avium naturally infected by B. jaapii, spatial heterogeneity and autocorrelation of neighbor damage caused by cherry leaf spot impeded proper analysis of the fungus incidence. The iterative spatial analysis (ISA), based on variography and kriging, was successfully used to eliminate the effect of this spatial heterogeneity in analysis of genetic variation in susceptibility to B. jaapii. Significant differences among P. avium clones were found, with moderate to high broad-sense heritability estimates. Genetic by environment interactions, although significant, were not quantitatively important. A strong relationship between leaf spot susceptibility and bud burst was found. However, other factors must be affecting the genetic variation in leaf spot susceptibility, as differences among clones remained highly significant when considering the bud burst as a covariate in the genetic model. 相似文献
5.
Effective management of forest wildlife requires information about habitat features that can be altered by operations, if those habitat features promote reproductive success and survival, and if changes in organism density influence reproductive success and survival. Habitat selection studies often provide the first type of information, although relatively few studies examine how different selection decisions or densities of organisms influence fitness measures or measure habitat features at relevant operational scales. We examined patterns of habitat selection and estimated how habitat use, territory size, and conspecific density were associated with territory success (probability of a territory producing one or more fledglings) for the dusky flycatcher in 2002–2003 on eight study plots in managed grand fir (Abies concolor) forests in Idaho, USA. Flycatchers selected territories with greater cover of deciduous vegetation in two different height strata (1–2 and 3–4 m) and reduced cover of conifers less than 4 cm dbh compared to what was available. While flycatchers selected habitat characteristics at the territory scale, model selection results did not support any associations between vegetation features and territory success. Territory success had weak positive associations, for a given territory size, with conspecific density, although the relationship was highly variable. An interaction between territory size and density was not supported. These results are consistent with the view that avian breeding habitat selection occurs at multiple scales, and that the nest site scale may explain more of the variance in reproductive success than larger scales. Our results suggest that operational management of vegetation features, which often occurs at the stand scale, may not influence variation in critical demographic metrics. Increasing total shrub cover of commonly used plant species should benefit the dusky flycatcher, as well as other shrub-nesting forest birds, but stand-level habitat alterations alone cannot be relied upon to increase reproductive success, an important component of population change. 相似文献
6.
Early on, researchers of evolutionary biology recognised that heterogeneity in the mating environment is an important source of variation in mating patterns. Focusing on the mating environment, we assessed the effect of conspecific tree density on mating patterns in the naturally scattered forest tree Sorbus domestica L. In an area of more than 100 km2, we mapped and genotyped all 189 adult trees and performed a paternity analysis on seeds produced by single mothers. Despite a self-incompatibility system, average selfing rate was 31.9%, but with high variation among mother trees. Over 70% of this variation was explained by local density of conspecifics (i.e. within a radius of 300 m), with isolated trees being more prone to selfing. While we detected high selfing rates in progeny, adult trees showed no signs of inbreeding. As almost all inbreeding in the offspring could be attributed to self-fertilisation, we hypothesise that there is strong selection against selfed individuals. The effective reproductive output of isolated trees, which mainly self, is therefore greatly reduced. These findings have important consequences for the management of naturally scattered, insect-pollinated temperate tree species, often belonging to the family of Rosaceae. For these species, local density of conspecifics should be maintained above a certain threshold (i.e. 0.05 trees/ha in S. domestica), to avoid negative fitness consequences from selfing. 相似文献
7.
《Forest Ecology and Management》1999,121(3):239-250
Nothofagus nervosa (=N. alpina) is one of the most important native forest tree species of Argentina, with a very small natural distribution area, fast growth and a high wood quality. Its overexploitation in the past seriously affected some populations and made others disappear, making it necessary to implement conservation policies and breeding programs.In order to study the genetic and geographic variation of the species, seeds from a total of 29 populations from the entire natural distribution area in Argentina were harvested, 11 of them during four consecutive years. Annual and geographic covariation of seed production, seed weight and proportion of seeds damaged by insects were analyzed.Significant differences among populations and among years for all studied traits were found. Seed production was highly variable, both among populations and among years. `Partial mast years' seem to occur every two years, whereas the occurrence of `full mast years' has a lower frequency. A significant population × year interaction was found both for the proportion of damaged seeds and for the seed weight. The proportion of seeds damaged by insects was very important, reaching >80% of the total seed produced in some populations. The differences in the quantity of attacked seeds among years are discussed in relation to seed production, insect's life cycle and climatic factors. Seed weight was also variable among populations and years, despite the small natural distribution area of the species in Argentina. Best seed quality, according to lower proportion of damaged seeds and higher seed weight, was observed in the analyzed `full mast year'. This would also imply a better genetic representation of populations with seed samples harvested during these years. A lower proportion of damaged seeds as well as the heaviest seeds were also found among those seeds fallen during the first part of the seed-fall period.The found covariation is discussed in relation to patterns of genetic variation previously found in this species and to the implementation of genetic studies and conservation and breeding programs. 相似文献
8.
Yellowwood (Cladrastis kentukea) grows in small, widely scattered populations in the wild, but is also a popular ornamental tree that thrives when planted in urban areas outside its natural range. Since the small native populations of yellowwood in several states are considered at risk of extirpation, the cultivated population could serve as an ex situ repository of yellowwood genetic diversity that could be used to restore lost local populations of the species. The potential value of cultivated yellowwood for conservation depends on the genetic diversity among cultivated trees compared to natural populations. Using nuclear microsatellite markers, we genotyped 180 yellowwoods from natural populations in Indiana, Missouri, Arkansas, and Kentucky, along with 61 trees from urban parks and landscapes in Indiana, Ohio, and Missouri. We found that, even when statistics were adjusted based on population size, the urban “population” had higher genetic diversity than any of the wild populations sampled, indicating that commercially-grown yellowwood is most likely a mixture of genotypes from isolated wild populations. We observed strong genetic differentiation among wild populations, and evidence for inbreeding in at least one of the wild populations. 相似文献
9.
Natalia Vizcaíno-Palomar Inés Ibáñez Marta Benito-Garzón Santiago C. González-Martínez Ricardo Alía 《New Forests》2017,48(3):363-379
Tree height-diameter allometry, the link between tree height and trunk diameter, reflects the evolutionary response of a particular species’ allocation patterns to above and belowground resources. As a result, it differs among and within species due to both local adaptation and phenotypic plasticity. These phenotypic variations in tree height-diameter allometry determine tree productivity, resistance and resilience to climate variation and, ultimately, the success of plant material used in restoration projects. We tested the effect of climate change and population origin on the phenotypic variation of tree allometry in four pine species at an early stage of development (ca. 11 years old) based upon data originated from multi-site provenance tests and planted along a wide climatic range in south-western Europe. For a representative sample of populations from each species, we used already-developed species-specific height-diameter allometric models to assess changes in allometry between present and future climatic conditions. We found that Pinus halepensis and Pinus pinaster were the most plastic species, while Pinus sylvestris and Pinus nigra showed negligible plastic responses. In addition, our models stressed that pine tree height-diameter allometry will change and phenotypic variation could increase, except in P. sylvestris, under future environmental conditions. For some of the species, this might allow the selection of phenotypes better suited to novel climatic conditions. These foreseeable changes in tree height-diameter allometry (among and within-species) could entail eco-evolutionary effects on the early forest plantation dynamics. Therefore, restoration and reforestation plans should consider these effects, as they may interfere with production and/or environmental goals. 相似文献
10.
Himalayan wild cherry (Prunus cerasoides), widely distributed in the Himalayas, was examined for viroid infection. Two of 15 samples collected from various regions of district Kangra, Himachal Pradesh, India gave positive amplification with primers specific for three fruit tree viroids. Sequencing of these two amplicons confirmed the presence of ASSVd in Himalayan wild cherry and share 99% identity. The isolates share 91–98% sequence identity with reported sequences from Greece of sweet cherry, Prunus avium, cv. Tragana Edissis (acc. no. FN376408 , FN376409 , FJ974069 ) and wild cherry, P. avium, originated from seedlings (acc. no. FJ974062 , FJ974063 and GQ249350 ). They also share 98% sequence identity with an Indian isolate of ASSVd (acc. no. FN547407 ). The present study reports the presence of ASSVd in Himalayan wild cherry. 相似文献
11.
林木群体交配系统研究进展 总被引:6,自引:0,他引:6
本文简要回顾了林木群体交配系统研究的历史,重点阐述了利用同工酶作为遗传标记对该问题的研究进展。目前开展交配系统研究的树种已超过52个,大部分研究集中在针叶树种,研究群体由原来的天然群体为主,到后来的天然群体与人工群体并重,转对人工群体的研究日渐加强。研究结果表明:针叶树种群体的异交率大都在90%左右,阔叶树种则相对较低,异交水平会因个体、冠层、群体密度、花量、花期不同而有所不同。根据上述情况,文章对今后的研究作了讨论,建议国内对同一领域开展研究的重点放在林木种子园中。 相似文献
12.
Chayma Rajeb Chokri Messaoud Hnia Chograni Afef Bejaoui Abdennacer Boulila Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2010,67(5):512-512
13.
The native cacao trees (Theobroma cacao L.) in south-eastern French Guiana represent a noteworthy fraction of the genetic diversity of this species. Several scientific surveys have led to the collection of numerous accessions, which provides an opportunity for investigating the pattern of genetic diversity in natural populations. Using a capillary electrophoresis genotyping system, we fingerprinted 189 wild trees in 18 natural populations. Based on the 15 loci SSR profiles, we analyzed the intra- and inter-population variation and their relationship with control clones. The global allelic richness was 4.87 alleles per locus, but was 2.4 on average within individual populations; gene diversity was 0.368 and observed heterozygosity was low (0.160). Major structuring was discovered in the metapopulation of French Guianan wild cacao trees (Fst = 0.20), which could be explained by the biological characteristics of the cacao tree and the climatic events that affected the Guianan forests in the Quaternary period. 相似文献
14.
15.
François Allal Georges Piombo Bokary A. Kelly John B. L. Okullo Massamba Thiam Ousmane B. Diallo George Nyarko Fabrice Davrieux Peter N. Lovett Jean-Marc Bouvet 《Agroforestry Systems》2013,87(5):1065-1082
The shea tree, Vitellaria paradoxa, is one of the most economically and culturally important indigenous tree species in the Sudano-Sahelian region. Its seeds contain a vegetable fat, internationally known as shea butter, which is widely used in edible, cosmetic and pharmaceutical sectors. Based on samples from 456 trees distributed in 17 locations across the species natural range from Senegal to Uganda, the fatty acid and tocopherol variation, and its relationship with geographic and climatic variables, was assessed in order to address the pattern and the origin of this variation across the natural range. Significant differences between Western and Eastern regions for oleic, stearic acid, saturated–unsaturated acid ratio and γ-tocopherol were identified that it is postulated maybe a result of genetic drift due to the evolutionary history of shea tree populations. Within regions the difference among stands was significant for most constituents; however the major part of the variation was observed among trees within stand (53–90 %). Relationships with climatic variables were not verified, weakening evidence for clinal variation hypotheses suggested by previous studies. 相似文献
16.
C. D. Campbell L. A. Mackie-Dawson E. J. Reid S. M. Pratt E. I. Duff S. T. Buckland 《Agroforestry Systems》1994,26(2):75-87
The use of a simple counting method using a borescope and minirhizotron system to study the interaction of roots of wild cherry trees (Prunus avium L) and pasture in an upland silvopastoral system is described. Operator variation was greatest when distinguishing different tree root categories (e.g. white, brown, woody) but was not significant in relation to total tree or grass root counts or species differences. Analysis of covariance was used to take these differences into account in a field trial using several operators. The seasonal patterns of tree and pasture root growth were different. Tree roots peaked in May before maximal shoot growth. The peak in pasture roots occurred two weeks earlier. Tree height growth was increased by the use of herbicides to control grass growth but this effect was only apparent during August when the soil was dry and when pasture root counts were reduced. 相似文献
17.
《Scandinavian Journal of Forest Research》2012,27(4):266-275
Seed orchards are the link from tree breeding to reforestation programs and are theoretically expected to function as closed, perfect populations, ensuring gain and diversity are consistently and predictively delivered as improved seed and seedlings. Seed orchard populations often deviate from panmixia due to fertility variation, reproductive asynchrony, and gene flow, leading to reduced seed crops genetic quality. Here, as a part of multiyear monitoring study, we used DNA fingerprinting (simple sequence repeat markers) to assess a Douglas-fir (Pseudotsuga menziesii) seed orchard's seed crop genetic quality (2009 seed crop). The studied seed crop was produced under ambient temperature (i.e. no reproductive phenology manipulation) and pollination was augmented by pollen from within orchard's pollen donors. DNA fingerprinting of the parental population (66 parents) along with 207 gametophyte (1n) – embryo (2n) pairs of random bulk sample of seed allowed parentage (maternal and paternal) assignment and the direct assessment of pollen contamination (0.18 ± 0.027) and selfing (0.17 ± 0.025) rates as well as parental (pollen, ovule and individual parent) gametic contribution was compared to a previous year's crop (2005). The extended reproductive phenology coupled with variable within-orchard pollen availability has created opportunities for both self and foreign pollen to be successful at various times resulting in the seemingly paradoxical scenario of high selfing and gene flow. These results (2005 and 2009) allowed comparison of seed orchard's crop management practices and are expected to provide scientific foundations to effective seed crops genetic quality improvement. 相似文献
18.
John C. Weber Carmen Sotelo Montes Tougiani Abasse Carlos R. Sanquetta Dimas A. Silva Sandra Mayer Graciela I. B. Muñiz Rosilei A. Garcia 《New Forests》2018,49(1):35-51
There is little information about variation in growth, wood density and carbon concentration in native tree and shrub species in Africa. This information is needed to make realistic projections about carbon sequestration of different species in different environments. Farmers manage natural regeneration of many native species in the drylands of Niger, so there is interest in carbon sequestration potential of the species. The objectives of this study were to determine: (1) if tree height, stem diameter, mean ring width, wood density and carbon concentration differ among five tree and shrub species (Combretum glutinosum, Combretum micranthum, Combretum nigricans, Guiera senegalensis, Piliostigma reticulatum) in Niger; (2) if variation within species is affected by land use type (parkland agroforests, woodlands), soil type (sandy, rocky), terrain type (temporarily flooded, flat, hill slope) and mean annual rainfall; and (3) if growth variables, wood density and carbon concentration are correlated in the five species. Environmental variables did not have strong effects on growth and wood variables of the species, and some effects differed among species. Height across species increased with mean annual rainfall. Stem diameter and mean ring width across species were greater in parkland agroforests than in woodlands. Carbon concentration was positively correlated with growth variables of four species, but was not correlated with wood density in most species. Correlations between wood density and growth differed in sign among some species. We conclude that above-ground carbon sequestration per tree probably increases with mean annual rainfall and is greater in parkland agroforests than in woodlands. 相似文献
19.
Simeon Springmann Robert Rogers Heinrich Spiecker 《Forest Ecology and Management》2011,261(3):764-769
Producing high value veneer wood requires that the tree bole be branch-free. This can be accomplished by natural or artificial pruning. Since wild cherry does not self prune well, pruning artificially is the only practical option. The study analysed the effect of conventional whorl-wise pruning and selective pruning, on height growth, diameter growth and secondary shoot development of wild cherry. Four pruning treatments were applied on cherry trees in summer 2007, one group of cherries was left unpruned to serve as a control: treatment C1 (upper 5 whorls left), C2 (upper 3 whorls left), S1 (removal of branches larger than 3 cm or with an angle to the stem < 40°), S2 (removal of branches larger than 2 cm or with an angle to the stem < 40°), N (unpruned). Data showed that height growth was not affected by pruning. In contrast, diameter growth at breast height of the C2 pruned cherry was reduced by approximately 5% (SE = 2.7%) in the year of pruning (trees were pruned in July). This pruning treatment produced significant (p = 0.028) nine percent less diameter growth than the control in the second year following pruning. The diameter increment of the C1 pruned trees with five whorls left after pruning and the selective pruned cherries were only about 4% (SE = 4.0%) smaller than the control after two years. This loss was statistically not significant. Analyses showed that on selective pruned trees the survival rate of secondary shoots was significantly reduced compared to those on whorl-wise pruned trees. Significant differences in the size of the secondary shoots were only found between the C1 and S1 (p < 0.05) pruned trees. We did not find differences in the total number of secondary shoots per tree among pruning treatments. Solely from a tree growth perspective, the moderate whorl-wise pruning treatment C1 and the selective prunings were equally effective in minimizing the reduction of diameter growth and are recommended in practice. However it was found that the survival of secondary shoots was reduced on selective pruned trees although the amount of pruning work needed in selective pruning was slightly greater than conventional moderate pruning. 相似文献
20.
Natalia Vizcaíno-Palomar Lorena Gómez-Aparicio Javier Pavón-García Carmen Bartolomé-Esteban Julio Álvarez-Jiménez Miguel A. Zavala 《European Journal of Forest Research》2014,133(6):1109-1119
Over the last few decades, abandonment of traditional management practices in Spain has led to widespread stand densification and has favoured the expansion of some forest species that previously exhibited more restricted ranges. Spanish juniper (Juniperus thurifera L.) woodlands are experiencing this phenomenon due to agricultural land abandonment and a decrease in the livestock pressure. Yet the main drivers underlying stand structure and dynamics at this novel scenario are poorly understood. In this study, we investigate the main biotic drivers of tree growth in a high-density stand of the dioecious J. thurifera at an early developmental stage (mean tree age of 32, ca. 50 years after land abandonment). Tree growth was measured by coring 299 individuals of different reproductive classes (male, female and non-reproductive). Neighbourhood models were used to assess the relative importance of tree size and neighbourhood competition on tree growth of each reproductive class in the study plot. We found that tree size had the strongest effect on tree growth, whereas the effect of intraspecific competition was negligible. We observed differences in growth patterns among reproductive classes along trunk diameter sizes. Thus, at smaller sizes, the three reproductive classes presented identical patterns of growth. However, at bigger sizes, females were the fastest growing individuals, followed by males and non-reproductive individuals. Overall, our results suggest that in young J. thurifera monospecific forests, where self-thinning processes may have not undergone yet, tree size and the reproductive class could play a relatively more important role than competition as drivers of tree growth. These findings constitute new information which contributes to understanding growth dynamics at early developmental stages in this dioecious species. Furthermore, our results provide guidelines for silvicultural managing, suggesting that at these young juniper stands thinning would likely not translate into enhanced growth on remnant trees. 相似文献