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Diameter Growth (diameter + growth)
Terms modified by Diameter Growth Selected AbstractsA medium to enhance identification of Septoria musiva from poplar cankersFOREST PATHOLOGY, Issue 3 2002J. C. STANOSZ A series of experiments was conducted to determine the relative tolerance in vitro of an isolate of Septoria musiva (a fungus that causes a severely damaging stem canker disease of poplars) for selected chemicals. Inhibition of diameter growth of this fungus on a V-8 vegetable juice-based medium with captan, chlorothalonil, iprodione, mancozeb and streptomycin sulphate at concentrations, respectively, of 50, 1, 10, 10, and 100 mg l,1 was relatively low compared to inhibition of eight other fungi cultured from cankers on poplars. In addition, the presence of captan stimulated profuse sporulation of the fungus. These properties assisted in the identification of S. musiva from cankers resulting from artificial inoculation of poplar branches in the field. Un milieu de culture pour aider à l'identification de Septoria musiva isolé de chancres sur peuplier Un isolat de Septoria musiva, champignon responsable de chancres de tronc sur peupliers, àété testéin vitro pour sa tolérance à un certain nombre de substances. L'inhibition de la croissance en diamètre a été déterminée sur milieu V8 additionné de captan, chlorothalonil, iprodione, mancozèbe et sulfate de streptomycine aux concentrations respectives de 50, 1, 10, 10, et 100 mg par litre; l'inhibition était relativement faible comparée à celle de huit autres champignons isolés de chancres de peuplier. La présence de captan stimulait la sporulation du champignon. Ces propriétés ont aidéà l'identification du S. musiva réisoléà partir de chancres obtenus au champ par inoculation artificielle de branches de peuplier. Ein Medium zur Verbesserung der Identifikation von Septoria musiva aus Pappelkrebsen Es wurde eine Serie von Experimenten zur Bestimmung der relativen Toleranz eines Septoria musiva Isolats (ein Erreger ausserordentlich schädlicher Stammkrebse an Pappeln) gegenüber ausgewählten Chemikalien durchgeführt. Das Wachstums des Pilzes auf einem auf V-8 Gemüsesaft basierenden Medium mit 50 mg l,1 Captan, 1 mg l,1 Chlorothalonil, 10 mg l,1 Iprodion, 10 mg l,1 Mancozeb und 100 mg l,1 Streptomycinsulfat wurde im Vergleich zum Wachstum von acht anderen Pilzarten, die ebenfalls aus Pappelkrebsen isoliert wurden, nur schwach gehemmt. Zudem regte Captan den Pilz zu intensiver Sporulation an. Als hilfreich erwiesen sich diese Eigenschaften in Feldversuchen bei der Identifikation von S. musiva aus Krebsen, die sich nach künstlicher Inokulation von Pappelzweigen entwickelten. [source] Testing liana cutting and controlled burning as silvicultural treatments for a logged forest in the eastern AmazonJOURNAL OF APPLIED ECOLOGY, Issue 6 2001Jeffrey J. Gerwing Summary 1In the eastern Brazilian Amazon, logged forests frequently include patches where liana density is particularly high. In these so-called liana tangles, competition from lianas is predicted to reduce tree growth significantly, thus effectively impeding future timber production. To begin to develop a silvicultural strategy for these patches, the impact of liana cutting and controlled burning on liana density, tree growth and tree regeneration in liana-dominated patches was investigated in a logged forest in the eastern Brazilian Amazon. 2The two treatments (liana cutting and controlled burning) and a control were installed in 40 × 40-m plots in a randomized complete block design of six blocks. Treatments were conducted during October 1997, and tree diameter growth and mortality, canopy cover, regeneration and liana density were monitored over 2 years. 3Mean mortality following burning was significantly higher for lianas (79%) than for trees (48%), as was the mean coppicing rate of top-killed stems (42% for lianas vs. 20% for trees). Coppicing combined with some recruitment from seed resulted in liana densities in the burned plots returning to 70% of the values in the control plots only 2 years post-treatment. 4Canopy light transmittance, estimated from hemispherical canopy photographs taken at 1 m above the ground, increased significantly from c. 4% in controls to 8% in cut and 12% in burned treatments, and these differences persisted over the 2-year study period. 5In the absence of silvicultural intervention, mean tree diameter increments were low (1·3 mm year,1), suggesting that the successional transition to higher stature forest was occurring very slowly. Each of the treatments resulted in a more than doubling of mean annual tree growth (3 and 2·8 mm year,1 for liana-cut and burned treatments, respectively). The treatments also significantly reduced the occurrence of trees that showed no growth over the study period, from 56% in controls to 30% in cut and 32% in burned treatments. 6The results of this study suggest that although burning resulted in increased tree growth, rapid recolonization of surviving trees by lianas and the high vulnerability of burned stands to unwanted repeat burns are likely to cancel out any of the possible benefits of controlled burning as a silvicultural treatment for liana-dominated patches. Liana cutting, on the other hand, showed promise and its adoption as part of a larger strategy for the recuperation of the timber production potential of logged tropical forests seems warranted. [source] Effects of climate on the growth of exotic and indigenous trees in central ZambiaJOURNAL OF BIOGEOGRAPHY, Issue 1 2005E. N. Chidumayo Abstract Aim, Climate change has far-reaching effects on species and ecosystems. The aims of this study were to determine how climate factors affect the growth pattern of indigenous and exotic trees in Zambia and to predict tree growth responses to a warmer climate with the use of mathematical models. Location, Two savanna sites in central Zambia. Methods, Diameter at breast height (1.3 m above ground, d.b.h.) of 91 permanently marked trees belonging to three indigenous and four exotic species was measured fortnightly for periods of 1,2 years from 1998 to 2003. Correlation and regression analysis was used to determine the effect of climate factors (minimum, maximum and average temperature and rainfall) on monthly daily d.b.h. increment of each species. Regression models were used to predict the growth behaviour of trees under a 0.5 °C warmer climate. Results, Interactions between temperature and rainfall explained 60,98% of the variation in d.b.h. increment in all the tree species, except the exotic Eucalyptus grandis. For deciduous species, stem expansion was delayed by 2,12 weeks following leaf-flush and d.b.h. increment peaked during the rainy season. Evergreen and deciduous species could not be separated on the basis of annual d.b.h. increment because the higher growth rates of deciduous species compensated for the shorter growing period. Mathematical models predicted slight changes in d.b.h. growth pattern under a 0.5 °C warmer climate in five of the seven species. Significant changes in d.b.h. growth patterns were predicted in the indigenous Bridelia micrantha and exotic Gmelina arborea under a warmer climate. However, models failed to adequately represent potential soil water stress that might result from changes in tree growth patterns and a warmer climate. Main conclusions, Climate factors explained a large proportion of the variation in diameter growth of both indigenous and exotic trees, rendering it possible to model tree growth patterns from climate data. Tree growth models suggest that a rise in temperature of 0.5 °C is unlikely to induce significant changes in the growth behaviour of the majority of the studied species. However, because the growth behaviour of some species may be substantially affected by climate change, it is recommended that strategies for the future production of such climate-sensitive trees should incorporate aspects of climate change. [source] Effects of size, competition and altitude on tree growthJOURNAL OF ECOLOGY, Issue 5 2007DAVID A. COOMES Summary 1,Understanding the factors influencing tree growth is central to forest ecology because of the significance of growth to forest structure and biomass. One of the simplest, yet most controversial growth models, proposed by Enquist and colleagues, predicts that stem-diameter growth scales as the one-third power of stem diameter. Recent analyses of large-scale data sets have challenged the generality of this theory and highlighted the influence of resource competition on the scaling of growth with size. 2Here we explore the factors regulating the diameter growth of 3334 trees of mountain beech (Nothofagus solandri var. cliffortioides) growing in natural single-species forests in New Zealand. Maximum-likelihood modelling was used to quantify the influences of tree size, altitude, the basal area of taller neighbours (BL) and the basal area of all neighbours (BT) on growth. Our interpretation of the models assumed that taller neighbours compete for light whereas all neighbours compete for nutrients. 3The regression analyses indicate that competition for light has a strong influence on the growth of small trees, whereas competition for nutrients affects trees of all sizes. These findings are consistent with experimental manipulation studies showing that competition for light and nutrients inhibits the growth of small mountain beech trees, and fertilizer application studies showing that nitrogen limits the growth of large trees. 4Tree growth declined with altitude. The regression analyses suggest that the intensity of light competition also declines with altitude, when trees with similar BT and BL values were compared along the gradient. These results are consistent with observations that trees become stunted and have more open canopies at high altitudes. 5Our study is the first to build the effects of competition and environment into Enquist's model of tree growth. We show that competitive interactions alter the scaling of mean growth rate with size, whereas altitude does not influence the scaling of potential growth rate with size. [source] Soil properties and tree growth along an altitudinal transect in Ecuadorian tropical montane forestJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2008Wolfgang Wilcke Abstract In tropical montane forests, soil properties change with increasing altitude, and tree-growth decreases. In a tropical montane forest in Ecuador, we determined soil and tree properties along an altitudinal transect between 1960 and 2450 m asl. In different vegetation units, all horizons of three replicate profiles at each of eight sites were sampled and height, basal area, and diameter growth of trees were recorded. We determined pH and total concentrations of Al, C, Ca, K, Mg, Mn, N, Na, P, S, Zn, polyphenols, and lignin in all soil horizons and in the mineral soil additionally the effective cation-exchange capacity (CEC). The soils were Cambisols, Planosols, and Histosols. The concentrations of Mg, Mn, N, P, and S in the O horizons and of Al, C, and all nutrients except Ca in the A horizons correlated significantly negatively with altitude. The C : N, C : P, and C : S ratios increased, and the lignin concentrations decreased in O and A horizons with increasing altitude. Forest stature, tree basal area, and tree growth decreased with altitude. An ANOVA analysis indicated that macronutrients (e.g., N, P, Ca) and micronutrients (e.g., Mn) in the O layer and in the soil mineral A horizon were correlated with tree growth. Furthermore, lignin concentrations in the O layer and the C : N ratio in soil affected tree growth. These effects were consistent, even if the effect of altitude was accounted for in a hierarchical statistical model. This suggests a contribution of nutrient deficiencies to reduced tree growth possibly caused by reduced organic-matter turnover at higher altitudes. [source] Genetic parameters and QTL analysis of ,13C and ring width in maritime pinePLANT CELL & ENVIRONMENT, Issue 8 2002O. Brendel Abstract Classical quantitative genetics and quantitative trait dissection analysis (QTL) approaches were used in order to investigate the genetic determinism of wood cellulose carbon isotope composition (,13C, a time integrated estimate of water use efficiency) and of diameter growth and their relationship on adult trees (15 years) of a forest tree species (maritime pine). A half diallel experimental set-up was used to (1) estimate heritabilities for ,13C and ring width and (2) to decompose the phenotypic ,13C/growth correlation into its genetic and environmental components. Considerable variation was found for ,13C (range of over 3,) and for ring width (range of over 5 mm) and significant heritabilities (narrow sense 0·17/0·19 for ,13C and ring width, respectively, 100% additivity). The significant phenotypic correlation between ,13C and ring width was not determined by the genetic component, but was attributable to environmental components. Using a genetic linkage map of a full-sib family, four significant and four suggestive QTLs were detected for ,13C, the first for ,13C in a forest tree species, as far as known to the authors. Two significant and four suggestive QTLs were found for ring width. No co-location of QTLs was found between ,13C and growth. [source] Vegetation Control Treatments to Favor Naturally Regenerated Betula alleghaniensis Saplings Following Seed-Tree Cut: Sapling Monitoring Two Years after TreatmentRESTORATION ECOLOGY, Issue 4 2007Daniel Bouffard Abstract Control of competing vegetation is recommended to ensure successful Yellow birch (Betula alleghaniensis Britton) regeneration within juvenile stands that do not sustain high enough sapling densities of this species. Four contrasting vegetation control treatments were tested to determine their effect on the growth and vigor of eight-year-old B. alleghaniensis saplings regenerating after final cutting of a shelterwood seed cut. Vegetation control treatments were TC (total circular removal), PC (circular removal of codominant competing vegetation), TS (total semicircular removal on 180° section), and NC (no vegetation control). Two years after treatment application, diameter growth significantly improved in response to vegetation control treatments, whereas sapling height growth did not. This pattern of biomass allocation was directly related to sapling etiolation, which increased with decreasing severity of vegetation removal. As a result, application of vegetation control, especially TC and PC treatments, was valuable in reducing signs of stress in saplings. However, increasing the severity of vegetation removal also made saplings more conspicuous to herbivores, which increased browsing, especially in the TC and PC treatments. Browsing was sufficient in some plots of the TC and PC treatments to overcome the vigor and diameter growth enhancements observed when browsing was negligible. In contrast to the TC and PC treatments, the TS treatment kept browsing very low while largely removing competition. The results suggest that B. alleghaniensis saplings established after final cutting of a shelterwood seed cut do take advantage of vegetation control treatments, but the decision to apply these treatments must include consideration of local herbivore population densities. [source] Influence of canopy tree size on stand basal area may reflect uncoupling of crown expansion and trunk diameter growthAUSTRAL ECOLOGY, Issue 2 2003Christopher H. Lusk Abstract A recent article by Midgley and colleagues suggests that large trees give rise to inordinately high stand basal areas because they pack canopy space more efficiently than smaller trees. We argue that this phenomenon bears more relation to the fact that diameter increment is not necessarily accompanied by significant crown expansion during all stages of a tree's life. Using data from a canopy tree population in an old-growth temperate forest, we found that crown area scaled as roughly the 3/5 power of trunk basal area. Rather than reflecting fixed scaling laws, we suggest that this pattern arises because of limited opportunities for crown expansion in dense stands. Old canopy trees in dense stands can thus accumulate large basal areas without occupying a commensurately large canopy area. [source] Effects of Season, Rainfall, and Hydrogeomorphic Setting on Mangrove Tree Growth in MicronesiaBIOTROPICA, Issue 2 2007Ken W. Krauss ABSTRACT Seasonal patterns of tree growth are often related to rainfall, temperature, and relative moisture regimes. We asked whether diameter growth of mangrove trees in Micronesia, where seasonal changes are minimal, is continuous throughout a year or conforms to an annual cycle. We installed dendrometer bands on Sonneratia alba and Bruguiera gymnorrhiza trees growing naturally within mangrove swamps on the islands of Kosrae, Federated States of Micronesia (FSM), Pohnpei, FSM, and Butaritari, Republic of Kiribati, in the eastern Caroline Islands of the western Pacific Ocean. Trees were remeasured monthly or quarterly for as long as 6 yr. Annual mean individual tree basal area increments ranged from 7.0 to 79.6 cm2/yr for all S. alba trees and from 4.8 to 27.4 cm2/yr for all B. gymnorrhiza trees from Micronesian high islands. Diameter increment for S. alba on Butaritari Atoll was lower at 7.8 cm2/yr for the one year measured. Growth rates differed significantly by hydrogeomorphic zone. Riverine and interior zones maintained up to seven times the annual diameter growth rate of fringe forests, though not on Pohnpei, where basal area increments for both S. alba and B. gymnorrhiza were approximately 1.5 times greater in the fringe zone than in the interior zone. Time-series modeling indicated that there were no consistent and statistically significant annual diameter growth patterns. Although rainfall has some seasonality in some years on Kosrae and Pohnpei and overall growth of mangroves was sometimes related positively to quarterly rainfall depths, seasonal diameter growth patterns were not distinctive. A reduced chance of moisture-related stress in high-rainfall, wetland environments may serve to buffer growth of Micronesian mangroves from climatic extremes. [source] | ||||||||||