Analysis of simulated functional diversity in tropical forests: Differences between cultivated and naturally grown secondary forests in Cambodia
(2023) In Student thesis series INES NGEM01 20222Dept of Physical Geography and Ecosystem Science
- Abstract
- Accelerated deforestation represents a major global environmental concern. Over the last decades Cambodia has experienced a drastic decrease in forest cover and measures to halt deforestation have not been as effective as planned. In order to support reforestation, as well as appropriate sustainable forest management practices, two aspects need to be taken into account: (a) the ecosystem functioning of the forest, thus its ability to promote productivity and resist disturbances, and (b) the influence of harvest measures on the forest dynamics.
For this study the dynamic vegetation model LPJ-GUESS was applied to simulate specific scenarios of the forests in four study sites in Cambodia, representing evergreen, semi-evergreen and... (More) - Accelerated deforestation represents a major global environmental concern. Over the last decades Cambodia has experienced a drastic decrease in forest cover and measures to halt deforestation have not been as effective as planned. In order to support reforestation, as well as appropriate sustainable forest management practices, two aspects need to be taken into account: (a) the ecosystem functioning of the forest, thus its ability to promote productivity and resist disturbances, and (b) the influence of harvest measures on the forest dynamics.
For this study the dynamic vegetation model LPJ-GUESS was applied to simulate specific scenarios of the forests in four study sites in Cambodia, representing evergreen, semi-evergreen and deciduous forest covers. The functional diversity, expressed by the community-weighted mean of the analyzed plant functional traits, represents a suitable indicator to describe the performance of plant growth and the dynamics between the species within a forest ecosystem. Based on this model analysis, a difference in functional diversity between the old-growth, cultivated and naturally regrown forest ecosystems could be detected. In relation to the establishment and composition of the modelled group-specific plant functional types, the results suggest an overall dominance of shade tolerant and evergreen trees, emphasizing the advantage of longer leaf life-spans in hot and humid conditions. It is assumed that in three study sites (Koh Kong, Mondulkiri, and Takeo) the secondary forests show an overall higher ability to resist disturbances than the forests in Siem Reap. The extent of impacts of logging practices on biomass production depend on the interval and harvest intensity. Thinning processes of 10% conducted every 20 years tend to increase the forests’ overall carbon stock, indicating a positive effect of minor disturbances on the forest’s productivity. However, comparisons with self-derived measurements suggest an overestimation of the simulated plant growth, which requires further research to allow for specific recommendations on forest management practices. (Less) - Popular Abstract
- Over the last decades Cambodia has experienced a drastic decrease in forest cover. Considering the importance of tropical forests this study aims for an improved understanding of the dynamics within tropical forests. Based on the results, recommendations of forest management practices that halt deforestation and promote reforestation shall be provided.
Due to the complexity of forest dynamics two aspects need to be taken into account: (a) a theoretical concept that describes the forest dynamics, and (b) the application of a model that can simulate forest dynamics. Forest dynamics are represented by the species’ growth strategy that describes whether a plant grows faster or slower to promote its competitive advantage or overall survival.... (More) - Over the last decades Cambodia has experienced a drastic decrease in forest cover. Considering the importance of tropical forests this study aims for an improved understanding of the dynamics within tropical forests. Based on the results, recommendations of forest management practices that halt deforestation and promote reforestation shall be provided.
Due to the complexity of forest dynamics two aspects need to be taken into account: (a) a theoretical concept that describes the forest dynamics, and (b) the application of a model that can simulate forest dynamics. Forest dynamics are represented by the species’ growth strategy that describes whether a plant grows faster or slower to promote its competitive advantage or overall survival. This information ultimately provides an insight into the state and health of a forest, thus its ability to respond to, and resist environmental changes.
In order to relate the model results with the conditions of the tropical forests in Cambodia, four study sites were selected that represent different forest covers (e.g. evergreen, deciduous). Specific information was measured on-site and used to adjust the model input to allow for more realistic model simulations and eventually recommendations for appropriate forest management practices. Furthermore, based on the assumption that sustainable management practices will only be implemented if economic returns are expected, the study further focuses on the impact of logging processes on the forest dynamics.
The study’s results suggest that evergreen trees show a greater advantage over deciduous trees, which represent the expected influence of the tropical hot and humid climate. In three study sites the species tend to grow slower and thus promote the survival strategy. This indicates an overall higher ability of the forests to resist environmental changes. It can further be concluded that logging processes of 10% every 20 years generally promote the forest development. However, due to the model’s overestimation of plant growth, the results need to be treated with caution. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9112790
- author
- Graf, Clarissa LU
- supervisor
-
- Stefan Olin LU
- organization
- course
- NGEM01 20222
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- physical geography, ecosystem analysis, functional diversity, plant functional traits, ecosystem modelling, secondary forest ecosystems, sustainable forest management, LPJ-GUESS
- publication/series
- Student thesis series INES
- report number
- 586
- language
- English
- id
- 9112790
- date added to LUP
- 2023-03-24 13:01:22
- date last changed
- 2023-03-24 13:01:22
@misc{9112790,
abstract = {{Accelerated deforestation represents a major global environmental concern. Over the last decades Cambodia has experienced a drastic decrease in forest cover and measures to halt deforestation have not been as effective as planned. In order to support reforestation, as well as appropriate sustainable forest management practices, two aspects need to be taken into account: (a) the ecosystem functioning of the forest, thus its ability to promote productivity and resist disturbances, and (b) the influence of harvest measures on the forest dynamics.
For this study the dynamic vegetation model LPJ-GUESS was applied to simulate specific scenarios of the forests in four study sites in Cambodia, representing evergreen, semi-evergreen and deciduous forest covers. The functional diversity, expressed by the community-weighted mean of the analyzed plant functional traits, represents a suitable indicator to describe the performance of plant growth and the dynamics between the species within a forest ecosystem. Based on this model analysis, a difference in functional diversity between the old-growth, cultivated and naturally regrown forest ecosystems could be detected. In relation to the establishment and composition of the modelled group-specific plant functional types, the results suggest an overall dominance of shade tolerant and evergreen trees, emphasizing the advantage of longer leaf life-spans in hot and humid conditions. It is assumed that in three study sites (Koh Kong, Mondulkiri, and Takeo) the secondary forests show an overall higher ability to resist disturbances than the forests in Siem Reap. The extent of impacts of logging practices on biomass production depend on the interval and harvest intensity. Thinning processes of 10% conducted every 20 years tend to increase the forests’ overall carbon stock, indicating a positive effect of minor disturbances on the forest’s productivity. However, comparisons with self-derived measurements suggest an overestimation of the simulated plant growth, which requires further research to allow for specific recommendations on forest management practices.}},
author = {{Graf, Clarissa}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{Analysis of simulated functional diversity in tropical forests: Differences between cultivated and naturally grown secondary forests in Cambodia}},
year = {{2023}},
}