L. Amissah - Academia.edu (original) (raw)
Papers by L. Amissah
Tropical forests occur along a rainfall gradient where annual amount, the length and intensity of... more Tropical forests occur along a rainfall gradient where annual amount, the length and intensity of dry season vary and water availability shapes therefore strongly the distribution of tree species. Annual rainfall in West Africa has declined at a rate of 4% per decade, and climate change models predict a further reduction in rainfall and an increase in frequency and intensity of drought. This will have large consequences for the diversity, composition and distribution of tropical tree species. Understanding the factors that shape tree species distribution will help to understand current forest functioning and to predict the potential impact of climate change on forests. In this thesis, I used a combination of forest inventory data, greenhouse and field experiments to determine the responses of 10-23 species to drought and shade, and analyse the underlying mechanisms. I addressed 4 questions: (1) What is the relative importance of rainfall and temperature on tree species distribution?...
Ghana Journal of Forestry, 2012
Wildfires as dominant force driving farming systems in the forest transition zone of Ghana.
Global Change Biology, 2021
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Ghana Journal of Forestry, 2011
Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have ... more Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have been blamed on farmers practicing slash and burn agriculture. In addition, many critics have assumed that farmers have very limited knowledge of fire management and therefore do not manage farming-related fires. A survey was conducted in eight communities in the forest transition zone to assess the perceptions of farmers on farming-related wildfire incidences, specific activities in farming associated with incidence of wildfires and coping measures being used by farmers to manage wildfires. Farmers in the studied settlements hold the view that there are presently certain cropping practices that are closely associated with wildfire incidence. These include early vegetable and yam cultivation whereby the burning of slash takes place between December and February when fire risk is high. The study also found that farmers have useful knowledge in wildfire management and are applying it to cope with the impacts of wildfires. Some of the important coping strategies are farm maintenance practices, fire prevention education and precautionary measures during land preparation. Adopted measures by farmers need to be supported by research and agriculture extension to remove weaknesses in farmers' efforts.
Cite as: Bosu, P. P., Apetorgbor, M. M., Amissah, L. and Mutta, D. 2019. Status, trends and impac... more Cite as: Bosu, P. P., Apetorgbor, M. M., Amissah, L. and Mutta, D. 2019. Status, trends and impacts of forest and tree pests in West and Central Africa. African Journal of Rural Development 4 (1): 93-107. Received: 14 August 2018 Accepted: 26 February 2019 Published: 31 March 2019 ABSTRACT There is considerable drive in many countries of West and Central Africa towards reforestation and rehabilitation initiatives that use trees. However, the occurrence of pests and diseases in Africa is having considerable impact on forest growth and yield and thus reducing profits from forests. Consequently, measures to protect forests from pests and diseases should be an integral part of sustainable forest management. The objective of the study was to evaluate the status and trends of forest and tree pests and disease management in the West and Central African regions with the view to proposing appropriate control measures, including development of protocols for pest and disease surveillance. A co...
PloS one, 2015
In tropical forests light and water availability are the most important factors for seedling grow... more In tropical forests light and water availability are the most important factors for seedling growth and survival but an increasing frequency of drought may affect tree regeneration. One central question is whether drought and shade have interactive effects on seedling growth and survival. Here, we present results of a greenhouse experiment, in which seedlings of 10 Ghanaian tree species were exposed to combinations of strong seasonal drought (continuous watering versus withholding water for nine weeks) and shade (5% irradiance versus 20% irradiance). We evaluated the effects of drought and shade on seedling survival and growth and plasticity of 11 underlying traits related to biomass allocation, morphology and physiology. Seedling survival under dry conditions was higher in shade than in high light, thus providing support for the "facilitation hypothesis" that shade enhances plant performance through improved microclimatic conditions, and rejecting the trade-off hypothesis...
Ghana Journal of Forestry, 2011
Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have ... more Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have been blamed on farmers practicing slash and burn agriculture. In addition, many critics have assumed that farmers have very limited knowledge of fire management and therefore do not manage farming-related fires. A survey was conducted in eight communities in the forest transition zone to assess the perceptions of farmers on farming-related wildfire incidences, specific activities in farming associated with incidence of wildfires and coping measures being used by farmers to manage wildfires. Farmers in the studied settlements hold the view that there are presently certain cropping practices that are closely associated with wildfire incidence. These include early vegetable and yam cultivation whereby the burning of slash takes place between December and February when fire risk is high. The study also found that farmers have useful knowledge in wildfire management and are applying it to cope with the impacts of wildfires. Some of the important coping strategies are farm maintenance practices, fire prevention education and precautionary measures during land preparation. Adopted measures by farmers need to be supported by research and agriculture extension to remove weaknesses in farmers' efforts.
Tropical forests occur along a rainfall gradient where annual amount, the length and intensity of... more Tropical forests occur along a rainfall gradient where annual amount, the length and intensity of dry season vary and water availability shapes therefore strongly the distribution of tree species. Annual rainfall in West Africa has declined at a rate of 4% per decade, and climate change models predict a further reduction in rainfall and an increase in frequency and intensity of drought. This will have large consequences for the diversity, composition and distribution of tropical tree species. Understanding the factors that shape tree species distribution will help to understand current forest functioning and to predict the potential impact of climate change on forests. In this thesis, I used a combination of forest inventory data, greenhouse and field experiments to determine the responses of 10-23 species to drought and shade, and analyse the underlying mechanisms. I addressed 4 questions: (1) What is the relative importance of rainfall and temperature on tree species distribution?...
Ghana Journal of Forestry, 2012
Wildfires as dominant force driving farming systems in the forest transition zone of Ghana.
Global Change Biology, 2021
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Ghana Journal of Forestry, 2011
Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have ... more Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have been blamed on farmers practicing slash and burn agriculture. In addition, many critics have assumed that farmers have very limited knowledge of fire management and therefore do not manage farming-related fires. A survey was conducted in eight communities in the forest transition zone to assess the perceptions of farmers on farming-related wildfire incidences, specific activities in farming associated with incidence of wildfires and coping measures being used by farmers to manage wildfires. Farmers in the studied settlements hold the view that there are presently certain cropping practices that are closely associated with wildfire incidence. These include early vegetable and yam cultivation whereby the burning of slash takes place between December and February when fire risk is high. The study also found that farmers have useful knowledge in wildfire management and are applying it to cope with the impacts of wildfires. Some of the important coping strategies are farm maintenance practices, fire prevention education and precautionary measures during land preparation. Adopted measures by farmers need to be supported by research and agriculture extension to remove weaknesses in farmers' efforts.
Cite as: Bosu, P. P., Apetorgbor, M. M., Amissah, L. and Mutta, D. 2019. Status, trends and impac... more Cite as: Bosu, P. P., Apetorgbor, M. M., Amissah, L. and Mutta, D. 2019. Status, trends and impacts of forest and tree pests in West and Central Africa. African Journal of Rural Development 4 (1): 93-107. Received: 14 August 2018 Accepted: 26 February 2019 Published: 31 March 2019 ABSTRACT There is considerable drive in many countries of West and Central Africa towards reforestation and rehabilitation initiatives that use trees. However, the occurrence of pests and diseases in Africa is having considerable impact on forest growth and yield and thus reducing profits from forests. Consequently, measures to protect forests from pests and diseases should be an integral part of sustainable forest management. The objective of the study was to evaluate the status and trends of forest and tree pests and disease management in the West and Central African regions with the view to proposing appropriate control measures, including development of protocols for pest and disease surveillance. A co...
PloS one, 2015
In tropical forests light and water availability are the most important factors for seedling grow... more In tropical forests light and water availability are the most important factors for seedling growth and survival but an increasing frequency of drought may affect tree regeneration. One central question is whether drought and shade have interactive effects on seedling growth and survival. Here, we present results of a greenhouse experiment, in which seedlings of 10 Ghanaian tree species were exposed to combinations of strong seasonal drought (continuous watering versus withholding water for nine weeks) and shade (5% irradiance versus 20% irradiance). We evaluated the effects of drought and shade on seedling survival and growth and plasticity of 11 underlying traits related to biomass allocation, morphology and physiology. Seedling survival under dry conditions was higher in shade than in high light, thus providing support for the "facilitation hypothesis" that shade enhances plant performance through improved microclimatic conditions, and rejecting the trade-off hypothesis...
Ghana Journal of Forestry, 2011
Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have ... more Forests in Ghana are increasingly being influenced by man-caused fires. Most of these fires have been blamed on farmers practicing slash and burn agriculture. In addition, many critics have assumed that farmers have very limited knowledge of fire management and therefore do not manage farming-related fires. A survey was conducted in eight communities in the forest transition zone to assess the perceptions of farmers on farming-related wildfire incidences, specific activities in farming associated with incidence of wildfires and coping measures being used by farmers to manage wildfires. Farmers in the studied settlements hold the view that there are presently certain cropping practices that are closely associated with wildfire incidence. These include early vegetable and yam cultivation whereby the burning of slash takes place between December and February when fire risk is high. The study also found that farmers have useful knowledge in wildfire management and are applying it to cope with the impacts of wildfires. Some of the important coping strategies are farm maintenance practices, fire prevention education and precautionary measures during land preparation. Adopted measures by farmers need to be supported by research and agriculture extension to remove weaknesses in farmers' efforts.