The O-factor: using the H-factor concept to predict the outcome of organosolv pretreatment

The H-factor, a parameter used extensively to analyze and predict the outcome of kraft pulping, is applied to organosolv pretreatment. The total solid yield after organosolv pretreatment fits well with the H-factor. The concept has been extended to apply to the individual biomass polymers using unique values for the activation energy for the depolymerization of the individual biomass polymers, giving the O-factor concept analogous to the P factor used for analyzing prehydrolysis kinetics. The results showed a linear relationship between ln(L0/L) and O-factor at an activation energy of 96 kJ/mol. The best linear fit for mannan and xylan degradation was obtained at O-factor activation energies of 104 kJ/mol and 142 kJ/mol, respectively, and the formation of furfural and 5-HMF gave a good linear fit using an O-factor activation energy of 150 kJ/mol. The O-factor is thus a useful concept for analyzing organosolv pretreatment when the temperature during pretreatment is not constant.

Deadwood, Soil and Carabid Beetle-Based Interaction Networks—An Initial Case Study from Montane Coniferous Forests in Poland

In four study plots located in silver fir and Scots pine stands in Magura National Park (southeastern Poland), the relationships between the occurrence and biomass of epigeic carabids, the volume of deadwood and soil biochemical properties were investigated. Thirteen carabid beetle species from the genera Abax, Carabus, Molops and Pterostichus were captured. Rare epigeic carabid species in the fauna of Poland and Europe, such as Carabus glabratus (Paykull), Carabus sylvestris (Panzer) and Abax schueppeli (Germar), were recorded. The number of carabid individuals and species captured as well as the mean individual biomass index at different elevations and in forests of different tree compositions differed significantly. There were no correlations between deadwood volume, carabid abundance and the mean individual biomass of the carabid beetles. The mean individual Carabidae biomass increased with elevated pH, soil carbon content, soil dehydrogenase activity and the number of stumps.

MACROALGAS ADERIDAS EM RIZÓFOROS DE Rizophora mangle L. EM BOA VIAGEM-SÃO JOSÉ DE RIBAMAR-MARANHÃO

Esta abordagem teve como objetivo analisar as comunidades de macroalgas aderidas em rizóforos de Rizophora mangle L. na praia de Boa Viagem, São José de Ribamar-Maranhão como parâmetro para compreender melhor os diferentes níveis de variação observados no “Bostrychietum” de diferentes áreas de manguezal nas duas baías que compõem o Golfão Maranhense. Foram traçados 12 transectos de linha de novembro de 2018 a maio de 2019. Foram analisados 108 rizóforos englobados pelos transectos ao longo das coletas. Foram registrados os valores de O2 dissolvido, temperatura da água, pH e salinidade, bem como foram considerados os valores de precipitação disponibilizados por órgão oficial. 17 taxa infragenéricos (06 Chlorophyta e 11 Rhodophyta) foram identificados. Observou-se um crescimento tanto na biomassa total quanto na biomassa das espécies ao longo das coletas. Não foi observado nenhum padrão determinante de distribuição vertical das macroalgas. Os valores de precipitação apresentaram uma correlação positiva com os valores de biomassa algácea total. ABSTRACTThis survey aimed to assess macroalgae community attached to rhizophores of Rizophora. mangle L. in Boa Viagem beach, São José de Ribamar, Maranhão, as a parameter to a better understand of the diff erent levels of variation observed inside “Bostrychietum” from diff erent areas of mangroves in the two bays that integrate Golfão Maranhense. 12 line transects were performed from november/2018 to may/2019. 108 rhizophores selected randomly along the transects were analised. Values of dissolved O๗, water temperature, pH and salinity were registered as well as precipitation levels, provided by offi cial department, were also considered. 17 infrageneric taxa were identifi ed (06 Chlorophyta and 11 Rhodophyta). It has been observed an increase in total biomass, as well as individual biomass species along the time of sampling. Vertical distribution pattern were not observed. Precipitation levels correlated positively to total macroalgae biomass.Keywords: Algae; Mangrove; “Bostrychietum”.

How dense is dense? Toward a harmonized approach to characterizing reefs of non-native Pacific oysters – with consideration of native mussels

Pacific oysters Crassostrea (Magallana) gigas have been successfully invading ecosystems worldwide. As an ecosystem engineer, they have the potential to substantially impact on other species and on functional processes of invaded ecosystems. Engineering strength depends on oyster density in space and time. Density has not yet been studied on the extent of reef structural dynamics. This study assessed abundance of naturalized Pacific oysters by shell length (SL) of live individuals and post-mortem shells at six sites over six consecutive years during post-establishment. Individual biomass, i.e. live wet mass (LWM), flesh mass (FM) and live shell mass (SM LIVE), were determined from a total of 1.935 live oysters in order to estimate areal biomass. The generic term density attribute was used for SL-related population categories and the biomass variables LWM, FM, SM LIVE and SM. As the oyster invasion modulated resident Mytilus edulis beds, the study was supplemented by contemporaneously assessed data of mussels and corresponding analyses. Interrelations of abundance and areal biomass revealed distinct linkages between specific density attributes. Most importantly, large individuals were identified as intrinsic drivers for the determination of areal biomass. Additionally, allometry of large oysters differed from small oysters by attenuated scaling relations. This effect was enhanced by oyster density as results showed that crowding forced large individuals into an increasing slender shape. The significant relationship between the density attributes large oyster and biomass enabled a classification of reef types by large oyster abundance. Reef type (simple or complex reef) and oyster size (small or large) were considered by implementing a novel concept of weighted twin functions (TF) for the relationship between SL and individual biomass. This study demonstrates that the interplay of scaling parameters (scalar, exponent) is highly sensitive to the estimation of individual biomass (shape) and that putative similar scaling parameters can exceedingly affect the estimation of areal biomass. For the first time, this study documents the crucial relevance of areal reference, i.e. cluster density (CD) or reef density (RD), when comparing density. RD considers reef areas devoid of oysters and results from CD reduced by reef coverage (RC) as the relative reef area occupied by oysters. A compilation of density attributes at simple and complex reefs shall serve as a density guide. Irrespective of areal reference, oyster structural density attributes were significantly higher at complex than at simple reefs. In contrast, areal reference was of vital importance when evaluating the impact of engineering strength at ecosystem-level. While mussel CD was similar at both reef types, RD at complex reefs supported significantly more large mussels and higher mussel biomass than at simple reefs. Although mussels dominated both reef types by abundance of large individuals, oysters were the keystone engineers by dominating biomass. The prominent status of large oysters for both allometric scaling and density, presumably characteristic for Pacific oyster populations worldwide, should be considered when conducting future investigations. The effort of monitoring will substantially be reduced as only large oysters have to be counted for an empirical characterization of Pacific oyster reefs. The large oyster concept is independent of sampling season, assessment method or ecosystem, and is also applicable to old data sets. Harmonization on the proposed density attributes with a clear specification of areal reference will allow trans-regional comparisons of Pacific oyster reefs and will facilitate evaluations of engineering strength, reef performance and invasional impacts at ecosystem-level.