scholarly journals Relationships between understory vegetation and hybrid poplar growth and size in an operational plantation

2016 ◽  
Vol 92 (04) ◽  
pp. 469-476 ◽  
Author(s):  
Jessica S. J. Grenke ◽  
S. Ellen Macdonald ◽  
Barb R. Thomas ◽  
Carly A. Moore ◽  
Edward W. Bork
Keyword(s):  
Positive Impact ◽  
Perennial Grass ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Understory Vegetation ◽  
Tree Size ◽  
Perennial Grasses ◽  
Stem Volume ◽  
Competitive Effects ◽  
Volume Increment

The effect of varying composition and abundance of neighbouring herbaceous vegetation on tree growth in commercial hybrid poplar plantations remains unclear. We evaluated relationships between tree stem volume, volume increment, and the abundance of various growth forms (perennial grasses, legumes, and perennial forbs excluding legumes) adjacent to the tree base in four-year-old plantation trees under conditions protected from ungulate herbivory. Associations between tree metrics and the understory revealed that perennial grasses consistently reduced tree size and current annual volume growth, and the negative effects of grasses were made worse by increasing legume cover. Under little to no perennial grass cover however, the presence of legumes had a positive impact on tree size and growth, suggesting net facilitative versus competitive effects. The pesence of forbs other than legumes led to no apparent competitive effects after four years, and may instead signify the absence of more competitive understory vegetation, particularly grasses. While final modelled relationships showed that the understory accounted for a limited amount of variance in tree volume (R2=0.10) and volume increment (R2=0.09) in four-year-old trees, these results nevertheless have implications for the development of silvicultural prescriptions targeting understory vegetation in order to maximize commercial hybrid poplar plantation yields.

Crown structure and growth efficiency of red spruce in uneven-aged, mixed-species stands in Maine

1998 ◽  
Vol 28 (8) ◽  
pp. 1233-1240 ◽  
Author(s):  
Douglas A Maguire ◽  
John C Brissette ◽  
Lianhong Gu
Keyword(s):  
Leaf Area ◽  
Volume Growth ◽  
Growth Efficiency ◽  
Tree Size ◽  
Red Spruce ◽  
Stem Volume ◽  
Mixed Species ◽  
Individual Tree ◽  
South Central ◽  
Tree Leaf

Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i)estimate the amount of foliage held by individual trees from sapwood cross-sectional area and (ii)define the relationship between stem volume growth and three variables: total foliage area, relative position in the stand, and the degree of past suppression. A model that included variables representing tree size (or relative social position) and degree of past suppression (live branch whorls per unit crown length) indicated that stem volume growth first increased but later decreased over leaf area when other variables were held constant. Growth efficiency declined with increasing tree leaf area, although greater height and diameter enhanced growth efficiency and greater past suppression diminished growth efficiency. The decline in growth efficiency with greater leaf area likely is attributable to one or several of the factors previously identified as contributing to growth declines in mature, even-aged stands.

Growth and foliar nutrition of juvenile western hemlock and western redcedar plantations on low- and medium-productivity sites on northern Vancouver Island: response to fertilization and planting density

2007 ◽  
Vol 37 (12) ◽  
pp. 2587-2599 ◽  
Author(s):  
R. W. Negrave ◽  
C. E. Prescott ◽  
J. E. Barker
Keyword(s):  
Volume Growth ◽  
Western Hemlock ◽  
Planting Density ◽  
Stem Volume ◽  
Thuja Plicata ◽  
Limiting Factor ◽  
Western Redcedar ◽  
Stand Volume ◽  
Reduced Height ◽  
Volume Increment

A factorial trial was established to examine the effects of planting density and fertilization on the growth of western redcedar ( Thuja plicata Donn ex D. Don) and western hemlock ( Tsuga heterophylla (Raf.) Sarg.) on nutrient-poor (CH) sites and nutrient-medium (HA) sites. Two levels of NPK fertilization were crossed with three levels of planting density (500, 1500, and 2500 stems/ha). Fifteen years after establishment and 10 years after the last fertilizer application, height, individual stem volume increment, stand volume, 5 year periodic annual increment (PAI), and 5 year periodic height increment were all increased by fertilization. Fertilization of CH sites increased annual stand volume increment by 753%–2552% and 122%–209% for hemlock and cedar, respectively; fertilization of HA sites increased PAI by 94%–264%. Volume growth response to fertilization was greater on HA than on CH sites. Increasing stand density reduced height growth on CH sites but not on HA sites. These results suggest that competition for nutrients can be a significant growth-limiting factor even before canopy closure occurs and that treatment of ericaceous sites may not be justified by productivity increases.

Tree size, biomass, and volume growth of twelve 34-year-old Ontario jack pine provenances

1985 ◽  
Vol 15 (6) ◽  
pp. 1129-1136 ◽  
Author(s):  
S. Magnussen ◽  
V. G. Smith ◽  
C. W. Yeatman
Keyword(s):  
Volume Growth ◽  
Tree Height ◽  
Stem Bark ◽  
Jack Pine ◽  
Tree Size ◽  
Stem Volume ◽  
Strong Negative Correlation ◽  
Stem Wood ◽  
Volume Production ◽  
Branch Wood

Tree size and aboveground biomass in twelve 34-year-old Ontario jack pine (Pinusbanksiana Lamb.) provenances growing at Petawawa National Forestry Institute (Chalk River, Ontario) was negatively correlated with latitude of origin. The best provenance exceeded the local provenance in tree height and diameter by approximately 10%. The pattern of geographical variation was stable over time, making general and sound predictions of provenance growth based on juvenile performance feasible. Persistent differences among some geographically close provenances indicated the potential for genetic improvement by selecting the best populations within site regions. The results demonstrated have important implications for jack pine breeding and improvement strategies at the provenance level. The provenance averages of aboveground ovendry weight per tree ranged from 44 to 79 kg. The aboveground tree biomass was distributed as follows in seven analyzed provenances: stem wood, 78%; stem bark, 8%; branch wood, 8%; needles, 5%; cones, 1%. Variation in average stemwood mass among provenances was less than the variation in average stem volume because of a strong negative correlation on a single tree basis between stem volume and stem wood density. The mean annual volume and biomass accretion per hectare in the best provenances averaged 10 m3 and 4 t, respectively. Total stem volume production per hectare varied exponentially with tree height. Mean annual stem volume increment of the best provenances exceeded that of the slowest growing provenances by 22–40%.

scholarly journals Empowering Forest Owners with Simple Volume Equations for Poplar Plantations in the Órbigo River Basin (NW Spain)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 124
Author(s):  
Roberto Blanco ◽  
Juan A. Blanco
Keyword(s):  
River Basin ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Forest Owners ◽  
Individual Tree ◽  
Average Growth ◽  
Volume Increment ◽  
Annual Volume ◽  
Poplar Plantations ◽  
Volume Equations

Hybrid poplar plantations are becoming increasingly important as a source of income for farmers in northwestern Spain, as rural depopulation and farmers aging prevent landowners from planting other labor-intensive crops. However, plantation owners, usually elderly and without formal forestry background, lack of simple tools to estimate the size and volume of their plantations by themselves. Therefore, farmers are usually forced to rely on the estimates made by the timber companies that are buying their trees. With the objective of providing a simple, but empowering, tool for these forest owners, simple equations based only on diameter were developed to estimate individual tree volume for the Órbigo River basin. To do so, height and diameter growth were measured for 10 years (2009–2019) in 404 trees growing in three poplar plantations in Leon province. An average growth per tree of 1.66 cm year−1 in diameter, 1.52 m year−1 in height, and 0.03 m3 year−1 in volume was estimated, which translated into annual volume increment of 13.02 m3 ha−1 year−1. However, annual volume increment was different among plots due to their fertility, with two plots reaching maximum volume growth around 11 years since planting and another at 13 years, encompassing the typical productivity range in plantations in this region. Such data allowed developing simple but representative linear, polynomial and power equations to estimate volume explaining 93%–98% of the observed variability. Such equations can be easily implemented in any cellphone with a calculator, allowing forest owners to accurately estimate their timber existences by using only a regular measuring tape to measure tree diameter. However, models for height were less successful, explaining only 75%–76% of observed variance. Our approach to generate simplified volume equations has shown to be viable for poplar, but it could be applied to any species for which several volume equations are available.

Vertical patterns in specific volume increment along stems of dominant jack pine (Pinus banksiana) and black spruce (Picea mariana) after thinning

2012 ◽  
Vol 42 (4) ◽  
pp. 733-748 ◽  
Author(s):  
Venceslas Goudiaby ◽  
Suzanne Brais ◽  
Frank Berninger ◽  
Robert Schneider
Keyword(s):  
Picea Mariana ◽  
Specific Volume ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Mass Density ◽  
Volume Growth ◽  
Jack Pine ◽  
Stem Volume ◽  
Volume Increment ◽  
Foliage Density

Jack pine ( Pinus banksiana Lamb.) and black spruce ( Picea mariana (Mill.) B.S.P.) total stem volume increment and vertical growth distribution after thinning were quantified and related to foliage biomass, foliage density, and growth efficiency (GE) (stem to foliage biomass ratio). Significant positive stem volume increments were observed following thinning for jack pine (3 years after) and black spruce (4 years after). Both species reacted differently in terms of the distribution in specific volume increments (SVI) (annual stem volume increment to cambial surface ratio): (i) for jack pine, an increase in SVI was first observed at the base of the tree, with the increase moving upwards, showing that the taper was likely to increase following thinning and (ii) for black spruce, the vertical distribution of SVI was constant, leading to no modifications in stem taper. For jack pine, total stem volume growth was related to an increase in GE and a greater foliage biomass at midcrown, with foliage density staying constant. For black spruce, however, no changes in GE, foliage biomass, and foliage mass density were observed.

Effects of Crown Thinning on Baldcypress Height, Diameter, and Volume Growth

1988 ◽  
Vol 12 (4) ◽  
pp. 252-256 ◽  
Author(s):  
Stephen G. Dicke ◽  
John R. Toliver
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Taxodium Distichum ◽  
Volume Increment ◽  
Crown Thinning ◽  
Epicormic Branching

Abstract Crown thinning a 63-year-old stand of baldcypress (Taxodium distichum [L.] Rich.) averaging 220 ft²/ac of basal area to 180, 140, and 100 ft²/ac resulted in 5-year diameter growths of 0.44, 0.51, and 0.77 in., respectively. The unthinned control was significantly less at 0.31 in. Six-year height growth averaged 3.1 ft and was not influenced by treatment. Thinning to 140 and 100 ft²/ac stimulated epicormic branching on many trees, which may lower log quality. All crown thinning treatments appeared to increase sawtimber volume increment and sawtimber volume/ac over the control 5 years after thinning. South. J. Appl. For. 12(4):252-256.

Competition among seedlings of perennial grasses, subterranean clover, white clover, and annual ryegrass in replacement series mixtures

2000 ◽  
Vol 51 (3) ◽  
pp. 377 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
White Clover ◽  
Plant Competition ◽  
Perennial Grass ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Maximum Likelihood Estimates ◽  
Annual Ryegrass ◽  
Replacement Series ◽  
Successful Establishment

Seedlings of 3 perennial grasses, Danthonia linkii Kunthcv. Bunderra, D. richardsonii Cashmore cv. Taranna(wallaby grasses), and Phalaris aquatica L. cv. Sirosa,were each grown in replacement series mixtures with seedlings ofTrifolium repens L. (white clover),Trifolium subterraneum L. var. brachycalycinum (Katzn.et Morley) Zorahy & Heller cv. Clare (subterraneanclover), and Lolium rigidum L. (annual ryegrass). Plantswere sown 5 cm apart in boxes (45 by 29 by 20 cm) at a density of 307plants/m2. Maximum likelihood estimates were usedto derive parameters of a non-linear competition model using the dry matterweights of perennial grasses and competitors at 3 harvests, approximately 168,216, and 271 days after sowing. Intra-plant competition was examined inmonocultures of each species, grown at plant spacings of 2, 5, and 8 cm apartwith plants harvested at the above times.Competition occurred in all perennial grass–competitor mixtures, exceptin those of each perennial grass with white clover and thephalaris–subterranean clover mixture (Harvest 1) and those withD. richardsonii and phalaris grown with white clover(Harvest 2). For D. richardsonii (Harvests 1 and 2) andD. linkii (Harvest 1 only) grown with white clover andthe phalaris–subterranean clover (Harvest 1), the two species in themixture were not competing. In the phalaris–white clover mixture, eachspecies was equally competitive (Harvests 1 and 2). These differences incompetition and aggressiveness reflected differences in individual plantweights in monocultures where there was an effect (P < 0.05) of species ondry matter weight per box, but no significant effect of plant spacing.These data indicated that for successful establishment,D. richardsonii and D. linkiishould not be sown in swards with either subterranean clover or white clover,or where populations of annual ryegrass seedlings are likely to be high.Phalaris was more compatible with both white clover and subterranean clover,but aggressively competed with by annual ryegrass.

Satellite derived maps of pasture growth status: association of classification with botanical composition

1997 ◽  
Vol 37 (5) ◽  
pp. 547 ◽  
Author(s):  
P. J. Vickery ◽  
M. J. Hill ◽  
G. E. Donald
Keyword(s):  
Near Infrared ◽  
Perennial Grass ◽  
Vegetation Indices ◽  
Fast Growth ◽  
Perennial Grasses ◽  
Bayesian Probability ◽  
Cumulative Probability ◽  
Botanical Composition ◽  
South Wales ◽  
Native Pastures

Summary. Spectral data from the green, red and near-infrared bands of Landsat MSS and Landsat TM satellite imagery acquired in mid-spring were classified into 3 and 6 pasture growth classes respectively. The classifications were compared with a site database of botanical composition for the Northern Tablelands of New South Wales to examine the association between spectral growth class and pasture composition. Pastures ranged in composition from unimproved native perennial grasses through semi-improved mixtures of native and naturalised grasses and legumes to highly improved temperate perennial grasses and legumes. For 3 years of MSS data, the fast growth class had a mean botanical composition of about 80% improved perennial grass and 0% native; medium growth class averaged 46% improved perennial grass and 14% native; while the slow growth class had about 60% native and 1% improved perennial grass when averaged over 3 years of MSS data. For the 6 class TM data from a single year, a predictive logistic regression of cumulative probability was developed for percentage of ‘very fast’ growth pixels and ordered 10 percentile categories of improved perennial grass or native grass. Differences in patch characteristics between classes with MSS disappeared with TM reclassified to the same 3 class level. Most probable pasture type was inferred from 3 class MSS and TM data using Bayesian probability analysis. The resulting maps were similar in general appearance but detail was better with the TM data. The pasture growth classification identified highly improved perennial grass pastures and native pastures but sensitivity to intermediate pasture types was poor. Future improvement will come from direct measurement of biophysical characteristics using vegetation indices or inversion of reflectance models.

Bt-Cry3Aa transgene expression reduces insect damage and improves growth in field-grown hybrid poplar

2014 ◽  
Vol 44 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Amy L. Klocko ◽  
Richard Meilan ◽  
Rosalind R. James ◽  
Venkatesh Viswanath ◽  
Cathleen Ma ◽  
...  
Keyword(s):  
Large Scale ◽  
Populus Deltoides ◽  
Integrated Management ◽  
Populus Trichocarpa ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Field Trials ◽  
Leaf Beetle ◽  
Insect Damage ◽  
Beetle Damage

The stability and value of transgenic pest resistance for promoting tree growth are poorly understood. These data are essential for determining if such trees could be beneficial to commercial growers in the face of substantial regulatory and marketing costs. We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa transgene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa × Populus deltoides, clones 24-305, 50-197, and 198-434; and P. deltoides × Populus nigra, clone OP-367) resulted in transgenic trees with greatly reduced insect damage. A large-scale study of 402 trees from nine insertion events in clone OP-367, conducted over two growing seasons, demonstrated reduced tree damage and significantly increased volume growth (mean 14%). Quantification of Cry3Aa protein indicated high levels of expression, which continued after 14 years of annual or biannual coppice in a clone bank. With integrated management, the cry3Aa gene appears to be a highly effective tool for protecting against leaf beetle damage and improving yields from poplar plantations.

Sources of valuable traits for perennial grass breeding

2021 ◽  
pp. 78-89
Author(s):  
LZ Baistruk-Hlodan ◽  
MM Кhomiak ◽  
HZ Zhapaleu
Keyword(s):  
Festuca Arundinacea ◽  
Trifolium Pratense ◽  
Perennial Grass ◽  
High Energy ◽  
Phleum Pratense ◽  
Perennial Grasses ◽  
Starting Material ◽  
Forage Production ◽  
Daily Growth ◽  
Galega Orientalis

Aim. The purpose was to identify collection accessions – sources of valuable traits to use as starting material for creating varieties of perennial grasses in Western Ukraine. Results and Discussion. Perennial grasses play an essential role in improving the efficiency of forage production. They produce a fodder mass that contains major macro- and micronutrients, minerals, vitamins, amino acids, and other nutrients in available forms, with a high energy protein saturation. Practice shows that due to the introduction of varietal crops into production in combination with optimal technologies of their cultivation, which allows revealing the potential of each variety, it is possible to additionally obtain 20-30% higher yields of fodder mass annually and harvest 2 to 3-fold seed yields. In 2016-2020, a search was carried out and 570 new accessions of perennial grasses were recruited, of which 201 were legumes and 369 were graminaceous grasses. The collection contains 1,319 accessions, of which 232 are Trifolium pratense L., 115 are Trifolium repens L., 49 are Trifolium hybridum L., 107 are Lotus corniculatus L., 80 belong to other legume species (Medicago, Galega orientalis L. Galega orientalis L. and Trifolium species), 131 are Phleum pratense L., 187 are Dactylis glomerata L., 146 are Lolium perenne L., 53 are Arrhenatherum elatius (L.) J. et C.Presl., 67 are Festuca rubra L., 28 are Festuca trachyphylla L., 32 are Bromopsis inermis (Leyss.) Holub, 92 belong to other species of other types of graminaceous grasses (Festuca pratensis Huds., Festuca arundinacea Schreb., Agrostis alba L. etc.). Accessions that enter the Department are registered and sown for propagation in the field. After examination, valuable accessions are transferred to the National Depository and registered in the National Catalogue; the rest of the obtained seeds are used in working collections. Conclusions. The best collection accessions were identified by a set of economically valuable traits: sources of daily growth of shoots (30), winter hardiness (28), plant height (22), yield of green mass upon haymaking (28) and pasture (19) use, forage productivity (15), seed productivity (25), foliage (21), and disease resistance (23). They can be recommended as starting material to create varieties of perennial grasses with high yields of forage mass and seeds for various applications.

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