Ethenzamide–gentisic acid–acetic acid (2/1/1)

In the title co-crystal solvate, 2-ethoxy­benzamide–2,5-dihydroxy­benzoic acid–ethanoic acid (2/1/1), 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy­benzamide) and gentisic acid (systematic name: 2,5-dihydroxy­benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol­ecular assembly held together by N—H⋯O and O—H⋯O hydrogen bonds. This assembly features two symmetry-independent mol­ecules of ethenzamide, forming supra­molecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H⋯O [O⋯O = 2.5446 (15) and 2.5327 (15) Å] and less strong N—H⋯O [N⋯O = 2.9550 (17) and 2.9542 (17) Å] hydrogen bonds. The overall crystal packing features several C—H⋯O and π–π stacking inter­actions [centroid–centroid distance = 3.7792 (11) Å]

Soil nutrients and beta diversity in the Bornean Dipterocarpaceae: evidence for niche partitioning by tropical rain forest trees

1   The relative importance of niche- and dispersal-mediated processes in structuring diverse tropical plant communities remains poorly understood. Here, we link mesoscale beta diversity to soil variation throughout a lowland Bornean watershed underlain by alluvium, sedimentary and granite parent materials ( c . 340 ha, 8–200 m a.s.l.). We test the hypothesis that species turnover across the habitat gradient reflects interspecific partitioning of soil resources. 2   Floristic inventories (≥ 1 cm d.b.h.) of the Dipterocarpaceae, the dominant Bornean canopy tree family, were combined with extensive soil analyses in 30 (0.16 ha) plots. Six samples per plot were analysed for total C, N, P, K, Ca and Mg, exchangeable K, Ca and Mg, extractable P, texture, and pH. 3   Extractable P, exchangeable K, and total C, N and P varied significantly among substrates and were highest on alluvium. Thirty-one dipterocarp species ( n  = 2634 individuals, five genera) were recorded. Dipterocarp density was similar across substrates, but richness and diversity were highest on nutrient-poor granite and lowest on nutrient-rich alluvium. 4   Eighteen of 22 species were positively or negatively associated with parent material. In 8 of 16 abundant species, tree distribution (≥ 10 cm d.b.h.) was more strongly non-random than juveniles (1–10 cm d.b.h.), suggesting higher juvenile mortality in unsuitable habitats. The dominant species Dipterocarpus sublamellatus (> 50% of stems) was indifferent to substrate, but nine of 11 ‘subdominant’ species (> 8 individuals ha −1 ) were substrate specialists. 5   Eighteen of 22 species were significantly associated with soil nutrients, especially P, Mg and Ca. Floristic variation was significantly correlated with edaphic and geographical distance for all stems ≥ 1 cm d.b.h. in Mantel analyses. However, juvenile variation (1–10 cm d.b.h.) was more strongly related to geographical distance than edaphic factors, while the converse held for established trees (≥ 10 cm d.b.h.), suggesting increased importance of niche processes with size class. 6   Pervasive dipterocarp associations with soil factors suggest that niche partitioning structures dipterocarp tree communities. Yet, much floristic variation unrelated to soil was correlated with geographical distance between plots, suggesting that dispersal and niche processes jointly determine mesoscale beta diversity in the Bornean Dipterocarpaceae. Journal of Ecology (2005) doi: 10.1111/j.1365-2745.2005.01077.xPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72822/1/j.1365-2745.2005.01077.x.pd

Peat Characterization and Uptake of Nickel (II) and Cobalt (II) in a Saprist Peat Column

In this study, fibrist and saprist sphagnum peat soils taken from a bog in Torbay, Newfoundland (Canada) were characterized. The saprist and fibrist peat soils had wet bulk densities of 0.65 and 0.60 g/cm3, respectively, and cation-exchange capacities of 70 and 45 meq/100 g, respectively. The pH of both peat soils was 4.2 and the soils were amorphous for the most part; however, the fibrist peat was more porous than the saprist peat. Results of Fourier transform infrared spectroscopy and 13carbon nuclear magnetic resonance suggested the presence of carboxylic acid, alcoholic hydroxyl, phenolic hydroxyl, amine and amide functional groups in both peats. The less reported amine and amide groups may have been observed because non-destructive characterization techniques were employed. The saprist peat was studied as an Ni2+ and Co2+ adsorbent in a vertical downflow fixed-bed column and at the end of each column experiment, metal ions in the upper layer of the peat were desorbed with HCl. The metal sorption capacity of the saprist peat increased with decreasing flow rate and overall the sorption capacity of Ni2+ was two times greater than the sorption capacity of Co2+. Ni2+ may have been retained by a combination of ion exchange and complexation, while Co2+ may have been retained only by complexation

Data from: Soil carbon response to woody plant encroachment: Importance of spatial heterogeneity and deep soil storage

1. Recent global trends of increasing woody plant abundance in grass-dominated ecosystems may substantially enhance soil organic carbon (SOC) storage and could represent a strong carbon (C) sink in the terrestrial environment. However, few studies have quantitatively addressed the influence of spatial heterogeneity of vegetation and soil properties on SOC storage at the landscape scale. In addition, most studies assessing SOC response to woody encroachment consider only surface soils, and have not explicitly assessed the extent to which deeper portions of the soil profile may be sequestering C. 2. We quantified the direction, magnitude, and pattern of spatial heterogeneity of SOC in the upper 1.2 m of the profile following woody encroachment via spatially-specific intensive soil sampling across a landscape in a subtropical savanna in the Rio Grande Plains, USA, that has undergone woody proliferation during the past century. 3. Increased SOC accumulation following woody encroachment was observed to considerable depth, albeit at reduced magnitudes in deeper portions of the profile. Overall, woody clusters and groves accumulated 12.87 and 18.67 Mg C ha-1 more SOC compared to grasslands to a depth of 1.2 m. 4. Woody encroachment significantly altered the pattern of spatial heterogeneity of SOC to a depth of 5 cm, with marginal effect at 5-15 cm, and no significant impact on soils below 15 cm. Fine root density explained greater variability of SOC in the upper 15 cm, while a combination of fine root density and soil clay content accounted for more of the variation in SOC in soils below 15 cm across this landscape. 5. Synthesis: Substantial SOC sequestration can occur in deeper portions of the soil profile following woody encroachment. Furthermore, vegetation patterns and soil properties influenced the spatial heterogeneity and uncertainty of SOC in this landscape, highlighting the need for spatially specific sampling that can characterize this variability and enable scaling and modeling. Given the geographic extent of woody encroachment on a global scale, this undocumented deep soil C sequestration suggests this vegetation change may play a more significant role in regional and global C sequestration than previously thought