title: Contemporary carbon fluxes do not reflect the long-term carbon balance for an Atlantic blanket bog

authors: Ratcliffe, Joshua Lee

subjects: Core scanning

abstract: Peatlands are one of the largest terrestrial stores of carbon. Carbon exchange in peatlands is often assessed solely by measurement of contemporary fluxes; however, these fluxes frequently indicate a much stronger sink strength than that measured by the rate of C accumulation in the peat profile over longer timescales. Here we compare profile-based measurements of C accumulation with the published net ecosystem C balance for the largest peatland area in Britain, the Flow Country of northern Scotland. We estimate the long-term rate of C accumulation to be 15.4 g C m⁻² yr⁻¹ for a site where a recent eddy covariance study has suggested contemporary C uptake more than six times greater (99.37 g C m⁻² yr⁻¹). Our estimate is supported by two further long-term C accumulation records from nearby sites which give comparable results. We demonstrate that a strong contemporary C sink strength may not equate to a strong long-term sink and explore reasons for this disparity. We recommend that contemporary C sequestration should be viewed in the context of the long-term ecological drivers, such as fires, ecohydrological feedbacks and the changing quality of litter inputs.

text: Contemporary carbon fluxes do not reflect the long-term carbon balance for an Atlantic blanket bog Peatlands are one of the largest terrestrial stores of carbon. Carbon exchange in peatlands is often assessed solely by measurement of contemporary fluxes; however, these fluxes frequently indicate a much stronger sink strength than that measured by the rate of C accumulation in the peat profile over longer timescales. Here we compare profile-based measurements of C accumulation with the published net ecosystem C balance for the largest peatland area in Britain, the Flow Country of northern Scotland. We estimate the long-term rate of C accumulation to be 15.4 g C m⁻² yr⁻¹ for a site where a recent eddy covariance study has suggested contemporary C uptake more than six times greater (99.37 g C m⁻² yr⁻¹). Our estimate is supported by two further long-term C accumulation records from nearby sites which give comparable results. We demonstrate that a strong contemporary C sink strength may not equate to a strong long-term sink and explore reasons for this disparity. We recommend that contemporary C sequestration should be viewed in the context of the long-term ecological drivers, such as fires, ecohydrological feedbacks and the changing quality of litter inputs.

year: 2017

title: Isolation and X-ray structure of the platinum(II)–amidate complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂], an intermediate in the silver(I) oxide-mediated synthesis of a platinalactam complex

authors: Henderson, William

subjects: Metallacycle complexes

abstract: The reaction of cis-[PtCl₂(PPh₃)₂] with one equivalent of N-cyanoacetylurethane, EtO₂CNHC(O)CH₂CN and silver(I) oxide, in dichloromethane at room temperature for short reaction times gives the complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂] in high yield. This complex is an intermediate to the previously reported platinalactam complex [Pt{N(CO₂Et)C(O)CHCN}(PPh₃)₂]. The new complex was characterised by multinuclear NMR spectroscopy, electrospray mass spectrometry, and a single-crystal X-ray study. The deprotonated cyanoacetylurethane ligand lies in a plane almost perpendicular to the platinum coordination plane. Other metal oxides were studied in place of silver(I) oxide for the synthesis of the platinum amidate complex, but none were as successful as silver(I) oxide.

text: Isolation and X-ray structure of the platinum(II)–amidate complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂], an intermediate in the silver(I) oxide-mediated synthesis of a platinalactam complex The reaction of cis-[PtCl₂(PPh₃)₂] with one equivalent of N-cyanoacetylurethane, EtO₂CNHC(O)CH₂CN and silver(I) oxide, in dichloromethane at room temperature for short reaction times gives the complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂] in high yield. This complex is an intermediate to the previously reported platinalactam complex [Pt{N(CO₂Et)C(O)CHCN}(PPh₃)₂]. The new complex was characterised by multinuclear NMR spectroscopy, electrospray mass spectrometry, and a single-crystal X-ray study. The deprotonated cyanoacetylurethane ligand lies in a plane almost perpendicular to the platinum coordination plane. Other metal oxides were studied in place of silver(I) oxide for the synthesis of the platinum amidate complex, but none were as successful as silver(I) oxide.

year: 2000-01-01

title: Looking at relationships between propositions in Maori language

authors: Houia, Waldo

subjects: Te reo Māori

abstract: This paper reports on an investigation into the various ways in which relationships of meaning, such as reason-result and temporal overlap, are encoded as clauses, sentences and groups of sentences in Māori. It also provides an indication of the relevance of this type of research to teachers and learners of Māori.

text: Looking at relationships between propositions in Maori language This paper reports on an investigation into the various ways in which relationships of meaning, such as reason-result and temporal overlap, are encoded as clauses, sentences and groups of sentences in Māori. It also provides an indication of the relevance of this type of research to teachers and learners of Māori.

year: 2001