title: Surface oscillation in peatlands: How variable and important is it?

authors: Fritz, Christian

subjects: hydrology

abstract: Hydrology, particularly the water table position below the surface, is an important control on biogeochemical and ecological processes in peatlands. The position of the water table is a function of total storage changes, drainable porosity and peatland surface oscillation (PSO). Because the absolute level of the peat surface (ASL) oscillates in a peatland, we can assign two different water table positions: the water table depth below the surface (relative water level, RWL) and the water table position above an absolute elevation datum eg. sea level (absolute water level, AWL). 

A review of 37 studies that report peatland surface oscillation indicate a wide range (0.4-55 cm), which is to the same order as (or one order smaller than) water storage changes and RWL fluctuations. PSO can vary substantially across a single peatland and through time. A set of mechanisms (flotation, compression/shrinkage, gas volume changes and freezing) is hypothesised to cause ASL changes. The potential of PSO to reduce RWL fluctuations trended (mean in %) floating peatlands (63) > bogs (21), fens (18) > disturbed peatlands (10) with respect to peatland types. 

To investigate the spatiotemporal variability of peatland surface oscillation, AWL and ASL were monitored continuously over a one-year period (one site) and monthly (23 sites) in a warm-temperate peatland that is dominated by Empodisma minus (Restionaceae). A new measurement method was developed by pairing two water level transducers, one attached to a stable benchmark (ÆAWL) and one attached to the peat surface (ÆRWL). 

From August 2005 until August 2006 the ASL oscillated at one site through a range of 22 cm following AWL fluctuations (in total 47 cm). Consequently, RWL fluctuations were reduced on average to 53% of AWL fluctuations. The strong AWL-ASL relationship was linear for 15 sites with manual measurements. However, eight sites showed significantly higher rates of peatland surface oscillation during the wet season (ie. high AWLs) and thus a non-linear behaviour. Temporary flotation of upper peat layers during the wet season may have caused this non-linear behaviour. On the peatland scale AWL fluctuations (mean 40 cm among sites) were reduced by 30–50% by PSO except for three sites with shallow and dense peat at the peatland margin (7–11%). The reduction of RWL fluctuation was high compared to literature values. The spatial variability of PSO seemed to match well with vegetation patterns rather than peat thickness or bulk density. Sites with large PSO showed high cover of Empodisma minus. 

Surface level changes exhibited surprisingly hysteretic behaviour subsequent to raised AWLs, when the rise of ASL was delayed. This delay reversed the positive ASL-AWL relationship because the surface slowly rose even though AWL started receding. Hysteresis was more pronounced during the dry season than during the wet season. The observed hysteresis can be sufficiently simulated by a simplistic model incorporating delayed ASL fluctuations. 

PSO has wide implications for peatland hydrology by reducing RWL fluctuations, which feed back to peat decomposition and plant cover and potentially to (drainable) porosity. Stable RWL also reduce the probability of surface run-off. It is further argued that the gas content of the roots of plants, particularly Empodisma minus, added enough buoyancy to detach the uppermost peat layers resulting in flotation.

text: Surface oscillation in peatlands: How variable and important is it? Hydrology, particularly the water table position below the surface, is an important control on biogeochemical and ecological processes in peatlands. The position of the water table is a function of total storage changes, drainable porosity and peatland surface oscillation (PSO). Because the absolute level of the peat surface (ASL) oscillates in a peatland, we can assign two different water table positions: the water table depth below the surface (relative water level, RWL) and the water table position above an absolute elevation datum eg. sea level (absolute water level, AWL). 

A review of 37 studies that report peatland surface oscillation indicate a wide range (0.4-55 cm), which is to the same order as (or one order smaller than) water storage changes and RWL fluctuations. PSO can vary substantially across a single peatland and through time. A set of mechanisms (flotation, compression/shrinkage, gas volume changes and freezing) is hypothesised to cause ASL changes. The potential of PSO to reduce RWL fluctuations trended (mean in %) floating peatlands (63) > bogs (21), fens (18) > disturbed peatlands (10) with respect to peatland types. 

To investigate the spatiotemporal variability of peatland surface oscillation, AWL and ASL were monitored continuously over a one-year period (one site) and monthly (23 sites) in a warm-temperate peatland that is dominated by Empodisma minus (Restionaceae). A new measurement method was developed by pairing two water level transducers, one attached to a stable benchmark (ÆAWL) and one attached to the peat surface (ÆRWL). 

From August 2005 until August 2006 the ASL oscillated at one site through a range of 22 cm following AWL fluctuations (in total 47 cm). Consequently, RWL fluctuations were reduced on average to 53% of AWL fluctuations. The strong AWL-ASL relationship was linear for 15 sites with manual measurements. However, eight sites showed significantly higher rates of peatland surface oscillation during the wet season (ie. high AWLs) and thus a non-linear behaviour. Temporary flotation of upper peat layers during the wet season may have caused this non-linear behaviour. On the peatland scale AWL fluctuations (mean 40 cm among sites) were reduced by 30–50% by PSO except for three sites with shallow and dense peat at the peatland margin (7–11%). The reduction of RWL fluctuation was high compared to literature values. The spatial variability of PSO seemed to match well with vegetation patterns rather than peat thickness or bulk density. Sites with large PSO showed high cover of Empodisma minus. 

Surface level changes exhibited surprisingly hysteretic behaviour subsequent to raised AWLs, when the rise of ASL was delayed. This delay reversed the positive ASL-AWL relationship because the surface slowly rose even though AWL started receding. Hysteresis was more pronounced during the dry season than during the wet season. The observed hysteresis can be sufficiently simulated by a simplistic model incorporating delayed ASL fluctuations. 

PSO has wide implications for peatland hydrology by reducing RWL fluctuations, which feed back to peat decomposition and plant cover and potentially to (drainable) porosity. Stable RWL also reduce the probability of surface run-off. It is further argued that the gas content of the roots of plants, particularly Empodisma minus, added enough buoyancy to detach the uppermost peat layers resulting in flotation.

year: 2006

title: Inclusive education for children with disabilities in Fiji: Teacher perspectives and attitudes

authors: Daveta, Mereoni Laveti

subjects: inclusive education

abstract: The purpose of this research was to examine teacher perspectives and
attitudes on inclusive education for children with disabilities in Fiji. Teachers'
perspectives and attitudes are crucial in providing insights that could
help improve education and services for children with disabilities in regular
schools in Fiji.
A qualitative approach using semi structured interviews was selected as
the methodology for this research. Nine teachers from nine different
schools in Suva, the capital city of Fiji, participated in this research. The
nine participants were selected from three different school settings. Three
of the participants were from special schools, three were from primary
schools and three were from secondary schools.
Data collected showed that teachers support inclusive education, however,
they had reservations on the inclusion of students with severe disabilities.
Several factors were identified to influence teachers' attitudes towards inclusion.
The most common factors were severity of disability that the students
had, inadequate training of teachers on teaching students with disabilities,
inadequate government funding, lack of specialised resource personnel
and lack of appropriate equipment and resources to support students
and teachers in the teaching learning process. Limited commitment
from the Ministry of Education and limited participation and consultation of
teachers on policy and curriculum design were also identified as contributing
factors for non inclusion of students with disabilities in regular schools.
Teachers need to change their perspectives and attitudes and schools
need to be welcoming and prepared to accept all students with disabilities
into the general education system in Fiji.

text: Inclusive education for children with disabilities in Fiji: Teacher perspectives and attitudes The purpose of this research was to examine teacher perspectives and
attitudes on inclusive education for children with disabilities in Fiji. Teachers'
perspectives and attitudes are crucial in providing insights that could
help improve education and services for children with disabilities in regular
schools in Fiji.
A qualitative approach using semi structured interviews was selected as
the methodology for this research. Nine teachers from nine different
schools in Suva, the capital city of Fiji, participated in this research. The
nine participants were selected from three different school settings. Three
of the participants were from special schools, three were from primary
schools and three were from secondary schools.
Data collected showed that teachers support inclusive education, however,
they had reservations on the inclusion of students with severe disabilities.
Several factors were identified to influence teachers' attitudes towards inclusion.
The most common factors were severity of disability that the students
had, inadequate training of teachers on teaching students with disabilities,
inadequate government funding, lack of specialised resource personnel
and lack of appropriate equipment and resources to support students
and teachers in the teaching learning process. Limited commitment
from the Ministry of Education and limited participation and consultation of
teachers on policy and curriculum design were also identified as contributing
factors for non inclusion of students with disabilities in regular schools.
Teachers need to change their perspectives and attitudes and schools
need to be welcoming and prepared to accept all students with disabilities
into the general education system in Fiji.

year: 2009

title: The intergenerational perpetuation of achievement messages in whānau

authors: Southey, Kim Marie

subjects: Maori

abstract: The current research is an open exploration of achievement messages that are carried from generation to generation in whānau, in relation to the mainstream education system of Aotearoa. Participant groups comprised of two to three generations within each whānau. A maximum of eight whānau will be asked to participate. A series of continuous conversations will be held with each member of the whānau, reminiscent of the narrative approach, but most recently described as a methodology that allows for ensuring that data is collected in its fullest form.
Differing views about achievement and how it is negotiated within whānau will be explored; along with issues on what, and who, within whānau are the most predominant indicators of achievement views. Detracting from an ethnocentric view of scholastic ability (a common marker for achievement) is done through abandoning mainstream ideals. This research favours an open exploration approach allowing for differing values about what constitutes achievement, and what context achievement is based in. Outcomes of the research are intended to show patterns within whānau and among Māori on the mainstream school system, and how this system has contributed to achievement messages. The positive or negative nature of the contribution from mainstream education is highly important and relevant to further research goals, including the ability to use outcomes to suggest social change in education provision for Māori.

text: The intergenerational perpetuation of achievement messages in whānau The current research is an open exploration of achievement messages that are carried from generation to generation in whānau, in relation to the mainstream education system of Aotearoa. Participant groups comprised of two to three generations within each whānau. A maximum of eight whānau will be asked to participate. A series of continuous conversations will be held with each member of the whānau, reminiscent of the narrative approach, but most recently described as a methodology that allows for ensuring that data is collected in its fullest form.
Differing views about achievement and how it is negotiated within whānau will be explored; along with issues on what, and who, within whānau are the most predominant indicators of achievement views. Detracting from an ethnocentric view of scholastic ability (a common marker for achievement) is done through abandoning mainstream ideals. This research favours an open exploration approach allowing for differing values about what constitutes achievement, and what context achievement is based in. Outcomes of the research are intended to show patterns within whānau and among Māori on the mainstream school system, and how this system has contributed to achievement messages. The positive or negative nature of the contribution from mainstream education is highly important and relevant to further research goals, including the ability to use outcomes to suggest social change in education provision for Māori.

year: 2003