Effect of initial planting density and tree features on growth, wood density, and anatomical properties from a Hevea brasiliensis trial plantation

The effect of initial planting density (500, 1,000, 1,500, and 2,000 trees per ha) on tree growth, wood density, and wood anatomical properties was studied in a 9-year-old Heave brasiliensis plantation in Malaysia. Results showed that effects of initial planting density on tree radial growth, wood density, fiber length, fiber wall thickness, and ray density were more visible in trees planted at 500 trees per ha compared with the other planting densities. Bole length was significantly increased with higher planting densities. However, vessel density showed an infinite pattern with increasing planting density. For vessel and ray areas, no significant effect of initial planting density was detected. A negative relationship was observed between wood density, fiber length, and fiber wall thickness with planting density, bole length, and height-to-diameter ratio. The ray density was significantly and positively correlated with stand/tree features with the exception of a negative correlation with radial growth increment. The regression models with various degrees of goodness of fit indicated that wood density followed by fiber wall thickness was successfully quantified due to selected stand/tree features. According to the results of this study, it is recommended that a low planting density of 500 trees per ha is ideal for rubberwood plantation development

The effects of initial planting density on above- and below-ground biomass in a 25-year-old Fagus orientalis Lipsky plantation in Hopa, Turkey

The aim of this study was to determine the influence of initial planting density on above- and below- ground biomass in 25 years old oriental beech stands located in Hopa, Artvin, Turkey. The initial spacings used in this study were 0.7 x 2.0 m ( high planting density) and 2.0 x 2.0 m (low planting density). To analyse the planting density response of trees of different sizes (diameter), the sample trees within each stand density class were classified into four dbh classes (dbh1, dbh2, dbh3, dbh4) according to their diameter at the time of measurement. In each planting density stems, basal area, volume, aboveground biomass and C showed significant differences among diameter classes. In high density stand dbh2 (5.0 - 9.9 cm) had the highest basal area, volume, biomass and C. While, these measured data were the highest in db3 (10.0 - 14.9 cm) in low density stand. Although volume and aboveground biomass showed significant differences in diameter classes in each planting density, they were not affected by planting density. In high planting density dbh2 trees with a diameter of 0 - 4.9 cm had the highest volume (52 m3 ha-1), above-ground biomass (7.7 ton ha-1) and C (3.4 ton ha-1), whereas in low planting density dbh3 with a diameter of 5.0 - 9.9 cm had the highest volume (46 m3 ha-1), biomass (6.22 ton ha-1) and C (2.80 ton ha-1). However, stand basal area, belowground root biomass and C was higher in high planting density stand than in low planting density stand

High density planting - an option for higher productivity of Hevea brasiliensis in north eastern region of India

The effect of planting density in rubber (Hevea brasiliensis) was studied in an experiment conducted with three densities viz., 420, 620, 824 trees ha-1. It was observed that lower density had higher percentage of trees ready for tapping during initial years, due to better growth. However, higher density achieved required girth in subsequent years. In spite of decrease in plant number over the years, the highest density had always lower girth even after 24 years of planting. Higher density also has higher percentage of too small trees, not suitable for harvesting latex. The higher plant densities resulted taller plants, increased crotch height and decreased the number of branches and thereby plant density affected yield per tree and yield per unit area. Though the yield per hectare increased with increased plant density during initial years, however declined later period. High yield per tree per tap was observed in the lowest density with lower yield per unit area. Yield increased in all densities with application of stimulant. Percentage of yield increase due to application of stimulant was higher (40%) in medium density (620 trees ha-1) compared to other plant densities. Percentage of wind damage was lower in high density planting during initial years. Total timber volume per hectare was high in higher planting density and lower per tree volume of log compared to lower density. Maintaining a density of 620 trees per hectare appears to be most suitable for north eastern region of India

Effects of initial planting density on branch development in 4-year-old plantation grown Eucalyptus pilularis and Eucalyptus cloeziana trees

The effect of planting density on branch development was examined in 4-year-old Eucalyptus pilularis Sm. and Eucalyptus cloeziana F. Muell. plantations located near the coast of north-eastern NSW. Branch diameter, angle and status (live or dead) were measured along the entire stem of trees established at 1250, 1667 and 3333 stems per hectare (sph). Measurements of tree height and stem diameter at breast height over bark (DBH) were also recorded. Results showed that with an increase in initial planting density from 1250 to 1667 sph, branch size decreased, branch mortality on the lower stem increased, branch angle became more acute and DBH decreased in trees of both E. pilularis and E. cloeziana. A further increase in initial planting density from 1667 to 3333 sph did not significantly reduce branch size or branch angle but did result in increased branch mortality and decreased DBH in both species. These results suggest that increasing initial planting density from 1250 to 1667 sph will improve early branch control. However, there is no advantage in establishing trees at 3333 sph rather than 1667 sph to reduce branch size or increase branch mortality in either species. Clearwood production on the lower stem in all stocking treatments of both species was negligible at age 4

Planting density effect on some properties of Schizolobium parahyba wood

This study aims to understand the effect of the initial planting density on the anatomical variability and basic wood density of Schizolobium parahyba var. amazonicum in a planted forest in Amazonia. The effect of the initial planting density on the radial variation from pith to bark of anatomy and basic density was evaluated. There were two planting densities, planting density-I (624 trees ha-1) and planting density-II (312 trees ha-1). Planting density significantly affected only the ray height, fiber length and wall thickness. Radial position was not significant to the height of the rays and the fiber lumen diameter. The interaction planting density × radial position was only significant for the length of the vessel elements, ray frequency and fiber length. The results indicate that the initial planting density influences the radial behavior of certain anatomical characteristics. To obtain gain in terms of total wood per cultivated area, without harm to the density of the produced wood, planting density-I would be most useful, while planting density-II would be suitable for the production of more homogeneous wood, which tends to form adult wood in advance and with some anatomical characteristics appropriate for the plywood industry

Pokusi s početnom gustoćom sadnje poljskog jasena u Turskoj: desetogodišnji rezultati

Narrow-leaved ash (Fraxinus angustifolia subsp. oxycarpa Vahl.) is a source of valuable wood in Europe and plantations produce high yields in Turkey. Initial planting density plays an important role in plantation silviculture and affects the growth and quality of trees as well as establishment costs. This study aimed to determine the ten-year effects of initial planting density on tree growth and quality of narrow-leaved ash. In 2004, three replications of four initial planting densities (1111, 1667, 2500 and 3333 stem ha–1) were established in a randomized block design in Adapazarı, Turkey. After ten growing seasons, no mortality was seen in all of four planting densities. The initial planting density had no effect on mean stem diameter; however, with the initial planting density increase from 1111 to 3333 stem ha–1, mean tree height was significantly increased and live crown ratio decreased. The H/D ratios at planting densities of 2500 and 3333 stem ha–1 were 21% higher than at lower planting densities. Aboveground dry biomass increased with increasing initial planting density at the stand level, although individual tree sizes were similar. In general, tree form and branch characteristics were improved when initial planting density was increased. Results suggest that on lowland sites where intensive weed competition occurs, higher initial planting density at 2500‒3333 stems ha–1 is recommended for narrow-leaved ash plantations.Poljski jasen (Fraxinus angustifolia Vahl.) je izvor vrijednog drva u Europi, a plantaže poljskog jasena u Turskoj daju visoke prinose. Gotovo sve prirodne nizinske šume u kojima dominira poljski jasen pretvorene su u posljednjih 60 godina u čiste plantaže poljskog jasena u regiji Adaparazi, u kojoj se nalaze najveće šume ove vrste drveća. Potražnja za pilanskim trupcima velikih promjera je u stalnom porastu pa je stoga važno osigurati optimalnu gustoću sadnje. İz razloga što je početna gustoća sadnje najvažniji čimbenik koji određuje gustoću, rast i kvalitetu stabala, ophodnju i troškove gospodarenja na plantažama. Godine 2004. postavljen je dugotrajni pokus gustoće sadnje s četiri različite početne gustoće sadnje, koja je uključivala 1111, 1667, 2500 i 3333 stabala ha-1 u Akyazi-Adapazan, regiji Turske u kojoj su plantaže poljskog jasena česte. Sadnice poljskog jasena s golim korijenom starosti 1+0 (visine od 65 do 75 cm) proizvedene su u rasadniku Hendek i posađene u prosincu 2004. godine. Cilj ovog rada je utvrditi desetogodišnji utjecaj početne gustoće sadnje na rast i kvalitetu stabala (oblik stabla i karakteristike grana) poljskog jasena. Godine 2015., deset godina nakon sadnje, izmjerene su prsne visine, visine stabla, visine do najniže mrtve grane i najniže žive grane te maksimalni promjer živih i mrtvih grana, a nakon toga su izračunati omjer između visine i prsnog promjera, (H/D), omjer živih grana, volumen debla, kvocijenti oblika i nadzemne suhe biomase. Nakon deset godina rasta, nije primijećen mortalitet ni u jednoj od četiriju početnih gustoća sadnje. Početna gustoća sadnje nije imala nikakav učinak na srednji promjer debla; međutim, s porastom početne gustoće sadnje od 1111 na 3333 debla ha-1, srednji visina stabla je značajno porastao a omjer živih krošnji se smanjio. Omjeri H/D pri početnim gustoćama sadnje od 2500 i 3333 stabala ha-1 bili su 21% viši nego oni pri manjim gustoćama sadnje. Na nivou sastojine, nadzemna suha biomasa porasla je s porastom početne gustoće sadnje, premda su veličine pojedinih stabala bile slične. Općenito, oblik stabala i karakteristike grana su se poboljšale s porastom početne gustoće sadnje. Uz to, pošto je sklop krošanja kod početne gustoće sadnje od 2500 i 3333 stabala po hektaru bio potpuno sklopljen, rast korova bio je slab i rijedak. Međutim, gusti rast visokog korova pri početnim gustoćama sadnje od 2500 i 3333 stabla po hektaru mogu izrazito otežati njegu sastojine. Dosadašnji rezultati sugeriraju da početna gustoća sadnje bude od 2500 i 3333 stabla po hektaru na plantažama poljskog jasena, jer su prsni promjer, visina, volumen sastojine, visina do najniže mrtve grane i omjer H/D slični pri ove dvije sadnje. Međutim, troškovi gustoće sadnje od 3333 stabala po hektaru (sadnice, sadnja, njega nakon sadnje) bit će viši; prema tome, uzgajivači bi se umjesto veće početne gustoće sadnje mogli odlučiti za manju s 2500 stabala po hektaru

Effect of intensive planting density on tree growth, wood density and fiber properties of maple (Acer Velutinum Boiss.)

Planting density is a major factor in determining tree growth and wood quality. Although the effect of low planting density on the variation of tree and wood characteristics has been already reported, the effect of intensive initial densities in plantations has not been fully assessed yet. In this study, the effect of intensive planting densities on tree growth, wood density and fiber cell properties was investigated in the context of the development of densely-stocked maple plantations for wood production. The study was carried out in a 12-year-old Acer velutinum trial plantation in northern Iran, with initial densities of 10000, 4444, and 2500 trees ha-1 planted. The variation of diameter at breast height, annual ring width, stem taper, wood density, and fiber cell properties were examined. As expected, low planting densities showed trees with larger diameter at breast height and annual ring width. The largest trees at higher densities were smaller than those in lower planting densities. However, initial planting density had no significant effect on stem taper, wood density and fiber cell properties. In addition, no significant relationships between tree growth features and wood properties were detected, indicating similar wood properties at all planting densities. Therefore, stand/tree growth attributes under intensive planting densities could not be considered as reliable predictors of the wood properties

Biomass production and nutritional composition of Moringa oleifera under different planting spacings in a semi-arid condition of the northern South Africa

Moringa oleifera is an important plant with nutrients concentrated in the leaves. The leaves have high nutritional potential, which can contribute significantly towards human and animal nutrition. Therefore, the tree can feed communities when other foods are typically scarce. This study was conducted to evaluate the effect of planting density on biomass and nutritional composition of Moringa oleifera planted under the semi-arid conditions of the Limpopo Province. The study was conducted at Eiland (NBef Organic Farm) over two consecutive years, 2014–15 and 2015–16. The  initial and post-planting physical and chemical properties of the soil at the site were carried out at depths of 0 to 30 and 30 to 60 cm. The experiment was established as a randomized complete block design and replicated eight times. The treatments included planting densities of 5 000, 2 500, 1 667 and 1 250 plants ha-1. Data collection included total dry matter yield, leaf yield (kg ha-1) and leaf nutritional composition. Results from the soil  analysis revealed slight acidity and very low nitrogen content (0.08%) at all sampling depths before moringa establishment. In addition, excessive magnesium, manganese and copper contents in the soil were recorded. Soil properties such as phosphorus, potassium, zinc, copper, organic carbon and nitrogen were reduced after the first harvest. During the second harvest, similar soil nutrient reductions followed the same trend as  compared to the first harvest except for phosphorus, which showed an increase as compared to initial soil sampling at the second harvest. During harvests 1 and 2, the increase in planting density resulted in increased biomass production. Planting densities also did not affect moringa leaf nutrient composition. The study showed that a population of 5000 plants ha-1 produced the highest biomass yield of more than 1.5 ton ha-1. This  study also revealed that moringa contains a high level of leaf nutrients even under marginal production conditions, irrespective of the planting density. Key words: Biomass production, leaf nutritional composition, moringa, planting populatio

High Density Planting in Mango cv. Alphonso

A trial was conducted to optimize spacing for high density planting in mango cv. Alphonso to obtain higher yield/ unit area at the Agriculture Research Station, Mulde, during 2006-07 to 2008-09 with four close spacings and one normal spacing as control. Highest yield (6.4 MT/ha) was recorded with a spacing of 5 m x 5 m without reduction in fruit size in 10 year old plants compared to the mean yield of 1.12 MT/ha in 10m x 10m normal spacing. High density plantation helped to get significantly higher yield per unit area compared to the normal spacing, without affecting size and quality of mango fruits. The highest cost:benefit ratio (2.33) was recorded in high density plantation of 5m x 5m, with maximum net returns of Rs.1,12,000/- per hectare. The present findings show promise for more yield and returns per unit area during the initial years of mango plantation by adopting 5m x 5m high density planting

Impact of forest management regimes on ligneous regeneration in the Sudanian savanna of Burkina Faso

Annual early fire, selective tree cutting and grazing exclusion are currently used to manage the State forests of the Sudanian savanna of Burkina Faso, West Africa. Such prescriptions, however, are not based on experimental evidence. The long-term effects of such management on seedlings and saplings and the germination of selected tree species are discussed. Seedling quality attributes are also assessed. Studies over a 10-year period examined the effects of the three management regimes on species richness and population density. Burkea africana Kook, f., Detarium microcarpum Guill. et Perr., Entada africana Guill. et Perr., and Pterocarpus erinaceus Poir. seed germination was tested for different temperatures, light conditions, dry heat treatments and scarification methods. The quality of Acacia macrostachya Reichenb.ex DC. and P. erinaceus planting stock was evaluated in relation to nursery production period; field performance was assessed with and without watering. Fire, grazing, and selective tree cutting acted independently on sapling and seedling population dynamics. Early fire reduced sapling recruitment; moderate grazing had no significant effect. Although the overall seedling population density was not affected by any of the treatments, fire and grazing had strong effects on single-stemmed seedling density. Ordination using Principal Component Analysis of the seedling population data revealed species-specific responses to treatments, in particular an increase of lianas compared to other species. D. microcarpum and E. africana seeds did not exhibit dormancy. Exposing B. africana seeds to 95-97% sulphuric acid for 15–20 minutes broke their physical dormancy. All seeds tested were neutrally photoblastic, with an optimal germination temperature of 25–35 oC. E. africana, however, germinated over a wider temperature range. P. erinaceus seeds did not tolerate heat shock; while D. microcarpum and E. africana seeds responded positively at low intensity. Eighteen months after outplanting, survival and growth of Acacia macrostachya and Pterocarpus erinaceus seedlings were not affected by their initial size. Drought and non-drought factors affected seedling survival. Performance of P. erinaceus seedlings could be predicted from initial root collar diameter; more data will be required to build a reliable model. This thesis recommends the use of annual early fire as a forest management tool to be continued if timing, weather conditions and other factors affecting fire intensity are given due consideration. Moderate level of grazing does not affect seedling and sapling recruitment. The current prohibition on grazing State forests may need revision to allow multiple-use management. The low seedling density of socio-economically valuable species indicates that natural regeneration could be supplemented by planting high quality seedlings