Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578259
Title: Modelling microclimates in broadleaved deciduous forests using remotely-sensed data
Author: Latif, Zulkiflee Abd
Awarding Body: Lancaster University
Current Institution: Lancaster University
Date of Award: 2010
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Abstract:
In temperate forests, wind throw often creates canopy gaps which can dramatically change the micro climate and soil water balance. The main focus of this thesis is to understand the spatio-temporal dynamics of the microclimatic conditions in gaps and the sub-canopy in broadleaved deciduous forests. This was achieved by applying a combination of numerical modelling and remote sensing techniques. An analysis of the effects of canopy gap size on microclimate and soil water content was conducted in a semi-natural broadleaved deciduous forest, Eaves Wood, located in North West England. The results showed that solar radiation, air temperature, soil temperature and soil water content significantly increased with gap size; air humidity was consistently lower in gaps than the sub-canopy but did not vary with gap size. However, the variability of wind speed could not be explained by the presence or size of gaps. A spatially explicit model of forest gap microclimate and soil water balance, FORGAP-BD (FORest GAP - Broadleaved Deciduous) was developed based on previous reviewed literatures and field measurements. The spatial input variables for FORGAP-BD such as leaf area index, land surface elevation, gap and canopy properties and canopy radiation extinction coefficient were derived from LiDAR and multi spectral remotely sensed data. A preliminary study demonstrated the effectiveness of combining numerical modelling and remote sensing approaches for analysis of the spatio-temporal variability of forest microclimate and soil water balance. Refinements were made to the methodologies for extracting canopy and gap properties using LiDAR and multi spectral data, in order to improve the gap microclimate and soil water content simulations. The outputs of the FORGAP-BD model were then validated using in situ data collected at Eaves Wood, U.K. The results demonstrated that FORGAP-BD driven by remotely-sensed inputs was able to accurately simulate the diurnal fluctuations and spatial distribution of solar radiation, air temperature, relative humidity, wind speed and soil water content across the study site. Multi-temporal LiDAR data were used to characterise the dynamics of gaps over a ten year period for a broadleaved deciduous forest, Frame Wood, U.K. The dominance of the process of gap contraction by lateral crown expansion was revealed. The spatial outputs from the multi-temporal remotely-sensed data were used to drive the FORGAP-BD model in order to assess the influence of gap dynamics on micro climate. The effects of different types of gap and canopy change were examined. Importantly, by linking gap properties and their influences upon microclimates this research has generated a potentially valuable tool for understanding the consequences of gap dynamics on a range of abiotic and biotic properties and processes. Hence, the approach developed here provides the basis on which to assess the implications of forestry and conservation practices and natural or anthropogenic disturbances in temperate forest ecosystems.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.578259  DOI: Not available
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