Bark stripping and population dynamics of baboon troops after chemical control in pine plantations of Zimbabwe

2006 ◽  
Vol 44 (3) ◽  
pp. 413-416 ◽  
Author(s):  
C. A. T. Katsvanga ◽  
S. M. Mudyiwa ◽  
D. Gwenzi
Keyword(s):  
Population Dynamics ◽  
Chemical Control ◽  
Pine Plantations ◽  
Bark Stripping

Modelling the susceptibility of pine stands to bark stripping by Chacma baboons (Papio ursinus) in the Mpumalanga Province of South Africa

2017 ◽  
Vol 44 (4) ◽  
pp. 298 ◽  
Author(s):  
Ilaria Germishuizen ◽  
Kabir Peerbhay ◽  
Riyad Ismail
Keyword(s):  
South Africa ◽  
Random Forests ◽  
Risk Evaluation ◽  
Site Index ◽  
Pine Plantations ◽  
Bark Stripping ◽  
Papio Ursinus ◽  
Mpumalanga Province ◽  
Chacma Baboons ◽  
Pinus Spp

Context Commercial pine (Pinus spp.) plantations in southern Africa have been subjected to bark stripping by Chacma baboons (Papio ursinus) for many decades, resulting in severe financial losses to producers. The drivers of this behaviour are not fully understood and have been partially attributed to resource distribution and availability. Aims The study sought to develop a spatially explicit ecological-risk model for bark stripping by baboons to understand the environmental factors associated with the presence of damage in the pine plantations of the Mpumalanga province of South Africa. Methods The model was developed in Random Forests, a machine learning algorithm. Baboon damage information was collected through systematic surveys of forest plantations conducted annually. Environmental predictors included aspects of climate, topography and compartment-specific attributes. The model was applied to the pine plantations of the study area for risk evaluation. Key results The Random Forests classifier was successful in predicting damage occurrence (F1 score=0.84, area under curve (AUC)=0.96). Variable predictors that contributed most to the model classification accuracy were related to pine-stand characteristics, with the age of trees being the most important predictor, followed by species, site index and altitude. Variables pertaining to the environment surrounding a pine stand did not contribute substantially to the model performance. Key conclusions (1) The study suggests that bark stripping is influenced by compartment attributes; (2) predicted risk of bark stripping is higher in stands above the age of 5 years planted on high-productivity forestry sites, where site index (SI) is above 25; (3) presence of damage is not related to the proximity to natural areas; (4) further studies are required to investigate ecological and behavioural patterns associated with bark stripping. Implications The model provides a tool for understanding the potential extent of the risk of bark stripping by baboons within this region and it can be applied to other forestry areas in South Africa for risk evaluation. It contributes towards the assessment of natural hazards potentially affecting pine plantations and supports the development of risk-management strategies by forest managers. The model highlights opportunities for cultural interventions that may be tested for damage control.

scholarly journals Biological and chemical control of nematodes in Capsicum annuum L.

1969 ◽  
Vol 76 (3-4) ◽  
pp. 171-176
Author(s):  
Nydia E. Vicente ◽  
Nelia Acosta
Keyword(s):  
Population Dynamics ◽  
Field Experiment ◽  
Capsicum Annuum ◽  
Chemical Control ◽  
Nematode Population ◽  
Capsicum Annuum L

A field experiment was conducted at the Isabela substation. The objective of the study was to compare the effect of the fungus P. lilacinus (added 1 week before planting or at planting) and the nematicide carbofuran (1X or 2X) on yields of pepper and on the population fevels of M. incognita and R. reniformis. Significantly more and heavier fruits were obtained from fungus (1 week before planting)-and carbofuran 2X-treated plots than from the check. A similar trend was observed in the nematode population dynamics; although the percentage of nematode reduction was high in all treated plots, it was higher in those treated with the fungus 1 week before planting and with carbofuran 2X.

CARROT YIELD INCREASES AFTER CHEMICAL CONTROL OF ROOT-KNOT NEMATODE IN ORGANIC SOIL

1981 ◽  
Vol 61 (3) ◽  
pp. 677-682 ◽  
Author(s):  
T. C. VRAIN ◽  
Y. FOURNIER ◽  
R. CRETE
Keyword(s):  
Population Dynamics ◽  
Chemical Control ◽  
Organic Soil ◽  
Infested Soil ◽  
Nematode Control ◽  
Significant Protection ◽  
Root Knot Nematode ◽  
Marketable Yield ◽  
Daucus Carota L ◽  
Soil Fumigants

In root-knot nematode-infested soil, post-treatment effects of nematicides on duration of acceptable yields of marketable carrots (Daucus carota L.) and on nematode population dynamics were determined. These studies included a comparison of the efficacy of granular nematicides and soil fumigants. Surviving nematodes multiplied and caused unacceptable losses 2 yr after fumigation. Fumigation with Telone, D.D. or Vorlex gave the best nematode control and the highest marketable yield. Oxamyl, aldicarb and fosthietan gave a significant protection of carrots at doses of 3 and 6 kg a.i./ha. Bunema, phenamiphos and carbofuran were the least effective.

scholarly journals Influence of abiotic factors on the resistance of plants to insects

2019 ◽  
Vol 12 (1) ◽  
pp. 01-05 ◽  
Author(s):  
Ciro Pedro Guidotti Pinto ◽  
Sabrina Ongaratto
Keyword(s):  
Population Dynamics ◽  
Soil Fertility ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Plant Resistance ◽  
Chemical Control ◽  
Abiotic Factors ◽  
Insect Herbivory ◽  
Direct Influence ◽  
Insect Population Dynamics

Abstract. Plant resistance is considered as an important pillar of Integrated Pest Management (IPM), being a highly targeted method since is a less harmful method to the environment, if compared to other tactics such as chemical control. Abiotic factors are those related to the environment and have a direct influence on the dynamics of interaction between insects and plants. The abiotic factors such as altitude, temperature, humidity, luminosity, wind and soil fertility, among others, do not act alone, but in a complex net that leads insect population dynamics in agroecosystems. How the variations of these factors can be studied in the same context? First, it is important to consider how each abiotic factors act separately and then in a coexistence influence over the populations dynamics of insects and plants. In this study, the literature about the influence of abiotic factors on insect herbivory has been reviewed, focusing mainly on the mechanisms in which the plants use in the defense against insects.Influência de fatores abióticos na resistência de plantas a insetos Resumo. A resistência de plantas é considerada um importante pilar no contexto do Manejo Integrado de Pragas (MIP), sendo um método bastante visado por ser menos nocivo ao meio ambiente, quando comparado a outras táticas como o controle químico. Os fatores abióticos são aqueles relacionados ao ambiente e têm influência direta na dinâmica de interação entre insetos e plantas. Os fatores abióticos como altitude, temperatura, umidade, luminosidade, ventos e fertilidade do solo, por exemplo, não atuam sozinhos, mais sim em um complexo de fatores coexistentes que regem as dinâmicas populacionais nos diversos agroecosistemas. Como as variações destes fatores podem ser estudadas em um mesmo contexto? Primeiramente, é importante conhecer como cada uma atua individualmente para então contextualizar em uma situação de coexistência sobre as dinâmicas populacionais de insetos e plantas. Neste artigo, a literatura sobre a influência de fatores abióticos na herbivoria de insetos foi revisada, focando principalmente nos mecanismos em que as plantas utilizam na defesa contra insetos.

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