title: Effect of sapstaining fungi on structural wood integrity of radiata pine (Pinus radiata D. Don)

authors: Schirp, Anke

abstract: Selected sapstaining fungi belonging to the Ascomycetes and Fungi Imperfecti isolated in New Zealand were evaluated for potential degradation of unseasoned radiata pine sapwood using four independent methods: i) toughness and weight loss measurements, ii) chemical analysis of wood composition, iii) enzyme assays and iv) light and scanning electron microscopy. Several isolates of albino-strains, potential candidates for use as biocontrol agents against sapstain on radiata pine, were included in the experiments.

Sets of side-matched specimens were inoculated with isolates of Ophiostoma floccosum, O. pluriannulatum, O. ips, O. piceae, Leptographium procerum and Sphaeropsis sapinea and incubated for 8 or 16 weeks, along with non-inoculated control samples. Three decay fungi, Gloeophyllum trabeum, Phlebiopsis gigantea and Schizophyllum commune, were included in the tests to serve as references for weight and toughness loss. After incubation, the samples were equilibrated to 14% moisture content before recording toughness and weight losses. Weight loss was determined by comparing the dry weights of the inoculated samples to the untreated controls rather than expressing weight loss as a percentage of the original weight of a sample.

Neither toughness nor dry weight were significantly (p<0.05) different between specimens inoculated with sapstaining fungi and their controls, except for an isolate of O. ips in one out of three experiments. This isolate of O. ips caused 18% toughness loss without causing weight loss. In one out of four experiments, there was a slight, but statistically significant (p < 0.05) overall weight loss of samples inoculated with different sapstaining isolates which was attributed to the degradation of non-lignified parenchyma cells and extractives. In comparison, the brown-rot fungus G. trabeum caused up to 61% toughness loss after 4 months’ incubation, accompanied by a weight loss of 8%, and the white-rot fungus S. commune produced a toughness loss of 32% without any significant weight loss which indicates that toughness loss is a more sensitive indicator of decay than weight loss.

None of the sapstaining fungi tested caused significant reductions of lignin or structural carbohydrates (arabinose, galactose, glucose, xylose and mannose) in radiata pine sapwood after 16 weeks’ incubation, but all fungal strains, with the exception of O. pluriannulatum, reduced the amount of extractives significantly. Of the isolates tested, O. floccosum degraded extractives most effectively (53.6% reduction). The fact that there were no major differences with regard to the composition of the structural cell wall components of sapstained wood and controls complements the results obtained in the weight loss experiments. Significant amylose and extractives consumption reflect the observation of sapstaining fungi growing extensively in the parenchyma cells and resin canals of radiata pine.

Sapstaining fungi secrete hydrolytic enzymes into the growth substrate and subsequently absorb the products of hydrolysis in the fungal mycelium. Enzyme assays demonstrated that all sapstaining isolates tested secreted low amounts of xylanase (up to 1.64 μmoles/min/ml) and pectinase (up to 0.11 μmoles/min/ml) into the growth medium, but extracellular cellulose was not detected. Under the conditions tested, mannanase was secreted only by O. piceae (0.29 μmole/min/ml). The results suggest that although galactoglucomannans are the major hemicelluloses in softwoods, the arabino-4-methylglucuronoxylans are preferably used by sapstaining as well as decay fungi when growing in softwoods. This may be attributed to the accessibility of the xylans in the S₃-layer of the wood cell wall. Amylase activity of the fungal species tested was more significant than xylanase, mannanase and pectinase activities which confirms that sapstaining fungi preferably metabolize easily accessible, non-structural wood components like starch.

A possible function of the cell-wall degrading enzymes may be the facilitation of the colonization of wood cells, specifically, pectinase may assist the fungal penetration of pit membranes. It is likely that the extracellular sheath which has been observed around hyphae of S. sapinea contains these enzymes and represents an important source of support and hyphal contact with the host cell wall. In addition, pectinase and xylanase could be involved in the pathogenesis of certain sapstaining fungi, as has been demonstrated for O. ulmi and O. novoulmi. The production of specific antibodies against xylanase and pectinase and the subsequent immunohistochemical localization in the host might resolve this question.

Hyphae of sapstaining fungi pass from one wood cell to another by growing through the pit membranes. No differences were observed with regard to the spatial distribution of the sapstaining fungi. Direct cell wall penetration was not observed. The non-lignified parenchyma cell walls of the wood samples infected with sapstaining fungi appeared to be degraded. The ray tracheids in radiata pine were less colonized than the parenchyma cells. 

Although low amounts of hemicellulolytic enzymes and pectinase were detected, the effect of sapstaining fungi on wood quality of radiata pine has to be considered cosmetic and non-degradative which confirms the evaluation of sapstain according to the New Zealand Timber Grading Rules (NZS 3631, 1988). In general, sapstaining fungi do not affect the structural wood integrity of radiata pine. If severe sapstain occurs which obscures the grain, there is a possibility that decay fungi may also be present, and since decay fungi do affect the strength of timber, it seems justified not to allow for the use of severely sapstained timber for structural purposes, consistent with NZS 3631 (1988). The use of selected albino-strains of the naturally occurring sapstain population in New Zealand as biocontrol agents on radiata pine logs and timber can be recommended since these fungi were also not found to decrease toughness nor to cause weight loss in radiata pine.

text: Effect of sapstaining fungi on structural wood integrity of radiata pine (Pinus radiata D. Don) Selected sapstaining fungi belonging to the Ascomycetes and Fungi Imperfecti isolated in New Zealand were evaluated for potential degradation of unseasoned radiata pine sapwood using four independent methods: i) toughness and weight loss measurements, ii) chemical analysis of wood composition, iii) enzyme assays and iv) light and scanning electron microscopy. Several isolates of albino-strains, potential candidates for use as biocontrol agents against sapstain on radiata pine, were included in the experiments.

Sets of side-matched specimens were inoculated with isolates of Ophiostoma floccosum, O. pluriannulatum, O. ips, O. piceae, Leptographium procerum and Sphaeropsis sapinea and incubated for 8 or 16 weeks, along with non-inoculated control samples. Three decay fungi, Gloeophyllum trabeum, Phlebiopsis gigantea and Schizophyllum commune, were included in the tests to serve as references for weight and toughness loss. After incubation, the samples were equilibrated to 14% moisture content before recording toughness and weight losses. Weight loss was determined by comparing the dry weights of the inoculated samples to the untreated controls rather than expressing weight loss as a percentage of the original weight of a sample.

Neither toughness nor dry weight were significantly (p<0.05) different between specimens inoculated with sapstaining fungi and their controls, except for an isolate of O. ips in one out of three experiments. This isolate of O. ips caused 18% toughness loss without causing weight loss. In one out of four experiments, there was a slight, but statistically significant (p < 0.05) overall weight loss of samples inoculated with different sapstaining isolates which was attributed to the degradation of non-lignified parenchyma cells and extractives. In comparison, the brown-rot fungus G. trabeum caused up to 61% toughness loss after 4 months’ incubation, accompanied by a weight loss of 8%, and the white-rot fungus S. commune produced a toughness loss of 32% without any significant weight loss which indicates that toughness loss is a more sensitive indicator of decay than weight loss.

None of the sapstaining fungi tested caused significant reductions of lignin or structural carbohydrates (arabinose, galactose, glucose, xylose and mannose) in radiata pine sapwood after 16 weeks’ incubation, but all fungal strains, with the exception of O. pluriannulatum, reduced the amount of extractives significantly. Of the isolates tested, O. floccosum degraded extractives most effectively (53.6% reduction). The fact that there were no major differences with regard to the composition of the structural cell wall components of sapstained wood and controls complements the results obtained in the weight loss experiments. Significant amylose and extractives consumption reflect the observation of sapstaining fungi growing extensively in the parenchyma cells and resin canals of radiata pine.

Sapstaining fungi secrete hydrolytic enzymes into the growth substrate and subsequently absorb the products of hydrolysis in the fungal mycelium. Enzyme assays demonstrated that all sapstaining isolates tested secreted low amounts of xylanase (up to 1.64 μmoles/min/ml) and pectinase (up to 0.11 μmoles/min/ml) into the growth medium, but extracellular cellulose was not detected. Under the conditions tested, mannanase was secreted only by O. piceae (0.29 μmole/min/ml). The results suggest that although galactoglucomannans are the major hemicelluloses in softwoods, the arabino-4-methylglucuronoxylans are preferably used by sapstaining as well as decay fungi when growing in softwoods. This may be attributed to the accessibility of the xylans in the S₃-layer of the wood cell wall. Amylase activity of the fungal species tested was more significant than xylanase, mannanase and pectinase activities which confirms that sapstaining fungi preferably metabolize easily accessible, non-structural wood components like starch.

A possible function of the cell-wall degrading enzymes may be the facilitation of the colonization of wood cells, specifically, pectinase may assist the fungal penetration of pit membranes. It is likely that the extracellular sheath which has been observed around hyphae of S. sapinea contains these enzymes and represents an important source of support and hyphal contact with the host cell wall. In addition, pectinase and xylanase could be involved in the pathogenesis of certain sapstaining fungi, as has been demonstrated for O. ulmi and O. novoulmi. The production of specific antibodies against xylanase and pectinase and the subsequent immunohistochemical localization in the host might resolve this question.

Hyphae of sapstaining fungi pass from one wood cell to another by growing through the pit membranes. No differences were observed with regard to the spatial distribution of the sapstaining fungi. Direct cell wall penetration was not observed. The non-lignified parenchyma cell walls of the wood samples infected with sapstaining fungi appeared to be degraded. The ray tracheids in radiata pine were less colonized than the parenchyma cells. 

Although low amounts of hemicellulolytic enzymes and pectinase were detected, the effect of sapstaining fungi on wood quality of radiata pine has to be considered cosmetic and non-degradative which confirms the evaluation of sapstain according to the New Zealand Timber Grading Rules (NZS 3631, 1988). In general, sapstaining fungi do not affect the structural wood integrity of radiata pine. If severe sapstain occurs which obscures the grain, there is a possibility that decay fungi may also be present, and since decay fungi do affect the strength of timber, it seems justified not to allow for the use of severely sapstained timber for structural purposes, consistent with NZS 3631 (1988). The use of selected albino-strains of the naturally occurring sapstain population in New Zealand as biocontrol agents on radiata pine logs and timber can be recommended since these fungi were also not found to decrease toughness nor to cause weight loss in radiata pine.

year: 2001

title: Intellectual Capital Reporting by the New Zealand Local Government Sector

authors: Schneider, Annika Barbara Sabine

subjects: intellectual capital

abstract: Sweeping financial management reforms occurred in New Zealand during the late 1980s and early 1990s which radically changed the face of the New Zealand public sector.  These reforms sought to significantly restructure and reorganise local government thereby improving their effectiveness and efficiency and improving their accountability to their stakeholders. The principal vehicle for the discharge of this accountability is the annual report, which must be prepared according to Generally Accepted Accounting Practice (GAAP) and commercial principles.

Organisations in the private sector are beginning to recognise the value of accounting for intellectual capital (IC) (see for example Quinn, 1992; Brooking, 1996; Sveiby, 1997; Edvinsson  Malone, 1997; Bontis, Dragonetti, Jacobsen  Roos, 1999; Guthrie, Petty  Johanson, 2001; Bounfour, 2003). Studies on the measurement, management and reporting of IC have been undertaken internationally in Asia (Abeysekera  Guthrie, 2005; Goh  Lim, 2004; Ordenez de Pablos, 2002), Australia (Guthrie  Petty, 2000), Europe (Bozzolan, Favotto and Ricceri, 2003; Olsson, 2001; Ordenez de Pablos, 2004), United Kingdom (Collier, 2001; Williams, 2001) and Ireland (Brennan, 2001).
 
Despite the significant research interest in the field of intellectual capital internationally, scant attention has been paid to intellectual capital reporting by commercial organisations in New Zealand. An extensive review of the IC literature yielded only two New Zealand based studies (Miller  Whiting, 2005; Wong  Gardner, 2005). Further, no studies to date have addressed intellectual capital reporting by local governments in either New Zealand or internationally. This study aims to fill this gap through the development of an intellectual capital disclosure model that could be applied to local authorities.

The research describes and explains the development of a disclosure index used to measure the extent and quality of current intellectual capital disclosure by local authorities in New Zealand. The index was developed through a consultative process with a panel of local government stakeholders which was used to establish the weightings for each item. The final index comprised 26 items divided into three categories: internal capital, external capital and human capital. The 2004/2005 annual reports of 82 New Zealand local authorities were scored for extent and quality of disclosure against the index. 

The results indicate that intellectual capital reporting by local authorities is varied. Manukau City Council scored the achieved the highest overall score (76%) out of the 82 reports analysed while Whakatane District Council scored the lowest with 33%. The most reported items were joint ventures/business collaborations and management processes. The least reported items were intellectual property and licensing agreements. The most reported category of intellectual capital was internal capital, followed by external capital. The least reported category was human capital. The findings indicate a number of areas of reporting that could be improved in order to meet with stakeholder disclosure expectations. In the internal capital category, intellectual property disclosures could be improved. In the external capital category disclosure concerning ratepayer demographics and licensing agreements could be improved. In the human capital category, disclosure of most items could be improved, in particular, entrepreneurial innovativeness and vocational qualifications.

The study provided an insight into the current level and quality of intellectual capital disclosure by the NZ local government sector. The results indicated that local authorities are disclosing some aspects of intellectual capital in their annual report, however there is no consistent reporting framework, and many areas of IC disclosures are not meeting stakeholder expectations. More research is needed in the area of intellectual capital reporting in the public sector. This study provides a preliminary framework which can be used by local authorities to enhance intellectual capital disclosures in their annual reports.

text: Intellectual Capital Reporting by the New Zealand Local Government Sector Sweeping financial management reforms occurred in New Zealand during the late 1980s and early 1990s which radically changed the face of the New Zealand public sector.  These reforms sought to significantly restructure and reorganise local government thereby improving their effectiveness and efficiency and improving their accountability to their stakeholders. The principal vehicle for the discharge of this accountability is the annual report, which must be prepared according to Generally Accepted Accounting Practice (GAAP) and commercial principles.

Organisations in the private sector are beginning to recognise the value of accounting for intellectual capital (IC) (see for example Quinn, 1992; Brooking, 1996; Sveiby, 1997; Edvinsson  Malone, 1997; Bontis, Dragonetti, Jacobsen  Roos, 1999; Guthrie, Petty  Johanson, 2001; Bounfour, 2003). Studies on the measurement, management and reporting of IC have been undertaken internationally in Asia (Abeysekera  Guthrie, 2005; Goh  Lim, 2004; Ordenez de Pablos, 2002), Australia (Guthrie  Petty, 2000), Europe (Bozzolan, Favotto and Ricceri, 2003; Olsson, 2001; Ordenez de Pablos, 2004), United Kingdom (Collier, 2001; Williams, 2001) and Ireland (Brennan, 2001).
 
Despite the significant research interest in the field of intellectual capital internationally, scant attention has been paid to intellectual capital reporting by commercial organisations in New Zealand. An extensive review of the IC literature yielded only two New Zealand based studies (Miller  Whiting, 2005; Wong  Gardner, 2005). Further, no studies to date have addressed intellectual capital reporting by local governments in either New Zealand or internationally. This study aims to fill this gap through the development of an intellectual capital disclosure model that could be applied to local authorities.

The research describes and explains the development of a disclosure index used to measure the extent and quality of current intellectual capital disclosure by local authorities in New Zealand. The index was developed through a consultative process with a panel of local government stakeholders which was used to establish the weightings for each item. The final index comprised 26 items divided into three categories: internal capital, external capital and human capital. The 2004/2005 annual reports of 82 New Zealand local authorities were scored for extent and quality of disclosure against the index. 

The results indicate that intellectual capital reporting by local authorities is varied. Manukau City Council scored the achieved the highest overall score (76%) out of the 82 reports analysed while Whakatane District Council scored the lowest with 33%. The most reported items were joint ventures/business collaborations and management processes. The least reported items were intellectual property and licensing agreements. The most reported category of intellectual capital was internal capital, followed by external capital. The least reported category was human capital. The findings indicate a number of areas of reporting that could be improved in order to meet with stakeholder disclosure expectations. In the internal capital category, intellectual property disclosures could be improved. In the external capital category disclosure concerning ratepayer demographics and licensing agreements could be improved. In the human capital category, disclosure of most items could be improved, in particular, entrepreneurial innovativeness and vocational qualifications.

The study provided an insight into the current level and quality of intellectual capital disclosure by the NZ local government sector. The results indicated that local authorities are disclosing some aspects of intellectual capital in their annual report, however there is no consistent reporting framework, and many areas of IC disclosures are not meeting stakeholder expectations. More research is needed in the area of intellectual capital reporting in the public sector. This study provides a preliminary framework which can be used by local authorities to enhance intellectual capital disclosures in their annual reports.

year: 2006

title: Te tuangi (the clam): A metaphor for teaching, learning and the key competencies

authors: Simpson, Mary Louisa

subjects: Early childhood

abstract: This article explores the shift from “essential skills” to “key competencies” in the school curriculum. Drawing on information gathered from teacher interviews and observations at a New Zealand primary school, this article suggests that culture and context strongly shape and influence the interpretation of key competencies. The authors develop a metaphor—te tuangi—to theorise the relationship between a learner (akonga) and a teacher (kaiako) in a cultural and social context.

text: Te tuangi (the clam): A metaphor for teaching, learning and the key competencies This article explores the shift from “essential skills” to “key competencies” in the school curriculum. Drawing on information gathered from teacher interviews and observations at a New Zealand primary school, this article suggests that culture and context strongly shape and influence the interpretation of key competencies. The authors develop a metaphor—te tuangi—to theorise the relationship between a learner (akonga) and a teacher (kaiako) in a cultural and social context.

year: 2011