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Full-Text Articles in Agronomy and Crop Sciences
Growth And Species Interactions Of Eucalyptus Pellita In A Mixed And Monoculture Plantation In The Humid Tropics Of North Queensland, Mila Bristow, Jerome K. Vanclay, Lyndon O. Brooks, Mark Hunt
Growth And Species Interactions Of Eucalyptus Pellita In A Mixed And Monoculture Plantation In The Humid Tropics Of North Queensland, Mila Bristow, Jerome K. Vanclay, Lyndon O. Brooks, Mark Hunt
Dr Lyndon O Brooks
This study investigated whether mixed-species designs can increase the growth of a tropical eucalypt when compared to monocultures. Monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) were planted in a replacement series design on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence …
Mixed Species Plantations: Prospects And Challenges, J Doland Nichols, Mila Bristow, Jerome K. Vanclay
Mixed Species Plantations: Prospects And Challenges, J Doland Nichols, Mila Bristow, Jerome K. Vanclay
Professor Jerome K Vanclay
About 2% of English-language literature on plantations deals with mixed-species plantations, but only a tiny proportion (<0.1%) of industrial plantations are polycultures. Small landholders are more innovative, with 12% of Australia’s farm forestry plantations under mixed-species plantings, and 80% of Queensland’s farm forestry as polycultures. We examine reasons for this discrepancy, and explore the history, silviculture and economics of polycultures. Financial analyses suggest that a yield stimulus of 10%, depending on product and rotation length, may be sufficient to offset increased costs associated with planting and managing a mixed-species plantation, a stimulus that has been demonstrated in many field …
Mixed-Species Plantation Of Eucalyptus With Nitrogen Fixing Trees: A Review, David I. Forrester, Jürgen Bauhus, Annette L. Cowie, Jerome K. Vanclay
Mixed-Species Plantation Of Eucalyptus With Nitrogen Fixing Trees: A Review, David I. Forrester, Jürgen Bauhus, Annette L. Cowie, Jerome K. Vanclay
Professor Jerome K Vanclay
Mixed-species plantations of Eucalyptus with a nitrogen (N2) fixing species have the potential to increase productivity while maintaining soil fertility, compared to Eucalyptus monocultures. However, it is difficult to predict combinations of species and sites that will lead to these benefits. We review the processes and interactions occurring in mixed plantations, and the influence of species or site attributes, to aid the selection of successful combinations of species and sites. Successful mixtures, where productivity is increased over that of monocultures, have often developed stratified canopies, such that the less shade-tolerant species overtops the more shade-tolerant species. Successful mixtures also have …
Growth And Species Interactions Of Eucalyptus Pellita In A Mixed And Monoculture Plantation In The Humid Tropics Of North Queensland, Mila Bristow, Jerome K. Vanclay, Lyndon O. Brooks, Mark Hunt
Growth And Species Interactions Of Eucalyptus Pellita In A Mixed And Monoculture Plantation In The Humid Tropics Of North Queensland, Mila Bristow, Jerome K. Vanclay, Lyndon O. Brooks, Mark Hunt
Professor Jerome K Vanclay
This study investigated whether mixed-species designs can increase the growth of a tropical eucalypt when compared to monocultures. Monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) were planted in a replacement series design on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence …
Forest Dynamics In Flood Plain Forests In The Peruvian Amazon: Effects Of Disturbance And Implications For Management, Gustav Nebel, Lars Peter Kvist, Jerome K. Vanclay, Hector Vidaurre
Forest Dynamics In Flood Plain Forests In The Peruvian Amazon: Effects Of Disturbance And Implications For Management, Gustav Nebel, Lars Peter Kvist, Jerome K. Vanclay, Hector Vidaurre
Professor Jerome K Vanclay
Forest dynamics were studied from 1993 to 1997 for individuals > 10 cm DBH in nine 1 ha permanent sample plots. They were established in natural flood plain forests located on the lower Ucayali river in the Peruvian Amazon. After inventories of three plots in each of three forest types, a light and a heavy felling treatment were applied to each of the two plots, while a third plot was kept untreated. Average annual stem mortality and recruitment rates in the untreated plots were among the highest observed in neotropical rain forests: mortality 2.2-3.2% per year, recruitment 3.0-4.6% per year. Dead …
Experiment Designs To Evaluate Inter- And Intra-Specific Interactions In Mixed Plantings Of Forest Trees, Jerome K. Vanclay
Experiment Designs To Evaluate Inter- And Intra-Specific Interactions In Mixed Plantings Of Forest Trees, Jerome K. Vanclay
Professor Jerome K Vanclay
A review of three mixed-species trials reveals the utility of competition indices for evaluating inter- and intra-specific interactions between trees, the desirability of experiments that span a range of tree spacing and composition to inform calibration of these competition indices, the need for extremes of species composition and stand density to calibrate response surfaces, and the far-reaching impact of edge-effects. Experiment layouts commonly used for mixed-species trials in forestry (such as replacement series) rarely provide a strong basis to calibrate competition indices and response surfaces. Alternative designs involving systematic changes in species composition may offer a better basis for calibrating …
Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko
Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko
Pr. Mamoudou H. DICKO, PhD
The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is …
Forest Dynamics In Flood Plain Forests In The Peruvian Amazon: Effects Of Disturbance And Implications For Management, Gustav Nebel, Lars Peter Kvist, Jerome K. Vanclay, Hector Vidaurre
Forest Dynamics In Flood Plain Forests In The Peruvian Amazon: Effects Of Disturbance And Implications For Management, Gustav Nebel, Lars Peter Kvist, Jerome K. Vanclay, Hector Vidaurre
Professor Jerome K Vanclay
Forest dynamics were studied from 1993 to 1997 for individuals > 10 cm DBH in nine 1 ha permanent sample plots. They were established in natural flood plain forests located on the lower Ucayali river in the Peruvian Amazon. After inventories of three plots in each of three forest types, a light and a heavy felling treatment were applied to each of the two plots, while a third plot was kept untreated. Average annual stem mortality and recruitment rates in the untreated plots were among the highest observed in neotropical rain forests: mortality 2.2-3.2% per year, recruitment 3.0-4.6% per year. Dead …