Grandis Plantations Research Articles

Vegetation composition and structure of Tectona grandis (teak, Family Verbanaceae) plantations and dry deciduous forests in central India

Vegetation structure and composition of abandoned Tectona grandis (teak) plantations was compared with the neighboring dry deciduous secondary forests in Satpura Conservation Area located in central India. Species diversity and stem density were compared between plantations and secondary dry deciduous forests separately for adults and seedlings of trees, shrubs and lianas (collectively termed woody species). No significant difference was found between the two vegetation types in the seedling and adult species diversity. The adult stem density was significantly higher in plantations compared to the secondary forests, but the opposite was found to be true for basal area perindividual. Species abundance in plantations deviated from log-normal distribution while the secondary forests showed log-normal species abundance distribution. The size-class distribution of adults in plantations had greater positive skewness than the secondary forests due to high relative abundance of species in smaller size-classes. Overall results show that plantations have similar species richness as secondary forests, but have disproportionate abundance of sprouting and asexually reproducing species.

Soil-site productivity of Gmelina arborea, Eucalyptus urophylla and Eucalyptus grandis forest plantations in western Venezuela

Commercial forest plantations have become a competitive alternative to harvesting natural forests in many parts of the world, especially in the tropics and sub-tropics. More research about tree farm site selection is needed, and one of the major considerations of site selection is the site’s productivity. The purpose of this research was to explore the soil factors that are indicators of site productivity. A study was conducted in a dry tropical region of western Venezuela on Gmelina arborea, Eucalyptus urophylla, and Eucalyptus grandis plantations to identify the soil properties that provide optimum growing conditions for these species. Results of a multiple regression analysis indicated that soil texture was a significant predictor of tree growth for all three species. All species grew best in soils with clay loam textures. Excessive soil moisture was inversely correlated with tree growth in Eucalyptus grandis. As commercial forestry companies in western Venezuela expand their land holdings through new acquisitions, this knowledge will improve their ability to select land parcels that are economically optimal for plantation purposes.

Species richness and fluctuation of defoliator Lepidoptera populations in Brazilian plantations of Eucalyptus grandis as affected by plant age and weather factors

The effect of plant age and weather factors on species richness and fluctuation of defoliator Lepidoptera populations was investigated in a Eucalyptus grandis plantation subjected to a five-year survey (June 1993–July 1998) in Santa Bárbara County, State of Minas Gerais, Brazil. Adult Lepidoptera were collected every 15 days with five light traps, and the number of individuals per morphospecies in each site was recorded. Lowest numbers of individuals were obtained in July (14.4 ± 4.7 insects/trap) and highest numbers were obtained by late December (86.8 ± 41.1 insects/trap). During the five-year period, 653 species of Lepidoptera were collected and the Geometridae Stenalcidia grosica, Glena unipennaria, and Oxydia vesulia were the most abundant species. The mean seasonal fluctuation of the first two species were positively correlated with the total Lepidoptera fluctuation ( p < 0.01; r = 0.6; n = 98), unlike the third species (i.e. O. vesulia) which was poorly correlated with the total fluctuation ( p = 0.05; r = 0.2; n = 98). Multiple regression models were developed to assess the relative importance of plant age and weather factors (temperature, relative humidity, and rainfall) affecting species richness and fluctuation of Lepidoptera populations. Plant age and average temperature were the main weather factors affecting species richness and abundance of total individuals and individuals of the species S. grosica. Older plants (six- to seven-years old) and lower temperatures (≈18°C) seem to favor species richness and higher populations of Lepidoptera, especially S. grosica. In contrast, plant age and rainfall were the main factors affecting the fluctuation of G. unipennaria populations which presented higher incidence in older plants (six- to seven-years old) and higher rainfall (≈400 mm). We were unable to develop robust models for fluctuation of O. vesulia populations ( r 2 < 0.15). The obtained results suggest that high populations of the main defoliator Lepidoptera species present in the area are more likely to occur in plants older than five years and especially during the rainy season (October–March).

Change in organic carbon in forest plantation soils in eastern Australia

Effects on soil organic carbon of establishing forest plantations were assessed using paired plot and chronosequence techniques. Paired plots were located in radiata pine ( Pinus radiata D. Don) plantation sites located over a wide range of soil fertilities. In each case, one plot in each pair was located in relatively mature plantation and the other in adjacent existing native forest. Soil organic carbon under plantation was lower than under adjacent (original) native forest and a model was developed to relate the declines in carbon to the soil fertility range. Two chronosequences were studied, one located in a series of relatively fertile P. radiata unthinned plantations, 0–24 years of age, and the other in 0–35 years of age Eucalyptus grandis plantations, also unthinned. In these studies, there was an apparent rapid decline in organic carbon in surface soil (0–10 cm) for ca. 12 years after plantation establishment. Soil organic carbon then stabilized with some indication of increases ca. 20 years after plantation establishment. There was a larger loss of carbon from the deeper horizon (to 50 cm) within two years after plantation establishment and carbon continued to decline over the length of the two chronosequences. The net effect was a loss of soil organic carbon in the plantations over the duration of the study periods. Analysis was also undertaken on carbon input processes and the varying impacts of management. Soil disturbances involved in establishment of plantations result in decomposition of soil carbon and losses of carbon occurred at different rates in different parts of the soil profile. The losses will be offset by accumulation of carbon in vegetation. However, the period where the net effect is zero varies with different plantations but is of the order of decades. That is, net accumulation in the total system does not occur for ≈10–20 years after plantation establishment. These results have significant implications for fast growing, short rotation plantations (<15 years of age) for pulpwood or biofuels, and soil carbon decline can be expected to continue over subsequent rotations. Plantation management systems can be modified to reduce carbon losses and modify the period up to the time when net accumulation commences.

Nighttime water use in an irrigated Eucalyptus grandis plantation.

Sap flow measurements showed that a well-watered four-year-old plantation of Eucalyptus grandis (Hill ex Maiden) at Wagga Wagga, New South Wales, Australia, used 0.8 mm of water between 2100 and 0500 h on the midwinter night of July 30. Sap flow ceased for 2 to 3 h after sunset before recommencing at high rates that reached a maximum of 0.3 mm per h between 0200 and 0300 h. This pattern is inconsistent with the replenishment of tissue water reserves depleted during the day. Moreover, maximum leaf conductance at night was about 20 times maximum cuticular conductance values reported in the literature, which strongly suggests that stomata were partly open and that there was substantial water loss by way of the foliage. In an 8-month period from late winter to mid-autumn, comparable rates of nighttime water use were observed on only one other occasion. However, water use at rates of 0.1 mm per h or more occurred on 24 other nights. Almost 70% of the variation in nighttime sap velocity was explained by nighttime mean vapor pressure deficit and nighttime mean wind speed. Total recorded nighttime water use of the plantation was 48 mm, or 5% of total transpiration during the 8-month study. In view of the insensitivity of heat pulse measurements at low sap flows, this value may be an underestimate of actual nighttime transpiration.

Stomatal control of transpiration in the canopy of a clonal Eucalyptus grandis plantation

Predawn leaf water potential, stomatal conductance and microclimatic variables were measured on 13 sampling days from November 1995 through August 1996 to determine how environmental and physiological factors affect water use at the canopy scale in a plantation of mature clonal Eucalyptus grandis Hill ex-Maiden hybrids in the State of Espirito Santo, Brazil. The simple ”big leaf” Penman-Monteith model was used to estimate canopy transpiration. During the study period the predawn leaf water potential varied from –0.4 to –1.3 MPa, with the minimum values observed in the winter months (June and August 1996), while the average estimated values for canopy conductance and canopy transpiration fell from 17.3 to 5.8 mm s–1 and from 0.54 to 0.18 mm h–1, respectively. On the basis of all measurements, the average value of the decoupling coefficient was 0.25. During continuous soil water shortage a proportional reduction was observed in predawn leaf water potential and in daily maximum values of stomatal conductance, canopy transpiration and decoupling coefficient. The results showed that water vapour exchange in this canopy is strongly dominated by the regional vapour pressure deficit and that canopy transpiration is controlled mainly by stomatal conductance. On a seasonal basis, stomatal conductance and canopy transpiration were mainly related to predawn leaf water potential and, thus, to soil moisture and rainfall. Good results were obtained with a multiplicative empirical model that uses values of photosynthetically active radiation, vapour pressure deficit and predawn leaf water potential to estimate stomatal conductance.

The response in water yield to the thinning of Pinus radiata, Pinus patula and Eucalyptus grandis plantations

The paired catchment method was used to test for the effects of thinning on the water yield in three afforested catchments in South Africa, namely, Biesievlei, Jonkershoek, 98% afforested with Pinus radiata (three thinnings); Westfalia catchment D, 100% afforested with Eucalyptus grandis (two thinnings); and Cathedral Peak CII that was 74% afforested with Pinus patula (one thinning). During and after two separate thinnings, each of which removed roughly one third of the stems in a maturing P. radiata plantation in the Biesievlei catchment, annual streamflow increased by between 10 and 71% (19–99 mm). These increases persisted for three and two years after the thinning, respectively. A final thinning in the same catchment removed only 22% of stems at an age of 28 yr. The following years (1977 and 1978) were wetter than average, and reductions in annual streamflow of 26 and 55% were recorded in these two years. At Westfalia catchment D and Cathedral Peak CII, the hydrological trends were entirely dominated by the rapidly declining streamflow caused by the developing E. grandis and P. patula plantations respectively. Any savings in water use that may have resulted from the thinning of these plantations were insufficient to affect the downward trend in annual streamflow. Thinnings may have had a minor effect of delaying or reducing the desiccation of these catchments but such effects could not be assessed due to natural variability and the limited resolution of the paired catchment method. The trends in total water yield from the catchments were generally mirrored in the dry season streamflow, and there were no strong indications that thinning effects are linked to a particular season.

Kraft Pulping Properties ofAcacia mearnsiiandEucalyptus grandisGrown in Zimbabwe

SYNOPSIS Pulpwood samples from 8-year old Acacia mearnsii and Eucalyptus grandis plantations grown in Zimbabwe were evaluated for kraft pulping, bleaching and papermaking properties. The possibility of co-pulping the two species was also investigated. A. mearnsii had higher chip basic density than E. grandis, and required more active alkali to produce less pulp. At about the same Kappa number, the A. mearnsii pulp had lower strength properties but higher opacity. Pulps of both species could be bleached to an acceptable brightness. The results demonstrated that the conventional prejudice against the use of A. mearnsii as pulpwood in Zimbabwe may be undeserved. The species has superior pulpwood productivity and can be successfully co-pulped with E. grandis, the preferred hardwood pulpwood species in Zimbabwe.

Changes in soil chemistry in efluent-irrigated Pinus radiata and Eucalyptus grandis plantations

Two tree species (Pinus radiata and Eucalyptus grandis) were planted in 1991 and irrigated weekly with either secondary-treated effluent or bore-water, in an effluent-irrigated plantation at Wagga Wagga, NSW. Changes in soil salinity, sodicity, alkalinity, and the accumulation of potentially toxic elements after 2 and 4 irrigation seasons were studied. The average sodium adsorption ratio (SAR) and electrical conductivity (EC) of effluent were 4·8 and 0·79 dS/m, while in bore water they were 3·3 and 0·70 dS/m, respectively. Effluent was applied at 3 rates: the water-use rate of the plantation less rainfall (medium treatment, M), a nominal rate 0·5 times M (low treatment, L), and a nominal rate 1·7 times M (high treatment, H). The bore-water treatment (W) was irrigated at its water-use rate less rainfall. Salinity of saturation paste extracts in the surface 0·05 m increased from a pre-treatment value of 1 dS/m to 2–3 dS/m after 4 years of effluent irrigation. The increase in soil salinity was consistent with the salt loading for the different irrigation treatments. Similarly, exchangeable sodium percentage (ESP) increased in all treatments. The ESP was generally &lt;2% at the start of the experiment and increased to a maximum of 25% in the 0·3–0·4 m soil layer of treatment L. Values had changed throughout the 4 irrigation seasons and the soil profile does not appear to have reached a steady-state condition. Soil pH increased in all treatments. The largest increase (≈0·7) occurred in treatment H, while treatment W had the smallest increase (≈0·4). The increase in soil pH caused a decrease in exchangeable Al and Mn in the upper 0·4 m of the soil profile in all treatments. Effective cation exchange capacity (ECEC), approximated by the sum of the extractable cations, increased significantly in the upper 0·3 m of the soil profile after 2 and 4 irrigation seasons, but there was no significant change in ECEC below 0·3 m.

Stand density effects on Eucalyptus grandis growth in Entre Ríos

The Mesopotamia region comprises the largest Eucalyptus grandis plantation area in Argentina. Stand density ranges from 1,000 to 1,111 plants/ha and 10-12 years rotation lenghts allow for a variety of end uses: pulp, sawmill, poles. Stand density effects on E. grandis growth were evaluated in a trial network across the Entre Ríos province. Three Nelder-designed trials were periodically measured for DBH and height up to age ten years. With increasing density, basal area decreased and DBH, mean height and survival increased; quadratic regression equations indicated that spacing explained 60 to 76 p. 100 of the variation in DBH and basal area. Results allow for the following management recommendations; stand density has to be decreased in low quality sites; when a larger DBH is the objective, stand density has to be lower and/or rotation length has to be increased and/or thinnings have to be applied; to produce larger DBHs than those currently consumed by sawmills will require a lower initial stand density or intermediate thinnings; a maximization of the final stand volume will be obtained with higher stand densities than those currently used.

Evaluation of Job Rotation Effects on Chain Saw Operators

This paper analyses the effects of job rotation on physical effort in chain saw operations. This study was conducted in a seven-year old Eucalyptus grandis plantation harvested with a short-wood clearcut system. A practical application of ergonomie principles was utilized, considering heart rate as the method to evaluate the heaviness of work. Data were collected in a situation where the chain saw operator and his assistant rotated primary tasks to reduce physiological workload. Piling logs was the most demanding activity for the assistant, while the chain saw operator primarily is exposed to chain saw noise and vibration. Rotating jobs on this situation did not significantly reduce the total physiological workload on saw operators.

Nutritional effects of Eucalyptus litter on the growth of maize ( Zea mays)

The effects of Eucalyptus leaf litter on the germination, nutrition and growth of maize were studied. Foliar extracts from Eucalyptus leaf litter inhibited maize germination. Germination was good in pots but growth of the first maize crop was reduced by about 68% by application of Eucalyptus leaf litter. Opposite results were obtained in a second maize crop planted in the same soil which showed an increase of 97% in shoot dry weight compared with the untreated control. Retardation of maize growth in the first cycle was inhibited mostly by nutrient immobilisation. Significant correlations were found between total N and P uptake and growth of maize. The concentration of these elements in maize from unmulched soil at the second crop was about twice that in the first crop. Field studies were conducted to compare some soil chemical properties of a field under a Eucalyptus grandis plantation and a woodland dominated by Brachystegia spiciformis (miombo woodland). The soil under Eucalyptus had more organic matter, NH 4N, Ca and P than the collected under miombo woodland. The latter had higher NO 3N, K, Mg and pH. Most of the nutrients were concentrated at a depth of between 0 and 5 cm with an accumulation of soil organic matter, P, Mg and K at a depth of between 40 and 50 cm. Although the growth of maize was much better in soils collected between 0 and 10 cm in the miombo woodland, no significant correlation was obtained between various nutrient elements measured at different depths and growth of maize with the exception of the higher NO 3N supply.

Predicting Tree Heights to Supplement Stand Tables of Eucalyptus Grandis

SYNOPSIS An equation is presented to predict the average height of trees with a given DBH and age in Eucalyptus grandis plantations. The estimated height can be proportionately weighted to adjust the estimate in order to account for different site qualities. Having the height by diameter class permits calculation of stand volume by diameter or product class, thus improving precision.

The verification of the heat pulse velocity technique for estimating sap flow in Eucalyptusgrandis

The heat pulse velocity technique was verified on a diffuse porous hardwood, Eucalyptusgrandis Hill ex. Maiden, using the cut-tree method. The heat pulse velocity apparatus accurately reflected sap flow in the stems of 3-year-old trees and of a 16-year-old tree. Measured sap flow was found to be particularly sensitive to errors in the estimation of the wound size and probe separation. Four probes, each providing a point estimate of heat pulse velocity, were sufficient to estimate sap flow in young trees, but a minimum of eight was needed for trees larger than about 20 cm in diameter. For the successful field application of the heat pulse velocity technique on standing E. grandis trees, it is necessary to wait 5 days after implanting the probes to enable tyloses to form, which facilitates wound size measurement. This technique is recommended for the accurate and rapid measurement of water use by E. grandis and other similar plantation tree species.

Growth, Yield and Timber Density of Short Rotation Coppice Stands ofEucalyptus grandis

SUMMARY The effects of timing initial coppice reductions, number of reductions and final number of shoots per stool on growth and yield of Eucalyptus grandis are described. The basic data were obtained from three experiments situated in different climatic zones of the summer rainfall area of South Africa. The influence of site differences, stand densities, mortality and factorial treatments on timber yield and timber density are compared at harvesting at about 10 and 14 years of age. The relationships of yield and timber density of the parent seedling crops and those of the coppice crops are investigated and the influence of different growth rates due to prevailing climate and management are analysed. The importance of basal area as a predictor variable of yield at harvesting for the wide range of treatment interactions is indicated. On the basis of these results and observations in commercial plantations, practical recommendations are given for the management of E. grandis plantations grown from coppice ...

Ecologie et évolution des jardins de fourmis en Guyane Française

Ant gardens were followed intermittently, from 1986 to 1989, in a Citrus grandis plantation and in a lowland rain forest, at the Piste de St Elie study site, French Guiana. This plant-ant asociation most likely originates in a different way in open and closed environments. Whereas the plant partner settles first on a tree in a plantation, the ants secondarily entering the root-ball to build their nest, the ant partner is the first settler on rainf orest trees, epiphytes later establishing themselves on their nests. The number of plant partners in an ant garden ranged from 1 to 5 species in the hundreds of gardens studied. They belonged mostly to a limited number of epiphytic families : Araceae, Bromeliaceae, Gesneriaceae, and Peperomiaceae. The ant partners were less numerous in species (1 to 3), belonging to genera Camponotus and Crematogaster. Ant gardens in tree plantations, forest edges, or river sides were composed of more plant species than those found in rain forests. The number of plant partners also increased with the size and age of the ant garden. No specific plant-ant association was ever found in the ant gardens examined. When Anthurium gracile was the only plant partner, there was also a single ant associate, but it was seldom the same, strongly suggesting that the association is initiated at random. In 50 % of the ant gardens studied, whatever the environment, there were two different ant partners per garden. Seven categories of plant-ant associations were recognized. A single tree could harbour as many as 10 ant gardens of different composition. The growth of a new aggregation of ant gardens was studied from 1986 to 1989 in a Citrus plantation, after destruction of all pre-existing associations. The establishment of new ant-gardens was very rapid, and took place within a single year. The major factors influencing their establishment were a sufficient amount of light, and the structure of the bark of the supporting tree. Too much shade and an abundance of epiphytic moss were obviously unsuitable conditions. In the Citrus plantation, ant gardens increased more rapidly in numbers and size on the trees grown on well drained soils ; conversely, they were less abundant on stunted, moss covered, trees planted in hydromorphic soils. Under favourable conditions, the number of ant gardens in Citrus plantations can become impressive : 1015 were enumerated on 456 trees in 1989, three years after complete clearance of all previous gardens ! Both plants and ants take advantage of their association in an ant garden. The plant partner benefits from the nutrients provided by the humus of the root-ball and the decomposing detritus of the ant nest. They also take advantage of the active protection afforded by their aggressive ant partners. Their seeds may also be dispersed by the ants within and around the garden. The ants also greatly benefit throughout the year from the secretions of the floral and extra-floral nectaries of their plant associates, and from the pulp of their fleshy fruits. The intricate root system of the epiphytes also provides shelter and reinf orcement to the brood chambers. An ant garden largely functions in isolation. Contrary to most true myrme-cophytes still deriving most of their necessary nutrients from the soil, ant associated epiphytes no longer depend on the soil substrate. All the necessary nutrients are provided by the enriched humus surrounding the arboreal ant nest(s).

Nutrient Cycling in a New South Wales Subtropical Rainforest: Organic Matter and Phosphorus

Biomass and phosphorus distribution and accumulation rates were estimated for an undisturbed subtropical rainforest in northern New South Wales. The accumulation rates were estimated over a 16-year period. It is estimated that the steady-state above-ground biomass for this forest is 35.0 tonne ha−1. Most of the annual biomass production was replacing litterfall and mortality. The above-ground forest contained 52 kg P ha−1 with a gross annual accumulation of about 0.4 kg P ha−1/yr−1. The forest understorey and forest floor contained 4.7 kg P ha−1 and 7.9 kg P ha−1, respectively. The annual uptake was approx. 4 kg P ha−1 yr−1. The phosphorus utilization of this stand was compared with that of a Eucalyptus grandis plantation

Basal Cankers and Coppice Failure of Eucalyptus grandis in Florida

Barnard. E. L.. Geary. T.. English,J. T.,and Gilly, S. P. 1987. Basal cankers and coppice failure of Euca/yplus grandis in Florida. Plant Disease 71: 358-361. of Eucalyptus spp. in Brazil and Surinam, respectively, and have reduced coppicing substantially (4,13,14). We have suspected that C. cubensis was a cause of some, if not all, coppice failure of E. grandis in Florida (Fig. 1). Therefore, we surveyed for basal cankers in an 11-yr-old E. grandis plantation that had been studied earlier by Hodges et al (12), isolated from cankered tissues to identify associated fungi, and evaluated coppice regeneration in the plantation after it was harvested at age 13. Preliminary observations from the canker survey have been reported (1). The relationship of basal cankers to coppice failure in a Euca/yptus grandis plantation in southern Florida was investigated. Canker incidence increased from about 15 to 57% over 4 yr. Cr.vphonectria cubensis and Botryosphaeria dothidea were isolated frequently from bark samples removed from cankered trees and stumps. After a February harvest at age 13, 44% of residual stumps failed to generate coppice shoots, or they initiated new shoots that soon died. Incidence of coppice failure was not significantly correlated to the presence or severity of basal cankers, but stumps of cankered trees had significantly fewer coppice-bursting centers. Dead coppice shoots on 99 of 100 randomly selected stumps supported pycnidia and/ or perithecia of c. cubensis at their bases 18 mo after harvest. Dead coppice shoots on 50 of the same 100 stumps supported pycnidial stromata characteristic of those described for C. gyrosa, a species not previously reported in

Organic matter accumulation in a series of Eucalyptus grandis plantations

The biomass and net productivity of a series of stands in Eucalyptus grandis plantations on the north coast of New South Wales were studied. The stands were of various ages but soil nutrient differences did not allow them to be directly considered as a chronosequence. To further assess the variation involved, relationships between soil phosphorus and site quality were developed ( R 2 = 0.89). Net annual increment ranged from 1880 to 16 435 kg ha −1 yr −1, total litterfall ranged from 7305 to 8740 kg ha −1 yr −1, and net aboveground productivity ranged from 9475 to 24 740 kg ha −1 yr −1. Litter layer mass remained relatively constant during the study period but the relative turnover of the forest floor assessed by the k factor was very rapid. Using long term growth data, a generalized net biomass accumulation curve was developed to be used for long term nutrient accumulation studies in New South Wales E. grandis plantations.

Habitat preferences of the larger mammals in the Parambikulam Wildlife Sanctuary, Kerala, India

The habitat preferences of large and medium-sized mammals in the Parambikulam Wildlife Sanctuary were studied. Twenty-four species were recorded. Most prefer to live in specific forest types. In the case of primates, Macaca radiata was more abundant in forest plantations and in deciduous forests. Macaca silenus was cinfined to the evergreen forests alone. Presbytis entellus was more numerous in deciduous forests. Presbytis johni was more or less evenly distributed between the west coast tropical evergreen and moist deciduous forests. Herbivores and carnivores were most abundant in grasslands and in the Tectona grandis plantations.