The Semiglades: The Collision of Restoration,Social Values,and the Ecosystem Concept

Defining success targets in restoration and how social values affect them are two commonly discussed issues in restoration today. We believe that how success is commonly defined—with vague terms such as “healthy ecosystem” or cited as a return to a previous, historic state—needs to be reevaluated. With the increasing number of novel ecosystems, there is an increasing conflict between the ecosystem concept, social values, and restoration. This arises from the fact that ecosystems are defined by the values of the scientists describing them, necessarily constraining the ecosystem to a generally static concept. It is not directly the concept, but how it is perceived through our filter of social values that represses the creativity and innovation needed in restoration today. Within restoration, we feel that the ecosystem concept does a disservice by ignoring the increasing number of novel systems, and that hinders real progress in a time when hesitation can be costly. To best illustrate this, we offer the example of restoration of the Florida Everglades and how it has become a novel system in pattern and process. We suggest renaming the Everglades “The Semiglades” in hopes of opening a dialog to expose social/ecosystem biases and include novel landscapes in management and planning.     

Differences in trait compositions between rocky natural and artificial habitats

Question: What are the differences in trait compositions that enable native plants to colonise comparable natural and man‐made habitats? Are these traits independent of phylogenetic relationships between species? Location: Czech Republic. Methods: The relative importance of biological, ecological and distributional traits of native species was studied, using a dataset of 75 species growing in rock and wall habitats in the Czech Republic. Species preferences for individual habitats due to climatic conditions and proportions of different vegetation types in their surroundings were partialled out using partial canonical correspondence analysis. The pattern of plant traits along a gradient from natural rock habitats to secondary wall habitats was analysed using regression trees and generalized linear models with and without phylogenetic correction. Results: The most common native species colonising rock habitats are phanerophytes, mostly woody juveniles, with a CSR life strategy and most are adapted to epizoochory. Summer green leaves, annual life span, CR life strategy, reproduction mostly by seeds and dispersal by ants are all traits positively associated with the ability of species to colonise wall habitats. These species are also characterised by their high demand for nutrients, temperature, base‐rich substrates and light. Biological and ecological traits are more important for colonising new habitats than traits related to species dispersal ability or phylogenetic relationships between species. Biological and ecological traits alone explained 29.3% of variability in the species dataset, while dispersal characteristics and phylogeny alone explained 9.1% and 4.8%, respectively. Conclusions: We outline how the process of environmental filtering determines native species assemblages and identify a set of species traits that enable them to persist in particular habitats. We conclude that although urbanisation generally results in loss of natural habitats, there are new, man‐made habitats potentially suitable for native species.     

Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: critical issues and global evaluation

The measured net ecosystem exchange (NEE) of CO₂ between the ecosystem and the atmosphere reflects the balance between gross CO₂ assimilation [gross primary production (GPP)] and ecosystem respiration (R_eco). For understanding the mechanistic responses of ecosystem processes to environmental change it is important to separate these two flux components. Two approaches are conventionally used: (1) respiration measurements made at night are extrapolated to the daytime or (2) light–response curves are fit to daytime NEE measurements and respiration is estimated from the intercept of the ordinate, which avoids the use of potentially problematic nighttime data. We demonstrate that this approach is subject to biases if the effect of vapor pressure deficit (VPD) modifying the light response is not included. We introduce an algorithm for NEE partitioning that uses a hyperbolic light response curve fit to daytime NEE, modified to account for the temperature sensitivity of respiration and the VPD limitation of photosynthesis. Including the VPD dependency strongly improved the model's ability to reproduce the asymmetric diurnal cycle during periods with high VPD, and enhances the reliability of R_eco estimates given that the reduction of GPP by VPD may be otherwise incorrectly attributed to higher R_eco. Results from this improved algorithm are compared against estimates based on the conventional nighttime approach. The comparison demonstrates that the uncertainty arising from systematic errors dominates the overall uncertainty of annual sums (median absolute deviation of GPP: 47 g C m^?2 yr^?1), while errors arising from the random error (median absolute deviation: ～2 g C m^?2 yr^?1) are negligible. Despite site‐specific differences between the methods, overall patterns remain robust, adding confidence to statistical studies based on the FLUXNET database. In particular, we show that the strong correlation between GPP and R_eco is not spurious but holds true when quasi‐independent, i.e. daytime and nighttime based estimates are compared.     

Calculating pKa values in the cAMP-dependent protein kinase: the effect of conformational change and ligand binding

The conformational change observed upon ligand binding and phosphorylation for the cAMP-dependent protein kinase (protein kinase A-PKA) is of high importance for the regulation of its activity. We calculate pKa values and net charges for 18 3D structures of PKA in various conformations and liganded states to examine the role of electrostatics in ligand binding and activation. We find that the conformational change of PKA takes place without any significant net proton uptake/release at all pH values, thus indicating that PKA has evolved to reduce any pH-dependent barriers to the conformational motion. We furthermore find that the binding of ligands induces large changes in the net charge of PKA at most pH values, but significantly, we find that the net charge difference at physiological pH is close to zero, thus indicating that the active-site pKa values have been preorganized for substrate binding. We are unable to unequivocally resolve the identity of the groups responsible for determining the pH-activity profile of PKA but speculate that the titration of Lys 168 or the titration of ATP itself could be responsible for the loss of activity at high pH values. Finally, we examine the effect of point mutations on the pKa values of the PKA catalytic residues and find these to be relatively insensitive to both noncharge-altering and charge-altering mutations.     

Woody plants and the prediction of climate-change impacts on bird diversity

Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climate change. Forecasts assuming an instantaneous response of woody plants and birds to climate change suggested increases in future bird species richness across most of Kenya whereas forecasts assuming strongly lagged woody plant responses to climate change indicated a reversed trend, i.e. reduced bird species richness. Uncertainties in predictions of future bird species richness were geographically structured, mainly owing to uncertainties in projected precipitation changes. We conclude that assessments of future species responses to climate change are very sensitive to current uncertainties in regional climate-change projections, and to the inclusion or not of time-lagged interacting taxa. We expect even stronger effects for more specialized plant–animal associations. Given the slow response time of woody plant distributions to climate change, current estimates of future biodiversity of many animal taxa may be both biased and too optimistic.     

药用植物内生真菌研究现状及其应用前景

随着对药用植物内生真菌研究的深入,从药用植物内生真菌中寻找新的生物活性成分已成为研究热点。内生真菌对药用植物的生长及活性成分的形成都有影响,内生真菌活性成分已成为发现新颖结构化合物及新药物的潜在资源。简要综述了近年来在内生真菌的分离鉴定、发酵、次生代谢产物、与宿主的关系等方面的研究进展。     

23436例不同性别坐、卧位血液流变参考范围的建立

目的:建立健康人群不同性别坐、卧位血液流变参考范围。方法:组织31位志愿者进行坐、卧位配对血液流变检测;用SPSS13.O软件统计分析2002.7年至2006.7年医院数据库32854例血液流变资料,其中健康体检23436例、门诊6553例、住院2865例,以独立样本t检验比较不同体位、性别的差异,建立各自参考范围。结果:坐、卧位总体均数12项指标差异有统计学意义(P<0.01),以坐位为基线,卧位时各切变率、全血粘度、全血还原粘度、血浆粘度及红细胞压积等8项主要指标明显降低,平均降9.33%,而红细胞变形指数、电泳指数则上升,平均升6.49%。与自身坐、卧位配对实验结果一致。男、女性别差异有统计学意义(P<0.01)。结论:体位可引起血液流变各参数显著生理变异,建立不同性别坐、卧位各自参考范围,可提高约8%～10%诊断符合率,减少临床误诊。     

Perturbation experiments and fluctuation enhancement in finite size of lattice ecosystems: Uncertainty in top-predator conservation

Study of perturbation experiments is crucial for conservation biology. We carry out Monte Carlo simulations on finite-size lattices composed of n species (n ≤ 4). The value of mortality rate m of top predator is altered to a higher or lower level, and a fluctuation enhancement (FE) is explored. Here FE means an uncertainty in population dynamics. It is found for n ≥ 2 that FE is observed, when m is decreased. Namely, when we protect the top predator, its population dynamics becomes very difficult to predict.     

Effect of pH on the extraction characteristics of succinic and formic acids with Tri-n-octylamine dissolved in 1-octanol

A study was made on the extraction equilibria of succinic and formic acids from aqueous solutions using tri-n-octylamine (TOA) in 1-octanol. It was shown that the loading values of TOA decreased with increasing pH values. The apparent equilibrium constants for each acid-amine complex were determined by an equilibrium model. In the case of succinic acid, the formation of a bisuccinate anion played an important role in the stoichiometry of the acid-amine complex.     

Adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus)

We examined adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus), a species in which close relatedness among philopatric males and high paternity uncertainty should minimize both aggressive and affiliative behavior by males toward infants. As expected, male-infant interactions were extremely rare during this 10-month field study. None were observed in over 236 hr of observation on a cohort of six infants (0 – 13 months old). The 29 interactions observed ad lib involved 5 of the 6 infants and 9 of the 16 adult males in the group. All of the male-infant interactions were affiliative, but extremely brief. The median duration of interactions was only 0.33 min, and none lasted longer than 1.52 min. Infants always initiated, and nearly always terminated, their interactions with adult males. The indifference that appears to characterize muriqui male-infant interactions differs from the ways in which other male primates interact with infants when protection of genetic interests or investment in mating effort are involved.