Forest History as a Basis for Ecosystem Restoration—A Multidisciplinary Case Study in a South Swedish Temperate Landscape

Basic knowledge of the previous forest types or ecosystem present in an area ought to be an essential part of all landscape restoration. Here, we present a detailed study of forest and land use history over the past 2,000 years, from a large estate in southernmost Sweden, which is currently undergoing a restoration program. In particular, the aim was to identify areas with long continuity of important tree species and open woodland conditions. We employed a multidisciplinary approach using paleoecological analyses (regional and local pollen, plant macrofossil, tree ring) and historical sources (taxation documents, land surveys, forest inventories). The estate has been dominated by temperate broad‐leaved trees over most of the studied period. When a forest type of Tilia, Corylus, and Quercus started to decline circa 1,000 years ago, it was largely replaced by Fagus. Even though extensive planting of Picea started in mid‐nineteenth century, Fagus and Quercus have remained rather common on the estate up to present time. Both species show continuity on different parts of the estate from eighteenth century up to present time, but in some stands, for the entire 2,000 years. Our suggestions for restoration do not aim for previous “natural” conditions but to maintain the spatial vegetational pattern created by the historical land use. This study gives an example of the spatial and temporal variation of the vegetation that has historically occurred within one area and emphasizes that information from one methodological technique provides only limited information about an area’s vegetation history.     

Cultivation, photobioreactor design and harvesting of microalgae for biodiesel production: A critical review

Microalgae have the ability to mitigate CO₂ emission and produce oil with a high productivity, thereby having the potential for applications in producing the third-generation of biofuels. The key technologies for producing microalgal biofuels include identification of preferable culture conditions for high oil productivity, development of effective and economical microalgae cultivation systems, as well as separation and harvesting of microalgal biomass and oil. This review presents recent advances in microalgal cultivation, photobioreactor design, and harvesting technologies with a focus on microalgal oil (mainly triglycerides) production. The effects of different microalgal metabolisms (i.e., phototrophic, heterotrophic, mixotrophic, and photoheterotrophic growth), cultivation systems (emphasizing the effect of light sources), and biomass harvesting methods (chemical/physical methods) on microalgal biomass and oil production are compared and critically discussed. This review aims to provide useful information to help future development of efficient and commercially viable technology for microalgae-based biodiesel production.     

Effect of different carbon sources on cellulase production by Hypocrea jecorina (Trichoderma reesei) strains

The ascomycete Hypocrea jecorina, an industrial (hemi)cellulase producer, can efficiently degrade plant polysaccharides. At present, the biology underlying cellulase hyperproduction of T. reesei, and the conditions for the enzyme induction, are not completely understood. In the current study, three different strains of T. reesei, including QM6a (wild-type), and mutants QM9414 and RUT-C30, were grown on 7 soluble and 7 insoluble carbon sources, with the later group including 4 pure polysaccharides and 3 lignocelluloses. Time course experiments showed that maximum cellulase activity of QM6a and QM9414 strains, for the majority of tested carbon sources, occurred at 120 hrs, while RUT-C30 had the greatest cellulase activity around 72 hrs. Maximum cellulase production was observed to be 0.035, 0.42 and 0.33 µmol glucose equivalents using microcrystalline celluloses for QM6a, QM9414, and RUTC-30, respectively. Increased cellulase production was positively correlated in QM9414 and negatively correlated in RUT-C30 with ability to grow on microcrystalline cellulose.     

Carbon and nitrogen sources influence the ligninolytic enzyme activity of <Emphasis Type="Italic">Trametes versicolor</Emphasis>

Among carbon sources studied, cellobiose and mannitol provided the highest laccase (Lac) activity (648 and 742 U1^-1, respectively) of Trametes versicolor 775 while glucose gave maximum manganese peroxidase (MnP) and peroxidase activities (44 and 114U1^-1, respectively). Citrus fruit peel as growth substrate enhanced Lac activity 7-fold when compared to the medium with cellobiose, whereas grape vine sawdust increased MnP and peroxidase activity up to 148 and 677U1^-1, respectively.     

Nectar and Pollen Sources for Honeybee （Apis cerana cerana Fabr.） in Qinglan Mangrove Area, Hainan Island, China

In the present study, nectar and pollen sources for honeybee （Apls cerana cerana Fabr.） were studied in Qlnglan mangrove area, Hainan Island, China, based on microscopic analysis of honey and pollen load （corblcular and gut contents） from honeybees collected In October and November 2004. Qualitative and quantitative melittopalynologlcal analysis of the natural honey sample showed that the honey is of unlfloral type with Mimosa pudlca L. （Mlmosaceae） as the predominant （89.14%） source of nectar and pollen for A. cerana cerana In October. Members of Araceae are an Important minor （3%-15%） pollen type, whereas those of Arecaceae are a minor （〈3%） pollen type. Pollen grains of Nypa fruticans Wurmb., Rhlzophora spp., Excoecarla agallocha L., Lumnitzera spp., Brugulera spp., Kandella candel Druce, and Ceriops tagal （Perr.） C. B. Rob. are among the notable mangrove texa growing In Qinglan mangrove area recorded as minor taxa In the honey. The absolute pollen count （I.e. the number of pollen grains/10 g honey sample） suggests that the honey belongs to Group V （〉1 000 000）. Pollen analysis from the corblcular and gut contents of A. cerana cerana revealed the highest representation （95.60%） of members of Sonneratia spp. （Sonneratlaceae）, followed by Bruguiera spp. （Rhizophoraceae）, Euphorblaceae, Poaceae, Fabaceae, Arecaceae, Araceae, Anacardlaceae, and Rublaceae. Of these plants, those belonging to Sonneratla plants are the most Important nectar and pollen sources for A. cerana cerana and are frequently foraged and pollinated by these bees in November.     

Factors Influencing Formation of Sclerotia in Grifola umbellate （Pers.） Pilaet Under Artificial Conditions

The effects of substrate composition and temperature on myceilal growth and sclerotium production in Grlfola umbellate （Pers.） Pilaet were Investigated In the present study. The Induction of sclerotla of G. umbellate was affected greatly by the type of medium, as well as the type of carbon source. Malt-extract agar was able to induce the production of sclerotia. The production of sclerotia was also observed when the carbon source in the GPC agar medium （glucose 20 g/L, peptone 6 g/L, corn steep liquor 10 g/L, and agar 15 g/L） was replaced with glycerol or mannitol. Altering the composition of the GPC medium with milk powder, thiamine hydrochlorlde, extract of Armlllarla mellea, active clay, dlatomite, kaolin, or arginlne did not induce the production of sclerotla. A temperature range of 18-25 ℃ was suitable for both mycellai growth and sclerotium formation. Glycerol significantly Induced slerotium formation on nutrient supplemented with sawdust substrates In bottle culture. 24S-Polyporusterone A and polyporusterone B were assayed In samples of natural and cultured sclerotla. Both natural and cultured sclerotla contained 24S- polyporusterone A and polyporusterone B.     

Avian foraging studies: an overlooked source of distribution data for macroecological and conservation studies

Macroecological and biogeographical studies and their applicability for biological conservation vitally depend on distribution data. These are usually taken from distribution atlases and databases or maps found in identification guides. A previous study pointed to another little explored source of data — local faunistic studies. Here, I would like to draw attention to another potential source. Papers that analysed the food composition of some taxa (e.g. insectivorous birds) are an overlooked source of rich information on taxa distributions. These studies frequently include an 'Appendix' with a list of food items determined to the species level. These studies also contain data on abundances, number of samples, sampling time, and geographical location as a rule. Foraging birds naturally provide data on invertebrate distributions with good spatio-temporal coverage and reasonably large samples. Importantly, birds frequently collect rare and by entomological methods hardly detectable species (i.e. those living high, in tree canopies, in very dense vegetation, or with secretive lifestyle). Data from bird dietary studies may help to ameliorate one of the most serious problems in distribution studies — zero inflation. I briefly discuss pros and cons of this so far neglected source of biogeographical data.     

Eutrophication in Australian Rivers, Reservoirs and Estuaries – A Southern Hemisphere Perspective on the Science and its Implications

Australian science has made rapid advances in the last decade in understanding eutrophication processes in inland waters and estuaries. The freshwater research on which these advances are based was triggered by well-publicised blooms of cyanobacteria during the 1980s and early 1990s, particularly a 1000 km long bloom on the Darling River. In estuaries the study which greatly enhanced our understanding but simultaneously served to stimulate further research into estuarine eutrophication, the Port Phillip Bay Study, was initially designed to address perceived problems of toxicants in the Bay but provided profound insights into drivers for, and ecosystem responses to, eutrophication. Subsequent estuarine research has largely been stimulated by management questions arising from Australia’s increasing coastal development for residential purposes. The research has shown that some of the beliefs extant at the time of the blooms were incorrect. For example, it is now clear that stratification and light penetration, not nutrient availability, are the triggers for blooms in the impounded rivers of southeastern Australia, although nutrient exhaustion limits the biomass of blooms. Again, nitrogen seems to play as important a role as phosphorus does in controlling the biomass of these freshwater blooms. The research has also shown that aspects of eutrophication, such as nutrient transport, are dominated by different processes in different parts of Australia. Many of the biophysical processes involved in eutrophication have now been quantified sufficiently for models to be developed of such processes as sediment-nutrient release, stratification, turbidity and algal growth in both freshwater and estuarine systems. In some cases the models are reliable enough for the knowledge gained in particular waterbodies to be applied elsewhere. Thus, there is now a firm scientific foundation for managers to rely upon when managing algal blooms. Whilst these findings have already been presented to managers and communities throughout Australia, there is still a considerable way to go before they are absorbed into their modus operandi.     

HOW MANY SPECIES OF ALGAE ARE THERE?

Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on‐line taxonomic database AlgaeBase ( http://www.algaebase.org ). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species, names for 44,000 of which have probably been published, and 33,248 names have been processed by AlgaeBase to date (June 2012). Some published estimates of diatom numbers are of over 200,000 species, which would result in four to five diatom species for every other algal species. Concern is expressed at the decline and potential extinction of taxonomists worldwide capable of improving and completing the necessary systematic studies.     

Crystallography with online optical and X-ray absorption spectroscopies demonstrates an ordered mechanism in copper nitrite reductase

Nitrite reductases are key enzymes that perform the first committed step in the denitrification process and reduce nitrite to nitric oxide. In copper nitrite reductases, an electron is delivered from the type 1 copper (T1Cu) centre to the type 2 copper (T2Cu) centre where catalysis occurs. Despite significant structural and mechanistic studies, it remains controversial whether the substrates, nitrite, electron and proton are utilised in an ordered or random manner. We have used crystallography, together with online X-ray absorption spectroscopy and optical spectroscopy, to show that X-rays rapidly and selectively photoreduce the T1Cu centre, but that the T2Cu centre does not photoreduce directly over a typical crystallographic data collection time. Furthermore, internal electron transfer between the T1Cu and T2Cu centres does not occur, and the T2Cu centre remains oxidised. These data unambiguously demonstrate an ‘ordered’ mechanism in which electron transfer is gated by binding of nitrite to the T2Cu. Furthermore, the use of online multiple spectroscopic techniques shows their value in assessing radiation-induced redox changes at different metal sites and demonstrates the importance of ensuring the correct status of redox centres in a crystal structure determination. Here, optical spectroscopy has shown a very high sensitivity for detecting the change in T1Cu redox state, while X-ray absorption spectroscopy has reported on the redox status of the T2Cu site, as this centre has no detectable optical absorption.