Tree Growth Parameters Research Articles

Application Research of Neural Expert System on Tree Growth Model

In order to simulate growth and development process of tree, then provide services for production management and scientific research, all kinds of tree growth models are constructed. The paper firstly considers a variety of factors affecting the growth and development of tree, then studies artificial intelligence knowledge such as neural network and expert system, uses the neural expert system to solve the acquisition and management of tree growth parameters, and design and develop tree growth management and expert system based on growth models, the models combine morphogenesis model of tree and knowledge model to provide comprehensive environmental control and management decision-making. Practice has indicated that the growth models of tree can reflect the growth of trees under different physiological and ecological conditions, and visual effect is very good.

Enhancing the regeneration of compacted forest soils by planting black alder in skid lane tracks

Soil compaction due to the use of heavy machinery for timber harvesting has become a widespread problem in forestry. However, only few studies deal with the regeneration of compacted forest soils. In the present study, we examined the potential of accelerating soil regeneration by planting black alder trees (Alnus glutinosa (L.) Gaertn.) in skid lane tracks. In 2003, seedlings were planted into the rut beds of severely compacted skid lanes in two Swiss forest sites. In addition, some of the ruts were filled with compost. In 2009 and 2010, we assessed the success of these measures by analysing physical parameters of soil structure (bulk density, total and coarse porosity and air permeability), root densities and tree growth. Tree growth was exceptionally strong on the skid lanes. Total and coarse soil porosity and air permeability showed significant increase in planted skid lanes as compared to untreated control subplots, approaching values found for untrafficked soil in the immediate vicinity. All soil physical parameters were closely correlated to root mass density. Compost application enhanced tree growth and soil structure regeneration on one site, but had a retarding effect on the other site. Planting black alders has great potential as an environmentally friendly measure to accelerate the structural regeneration of compacted forest soils in temperate humid climates.

Effects of Weed Control and Fertilization on Wood and Chemi-mechanical Pulp Properties of a Populus deltoides Clone

Weed control and fertilization usually lead to an increase in the growth rate of trees and, consequently, to a possible modification of the quality of the wood and its end products. The effect of weed control and fertilization practices were determined on tree growth parameters, wood density, fiber weight, fiber length, and chemical wood composition, as well as the chemi-mechanical pulp properties, for 8-year-old Populus deltoides `Delta Gold´ grown in Argentina. Four treatments belonging to a randomized complete block design trial were analysed: no weeding after planting (C), mechanical weed control (M), chemimechanical weed control (CHM), and fertilized + chemimechanical weed control (CHM-F). Soda-sulfite chemi-mechanical pulps were produced from said trees. Handsheets were prepared from the pulps, and their physical, mechanical, and optical properties were determined following international standards. Several wood and pulp properties were influenced by the studied silvicultural practices. In the context of this study, silvicultural treatments applied to Populus deltoides ‘Delta Gold’ (formerly ‘Stoneville 66’) trees can be applied to increase productivity (volume and fibrous output) without detrimental consequences to wood and pulp properties, except for a slight reduction in brightness.

Estimation of change of taper with age for Tectona grandis L. f. (Teak)

Taper is the change of diameter over a specified length along the tree stem, which varies not only byspecies and site type, but also by diameter at breast height (dbh), height and other tree growthparameters. Taper is important for the foresters to estimate the upper stem diameters especia!ly involume calculations.The main objective of the present study was to find out the variation of taper with different ages forTee/ana grandis L. f. (teak). For this reason, three teak plantations of 22, 27 and 35 years of agcwere selected from the Block Olin Kotagoda plantation, Ampara Forest Division. Selection of thesethree plantations from a single Block was done to minimise the effect of the site quality on treegrowth. Data were collected from randomly laid out 14 circular plots of 0.05 ha. The trees in sampleplots were measured for dbh, total height and sectional diameters at 5m and 10m along the stem.In order to estimate the taper variation, the equation developed by Kozak et af (1969) for Douglas firin Western Colombia was used. This equation is given below and it is considered as one of the bestmio?dels developed to estimate the upner stem tree diameters.mio?dels developed to estimate the upner stem tree diameters. 1 .~. 1 a: t dbh' =17" +hi(hl H)+b:(h- I H-);where d = diameter at height handH = total heightAt the first stage, the data were fitted to the selected equation separately for each age and theregression parameters were estimated separately without changing the basic structure of the originalequation.It was observed that the parameter b() and b , were positive values and increased from age 22 to 27and then decreased from that to age 35. TIle parameter b, was a negative value which decreasedfrom age 22 to 27 and then increased from that to age 35.When the results were examined further, it was observed that the taper is decreasing with the ageproving that the teak tree stems become more conical with the age, i.e., the diameter differenceincreases with age for a fixed length along the stem.

New evidence of solar variation in temperature proxies from Northern Fennoscandia

A new summer temperature proxy was built for northern Fennoscandia in AD 1000–2004 using parameters of tree growth from a large region, extending from the Swedish Scandes to the Kola Peninsula. It was found that century-scale (55–140year) cyclicity is present in this series during the entire time interval. This periodicity is highly significant and has a bi-modal structure, i.e. it consists of two oscillation modes, 55–100year and 100–140year variations. A comparison of the century-long variation in the northern Fennoscandian temperature proxy with the corresponding variations in Wolf numbers and concentration of cosmogenic 10Be in glacial ice shows that a probable cause of this periodicity is the modulation of regional climate by the secular solar cycle of Gleissberg. This is in line with the results obtained previously for a more limited part of the region (Finnish Lapland: 68–70°N, 20–30°E). Thus the reality of a link between long-term changes in solar activity and climate in Fennoscandia has been confirmed. Possible mechanisms of solar influence on the lower troposphere are discussed.

Effect of Crown Restriction on the Growth and Productivity of Sweet Cherries

The canopy of sweet cherry trees grown under cover has to be adapted to this growing system by canopy lowering, narrowing and renewing. Tree growth and productivity parameters were compared three years before and three years after canopy restriction (2006-2011) for cultivars ‘Iputj’ and ‘Krupnoplodnaya’ on rootstocks Gisela 4 and 5, Weiroot 154 and F 12/1 during the full production period. The largest trees with wider canopy both before and after canopy restriction were observed on rootstock F 12/1. Limiting pruning of trees on Weiroot 154 did not cause stronger shoot growth. On Weiroot 154 the canopy was slightly bigger than for trees on Gisela 4 and 5. Canopy volume was bigger for ‘Iputj’ before adaptation to the cover system than for ‘Krupnoplodnaya’. After canopy reduction the fruiting wood renewed slowly, and therefore, yield per tree even in the third year after pruning was almost three times less than before pruning. As cultivar ‘Krupnoplodnaya’ renewed fruiting wood faster, it was 5-37% more productive than ‘Iputj’. Productivity renewed more rapidly for trees on dwarfing rootstocks, especially on Gisela 5. The fruits of cultivar ‘Krupnoplodnaya’ were bigger both before and after pruning compared with ‘Iputj’. Of the tested rootstocks, F 12/1 was found to be not suitable for plantations under cover.

The current growth increment of pine tree stands comprising three different age classes

Abstract The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft’s class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMśw) and fresh coniferous (Bśw) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for each tree using Kraft’s criteria. The following characteristic were also measured: dbh of the trunk in two directions (N-S and W-E), and crown projection area on the basis of the characteristic tree crown points, projected using of a crown projector, characteristic points in tree crowns (7 to 14 on average). The actual height was determined after trees were felled. The following measurements of the single tree growing space were selected and determined: crown projection area - pk (m2), crown diameter - dk (m), Seebach’s growth space number - dk / d1.3, crown projection area to basal area ratio d 2 k / d 2 1.3, crown deflection coefficient dk / h, single tree space ppd = pk·h (m3). We assessed the strength of the relationships between tree growth parameters and tree growth space, crown length, relative crown length and slenderness. Both the age and dominance position of trees within the stand affected the growth increments. The strongest correlation among measured traits was between the 5-year volume increment and decreasing slenderness.

Allometry and partitioning of above- and below-ground biomass in farmed eucalyptus species dominant in Western Kenyan agricultural landscapes

Farmers in developing countries are one of the world's largest and most efficient producers of sequestered carbon. However, measuring, monitoring and verifying how much carbon trees in smallholder farms are removing from the atmosphere has remained a great challenge in developing nations. Devising a reliable way for measuring carbon associated with trees in agricultural landscapes is essential for helping smallholder farmers benefit from emerging carbon markets. This study aimed to develop biomass equations specific to dominant eucalyptus species found in agricultural landscapes in Western Kenya. Allometric relationships were developed by regressing diameter at breast height (DBH) alone or DBH in combination with height, wood density or crown area against the biomass of 48 trees destructively sampled from a 100 km2 site. DBH alone was a significant predictor variable and estimated aboveground biomass (AGB) with over 95% accuracy. The stems, branches and leaves formed up to 74, 22 and 4% of AGB, respectively, while belowground biomass (BGB) of the harvested trees accounted for 21% of the total tree biomass, yielding an overall root-to-shoot ratio (RS) of 0.27, which varied across tree size. Total tree biomass held in live Eucalyptus trees was estimated to be 24.4 ± 0.01 Mg ha−1, equivalent to 11.7 ± 0.01 Mg of carbon per hectare. The equations presented provide useful tools for estimating tree carbon stocks of Eucalyptus in agricultural landscapes for bio-energy and carbon accounting. These equations can be applied to Eucalyptus in most agricultural systems with similar agro-ecological settings where tree growth parameters would fall within ranges comparable to the sampled population.

Estimating the stormwater attenuation benefits derived from planting four monoculture species of deciduous trees on vacant and underutilized urban land parcels

This paper presents research that was undertaken to determine whether planting deciduous trees, using intensive tree planting schemes, on vacant and underutilized urban land provides significant hydrologic benefits. This work contributes to an ongoing discussion on how to use vacant and underutilized land productively, and may be important to land use decision-makers, whose policies support the use of green infrastructure for stormwater management. Tree growth parameters for four monoculture planting schemes were modeled (all trees had a 50.8mm caliper at planting) and included (i) 450 Ginkgo biloba, (ii) 92 Platanus×acerifolia, (iii) 120 Acer saccharinum, and (iv) 434 Liquidambar styraciflua, on a 1.6-acre parcel. i-Tree Hydro (formerly UFORE-Hydro) was used to derive a simplified Microsoft Excel-based water balance model to quantify the canopy interception potential and evaporation, based on 7 years (2002–2008) of historical hourly rainfall and mean temperature data in Hamilton, Ontario, Canada. This study revealed that three of the species responded similarly, while one species (L. styraciflua) performed significantly better with respect to total canopy storage potential and evaporation, capturing and evaporating 2.9m3/tree over the 7 years analyzed, or 1280m3 for the total tree stand of 434 trees. The analyses presented herein demonstrate that the tree canopy layer was able to intercept and evaporate approximately 6.5%–11% of the total rainfall that falls onto the crown across the 7 years studied, for the G. biloba, P.×acerifolia and A. saccharinum tree stands and 17%–27% for the L. styraciflua tree stand. This study revealed that the rate at which a species grows, the leaf area index of the species as it matures, and the total number of trees to be planted need to be determined to truly understand the behavior and potential benefits of different planting schemes; had the mature leaf area been used as the sole indicator of the stormwater attenuating potential for each species, the A. saccharinum would have been the selected species. Also, had attenuation and evaporation per unit of tree been the only measurement reported, the P.×acerifolia stand would have been deemed the best performing tree, attenuating and evaporating 8.1m3/tree. While the actual values presented herein may be uncertain because of a lack of locally-derived tree growth models, the approach described warrants further investigation.

Inventory Analysis of Milicia excelsa (Welw C. C. Berg.) in Ibadan (Ibadan Metropolis and University of Ibadan), Nigeria

A total of 78 existing stands of Milicia excelsa (Welw C. C. Berg.) in Ibadan Metropolis (IM) and University of Ibadan (UI) were evaluated in this study. All the accessible stands were evaluated for their height, diameter and canopy properties, while the relationships among the tree growth parameters were investigated. Density (Basal area) and stem volume of these tree stands in the study area were also computed while the collected data were analysed with the use of t-test statistical means. Results show that majority of trees fall within the 20-30 m height class and 100-200 cm diameter class, most of which are concentrated in UI. Furthermore, the tree stands in UI study area produced more tree density and stem volume than those in IM study area however, the difference was not significant (p>0.05). All the models generated were adequate and are recommended for M. excelsa volume assessment in the study area. The stand volume equations, which incorporated various tree growth variables, will enhance future yield prediction of the trees in the study areas since they provide quantitative basis for estimating stand growth parameters. It is believed that these models and volume prediction equations will enhance sound and informed management decisions and conservation measures for the remaining M. excelsa stands.

The role of roots in the resource economics spectrum

The role of roots in the resource economics spectrum

Use of compost to manage Fe nutrition of pear trees grown in calcareous soil

The aim of this study was to evaluate the effectiveness of soil applied compost in preventing Fe chlorosis of pear trees. The effect of the treatment was evaluated in field conditions on tree growth, nutritional status, yield, fruit quality and soil parameters. A 3-year long field trial was carried out in a mature commercial pear orchard of the cv. Abbé Fétel grafted on quince (Cydonia oblonga) BA29 located in the South Eastern Po Valley (Italy). In a completely randomized block design (5 replicates), including an untreated control, the following soil-applied treatments were compared: (i) Fe chelates (1.65g Fetree−1year−1 as Fe–EDDHA) applied yearly and split in two applications in spring; (ii) organic amendment (compost) applied yearly at a rate of 12kgfwtree−1 at bud break. Leaf Fe concentration and green color were increased by soil applied Fe chelate and, from the second season, by compost. Considering the whole experiment data of leaf Fe concentration and SPAD index showed a positive (P≤0.001) linear correlation (r=0.84). The supply of Fe chelate decreased significantly leaf K, Mn, fruit K and Cu concentration as well as fruit weight but raised tree yield. Compost showed intermediate values of tree crop load and higher fruit weight in comparison to Fe chelate. Iron deficiency reduced fruit sucrose and total carbohydrates concentration. Only compost addition stimulated soil microbial C biomass. Results demonstrate that composted organic wastes yearly applied improved Fe nutrition of pear trees grown in calcareous soils.

Aboveground Biomass Dynamics in the Amazonian Rainforest under Influence of Reduction in Rainfall

Exchange of biomass between the ecosystem and the atmosphere plays an important role in regional and global carbon cycles that have a major impact on biodiversity. This study evaluated the effect of reduction in rainfall on the aboveground biomass in an Amazonian rainforest. Data for this study were obtained from the “Long-term drought impact on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment (ESECAFLOR)” which was a subproject of Large Scale Biosphere Atmosphere Experiment in Amazon forest (LBA), carried out in terra firma rainforest in Caxiuana National Forest, Para, Brazil. The experimental design entailed two experimental sites each with one hectare of natural forest: control TFE (a simulated soil drought or ‘throughfall exclusion’ experiment) under normal conditions of climate and treatment TFE with rainfall exclusion of about 50%. The tree growth parameters employed in the study were based on monthly data from the experimental period from January 2005 to May 2009. Results indicated that a decrease in rainfall significantly affected the tree growth parameters, resulting in a decrease of biomass (21.1 t ha-1 year-1) and basal area (1.04 m2 ha-1 year-1). The Amazonian rainforest may become increasingly vulnerable to higher background tree mortality rates in response to drought events, such as El Nino.

The impact of climate change on the growth of tropical agroforestry tree seedlings

Several studies have been conducted on the response of crops to greater concentrations of atmospheric CO2 (CO2 fertilization) as a result of climate change, but only few studies have evaluated this effect on multipurpose agroforestry tree species in tropical environments. The objectives of this study were to quantify differences in growth parameters and in leaf carbon (C) and nitrogen (N) concentrations of Cedrela odorata L. and Gliricidia sepium (Jacq.) Walp. seedlings under current ambient temperature (32°C daytime, 22°C night time) and CO2 (360 ppm) (AMB); CO2 fertilization (800 ppm, 32°C daytime, 22°C night time) (fCO2); elevated ambient temperature (360 ppm, 34°C daytime, 25°C night time) (TEMP); and a combination of elevated temperature (32°C daytime, 22°C night time) and CO2 fertilization (800 ppm) (TEMPxfCO2). Results showed significant differences (P < 0.05) in seedling growth parameters (seedling height, number of stem leaves, leaf area ratio, shoot and root biomass, and shoot/root ratio) between treatments for both tree species. The greatest increases in growth parameters occurred in the TEMP and TEMPxfCO2 treatments compared to the AMB treatment for both tree species. However, growth parameters were significantly lower (P < 0.05) in the fCO2 treatment compared to that of the AMB treatment. Leaf N concentration was 1.1 to 2.1 times lower (P < 0.05) in all treatments when compared to current ambient conditions (AMB) in both tree species, but no significant changes in leaf C concentrations were observed. Results from our study suggested that fCO2 had the greatest negative impact on tree growth parameters, and leaf N concentrations were affected negatively in all treatments compared to current ambient conditions. It is expected that such changes in growth parameters and plant N content may impact the long-term cycling of nutrients in agroforestry systems.

Lophodermium needle cast, insect defoliation and growth responses of young Scots pines in Estonia

SummaryUsing a retrospective approach, based on historical needle cast disease and insect pest records, data series of needle losses (reconstructed by the use of the needle trace method), tree growth parameters and meteorological data were studied to determine the impact of the appropriate pointer (epidemic or calamity) years on the annual radial and height increment of 46 sample trees in six Scots pine (Pinus sylvestris) stands in Estonia from 1887 to 2006. First, the needle cast epidemics during the last 120 years were retrospectively determined, with resulting 4.6 epidemics per decade as a mean frequency. If the sum of precipitation from May to August reached 300 mm (the mean of 12 epidemic years studied: 361 ± 15 mm), an epidemic of needle cast caused byLophodermium seditiosummight follow the next year in young plantations. For insect defoliators, similarly clear triggering threshold values of precipitation or temperature could not be determined, although dry and warm summers and mild winters supported the calamities. We separately detected that both larger needle losses and growth reductions in trees related to Lophodermium needle cast epidemic years lasted until the same age of pines, 22–24 years, but for insect pest (diprinoid sawflies) calamity years the growth reduction lasted longer. The relevance of these findings for the prediction of Lophodermium needle cast epidemics is briefly discussed.

Effects of Fertilizer and Low Rates of Imidacloprid on Adelges tsugae (Hemiptera: Adelgidae)

Healthy hemlock trees, Tsuga canadensis (L.) Carrière, and hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), populations should favor retention and population growth of adelgid predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae (Sasaji & McClure) (Coleoptera: Coccinellidae). Eastern hemlock trees between 15 and 38 cm diameter at breast height (dbh) were treated with 0, 10, or 25% of 1.5 g imidacloprid (Merit 75 WP) per 2.5 cm dbh and were either fertilized or not, in a 3 by 2 factorial design. After 2 yr, imidacloprid reduced the numbers of ovisacs and eggs found on trees in a dosage-dependent manner, while enhancing tree growth parameters such as new shoots or needles and the length of new shoots. Fertilized trees had greater adelgid fecundity, which was positively correlated with total foliar N in both winter generations. In February 2009 (27 mo after imidacloprid treatment), higher imidacloprid dosages to unfertilized trees resulted in reduced adelgid fecundity. Concentrations of N, P, and K were higher in the foliage of trees treated with insecticide, whereas foliar aluminum concentrations were consistently lower in trees with higher insecticide dosages. Trees treated with low rates of imidacloprid were healthier than untreated trees, but only trees treated with the 0.1 x dosage had sufficient adelgids to possibly sustain predators over extended periods.

The influence of bearing cycles on olive oil production response to irrigation

Water requirements for olive oil production and the effects of deficit irrigation were determined while considering the relative fruit loads on trees occurring as a result of biennial bearing cycles. Two Israeli olive (Olea europaea) varieties (Barnea and Souri) were evaluated for growth and yield parameters in a 4-year field study where five relative irrigation rates were applied. Increasing irrigation increased stem water potential, vegetative growth, and olive fruit yield with the increases tapering off at application rates reaching 75–100% of potential crop evapotranspiration. Tree water status, growth, and fruit characteristic parameters were highly affected by both fruit load and by irrigation level. Oil yield increases as a function of increased irrigation were initiated for each cultivar only following an ‘off’ season when the treatments lead to higher vegetative growth. The increased oil yields as a function of increased irrigation were primarily explained by higher tree-scale capacity for carrying fruit, especially as irrigation alleviated measureable water stress. For the Barnea cultivar in ‘on’ years, a secondary effect due to increased oil per fruit as irrigation increased was evident, particularly at the higher application rates.

GREENHOUSE PLASTIC FILMS CAPABLE OF MODIFYING THE SPECTRAL DISTRIBUTION OF SOLAR RADIATION

The aim of this paper was to investigate the radiometric properties of innovative covering films for protected cultivation capable of modifying the spectral distribution of the transmitted radiation and thus the vegetative activity. Two photoselective films, three photoluminescent films and one low-density polyethylene film were used as greenhouse coverings for cherry trees and peach trees, grown in pots. The photoselective films were characterised by a reduction of the R/FR ratio in comparison to the natural solar radiation. Tree growth parameters, such as the apical shoot of cherry trees and the shoot of peach trees, were monitored. Different responses to vegetative activities were observed under the films, depending on the species, with a higher shoots growth rate in the peach with respect to the cherry. The photoselective film characterised by the lowest R/FR ratio significantly enhanced the growth of cherry and peach trees in comparison to the trees cultivated under the other greenhouse films

Divergence pitfalls in tree-ring research

,andinto degrees Celsius—forming the cornerstone for proxy reconstructions (Cookand Kairiukstis 1990). The specific subject of the Loehle (2009) contribution is onnon-linear calibration techniques, which have been considered when proxy data in-dicate inconsistent responses to medium and extreme temperature deviations. Non-linear calibration has a long-standing history in tree-ring research (see Fritts 1976 foran introduction), and variants of non-linear response models have been applied in avariety of tree-ring analyses over the past decades (e.g., Carrer and Urbinati 2001;Fritts 1969; Graumlich and Brubaker 1986; Woodhouse 1999). So, while approachesto tackle non-linear tree-ring/climate associations are relevant when dealing withproxy data, it is, however, the motivation that called for re-attention to thesetechniques that is of particular interest: the divergence phenomenon (DP) in tree-ring research.DP was first described over a decade ago by Jacoby and D’Arrigo (1995)andsince then has been reported from a variety of sites mainly concentrated towardsthe Northern Hemisphere boreal forest zone (see D’Arrigo et al. 2008 for a review).DP effectively describes a disassociation of late twentieth century (typically post-1960) tree growth parameters, such as ring width or maximum latewood density,from regional temperature trends. This disassociation does not necessarily comprisea weakening of the high-frequency climate signal. That is, inter-annual tree-ringvariation may be predominantly controlled by temperatures, but the long-term

The development of even-aged plantation forests: an exercise in forest stand dynamics

In this paper we present a field-based practical exercise that allows students in forestry, ecology and natural resources to develop their understanding of forest stand dynamics. The exercise involves measurement of key tree growth parameters in four even-aged, single-species plantation stands of different age but occupying sites with similar soil and environmental characteristics. The selected stands represent key stages in stand development, from establishment to rotation age for maximum fibre production. In the field, students work in small teams to gather data from an equal number of plots within each stand. Tree parameters include top height, crown diameter, live crown ratio and diameter at breast height. In addition, information on stand density and understorey vegetation is collected. Plot size and number can be varied to suit the constraints of class size and available time, though circular plots of 100m2 are recommended. In the classroom, data are pooled and analysis focuses on presenting tree and vegetation changes through time. The simplest way of interpreting the data is to prepare graphs and charts for each of the parameters, though more advanced statistical interpretations are possible. The project as outlined here can be modified to meet the needs of different groups, and has been successfully used in undergraduate teaching of silviculture and forest ecology, as well as in postgraduate courses in natural resources management.