Wokker. Notes on a Surrealist comic strip

This essay explores the creation and development of a British comic strip, Wokker (1971-1999), and its connections with the surrealist movement. Although the strip is remarkable for its content and formalist properties, it remains obscure both because of its publishing circumstances, and because it does not fit easily into a history of comics. Rather it can be argued that its conceptual roots can be traced to the artistic ferment that happened in Paris in the 1920s (with Breton as a key reference point), and that it represents a very English, and late-flowering, example of the surrealist idea

The production, allocation and cycling of carbon in a forest on fertile <i>terra preta</i> soil in eastern Amazonia compared with a forest on adjacent infertile soil

<div><p> <b><i>Background:</i></b><i>Terra preta do indio</i> or ‘dark earth’ soils formed as a result of a long-term addition of organic matter by indigenous peoples in Amazonia.</p> <p> <b><i>Aims:</i></b> Here we report on the first study of productivity, allocation and carbon cycling from a <i>terra preta</i> plot in eastern Amazonia (Caxiuanã, Pará, Brazil), and contrast its dynamics with a nearby plot on infertile soil (ferralsols).</p> <p> <b><i>Methods:</i></b> We determined total net primary production (NPP) for fine roots, wood, and canopy and total autotrophic respiration (rhizosphere, wood, and canopy respiration) from two 1-ha plots on contrasting soils.</p> <p> <b><i>Results:</i></b> Both gross primary productivity (GPP) (35.68 ± 3.65 vs. 32.08 ± 3.46 Mg C ha⁻¹ year⁻¹) and carbon use efficiency (CUE) (0.44 ± 0.06 vs. 0.42 ± 0.05) were slightly higher at the <i>terra preta</i> plot. Total NPP (15.77 ± 1.13 Mg C ha⁻¹ year⁻¹ vs. 13.57 ± 0.60 Mg C ha⁻¹ year⁻¹) and rates of fine root production (6.41 ± 1.08 vs. 3.68 ± 0.52 Mg C ha⁻¹ year⁻¹) were also greater at the <i>terra preta</i> plot vs. the tower plot.</p> <p> <b><i>Conclusions:</i></b> Forests on <i>terra preta</i> soil fix slightly more carbon and allocate slightly more of that carbon towards growth than forests on the infertile plot, which leads to greater total NPP, which was disproportionately allocated to fine roots. However, since increased fine root NPP was partially offset by increased heterotrophic soil respiration, the increased root growth was unlikely to greatly enhance soil carbon stocks in <i>terra preta</i> soils.</p> </div

Basin-wide variations in Amazon forest nitrogen-cycling characteristics as inferred from plant and soil ¹⁵N:¹⁴N measurements

<div><p> <b><i>Background:</i></b> Patterns in tropical forest nitrogen cycling are poorly understood. In particular, the extent to which leguminous trees in these forests fix nitrogen is unclear.</p> <p> <b><i>Aims:</i></b> We aimed to determine factors that explain variation in foliar δ¹⁵N (δ¹⁵N_F) for Amazon forest trees, and to evaluate the extent to which putatively N₂-fixing Fabaceae acquire nitrogen from the atmosphere.</p> <p> <b><i>Methods:</i></b> Upper-canopy δ¹⁵N_F values were determined for 1255 trees sampled across 65 Amazon forest plots. Along with plot inventory data, differences in δ¹⁵N_F between nodule-forming Fabaceae and other trees were used to estimate the extent of N₂ fixation.</p> <p> <b><i>Results:</i></b> δ¹⁵N_F ranged from −12.1‰ to +9.3‰. Most of this variation was attributable to site-specific conditions, with extractable soil phosphorus and dry-season precipitation having strong influences, suggesting a restricted availability of nitrogen on both young and old soils and/or at low precipitation. Fabaceae constituted fewer than 10% of the sampled trees, and only 36% were expressed fixers. We estimated an average Amazon forest symbiotic fixation rate of 3 kg N ha⁻¹ year⁻¹.</p> <p> <b><i>Conclusion:</i></b> Plant δ¹⁵N indicate that low levels of nitrogen availability are only likely to influence Amazon forest function on immature or old weathered soils and/or where dry-season precipitation is low. Most Fabaceae species that are capable of nodulating do not fix nitrogen in Amazonia.</p> </div

The productivity, metabolism and carbon cycle of two lowland tropical forest plots in south-western Amazonia, Peru

<div><p> <b><i>Background:</i></b> The forests of western Amazonia are known to be more dynamic that the better-studied forests of eastern Amazonia, but there has been no comprehensive description of the carbon cycle of a western Amazonian forest.</p> <p> <b><i>Aims:</i></b> We present the carbon budget of two forest plots in Tambopata in south-eastern Peru, western Amazonia. In particular, we present, for the first time, the seasonal variation in the detailed carbon budget of a tropical forest.</p> <p> <b><i>Methods:</i></b> We measured the major components of net primary production (NPP) and total autotrophic respiration over 3–6 years.</p> <p> <b><i>Results:</i></b> The NPP for the two plots was 15.1 ± 0.8 and 14.2 ± 1.0 Mg C ha⁻¹ year⁻¹, the gross primary productivity (GPP) was 35.5 ± 3.6 and 34.5 ± 3.5 Mg C ha⁻¹ year⁻¹, and the carbon use efficiency (CUE) was 0.42 ± 0.05 and 0.41 ± 0.05. NPP and CUE showed a large degree of seasonality.</p> <p> <b><i>Conclusions:</i></b> The two plots were similar in carbon cycling characteristics despite the different soils, the most notable difference being high allocation of NPP to canopy and low allocation to fine roots in the Holocene floodplain plot. The timing of the minima in the wet–dry transition suggests they are driven by phenological rhythms rather than being driven directly by water stress. When compared with results from forests on infertile forests in humid lowland eastern Amazonia, the plots have slightly higher GPP, but similar patterns of CUE and carbon allocation.</p> </div

Unsummarized soil 15N data

soil 15N data for individual samples. not summarized. includes excluded data for further reference

List of plot data used in the present study from Evolutionary heritage influences Amazon tree ecology

List of plots encompassing the Floristic tree inventories for 577 plots compiled from RAINFOR database, with their respective coordinates in Latitude (Lat.) and Longitude (Long.) , area in hectare, number of individuals with diameter equal or superior to 10 cm, number of species, number of genera and data contributors. Plots with long term data and minimum of 2 years census interval (257) are assigned

Phylogeny of 497 Amazonian tree genera from Evolutionary heritage influences Amazon tree ecology

Phylogeny of 497 Amazonian tree and palm genera, with branches coloured according to wood density, potential tree size, maximum tree growth and mortality rates

Comparison between published values of phylogenetic signal and values found in the present study from Evolutionary heritage influences Amazon tree ecology

Comparison between published values of phylogenetic signal for traits of tropical forest trees measured by Blomberg's K statistic. Bar colour indicates the different studies [1-5]; bars in black are represented by traits calculated in the present study and shades of grey show values for published studies. Bars with negative values represent absence of phylogenetic signal

Supporting reults from Evolutionary heritage influences Amazon tree ecology

Model comparison; Loadings for Phylogenetic Principal Componets Analysis (PPCA); Sensitivity analyse

Methods for calculating trait intrinsic value from Evolutionary heritage influences Amazon tree ecology

Description of the methods used to calculate intrinsic trait values to account for the effect of variation in environmental conditions among plot