1,210 publications from this institution
Victor, Benjamin C., Vasquez-Yeomans, Lourdes, Valdez-Moreno, Martha, Wilk, Leslie, Jones, David L., Lara, Monica R., Caldow, Chris, Shivji, Mahmood (2010): The larval, juvenile, and adult stages of the Caribbean goby, Coryphopterus kuna (Teleostei: Gobiidae): a reef fish with a pelagic larval duration longer than the post-settlement lifespan. Zootaxa 2346: 53-61, DOI: 10.5281/zenodo.205337
Microplastic contamination poses a significant threat to agroecosystem functioning, provoking a move away from the use of conventional oil-based plastics in agriculture, to biodegradable alternatives that may be degraded over a shorter timescale. The impact of these bioplastics on plant and soil health, however, has received relatively little attention. Here, we investigated the effect of soil loading (0.01%, 0.1%, 1% and 10%) of biobased microplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) on soil and plant (Zea mays L.) health and function. We showed that PHBV caused a dose-dependent reduction in plant growth and foliar nitrogen (N) content while untargeted metabolite analysis revealed significant shifts in foliar metabolic function. These results were also reflected in soil, where PHBV led to reduced plant availability of both ammonium and nitrate. Soil 14C-isotope tracing and 16S metabarcoding revealed that PHBV suppressed microbial activity, reduced bacterial diversity and shifted microbial community structure, inducing a major shift in soil metabolic pathways, and thus functioning. Overall, our data suggests that the bioplastic PHBV is not environmentally benign and that contamination levels as low as 0.01% (0.01 mg kg-1) can induce significant short-term changes in both plant and soil microbial functioning, with potential implications for long term agroecosystem health.
Forest creation has the potential to reduce biodiversity loss and mitigate climate change but, tree disease emergence may counteract this. Further, given decadal timescales required for forest establishment, climate change is increasingly likely to act as a filter on plant community assembly. In the temperate lowlands succession takes 30 to 50 years for non-forest land to establish woodland plant assemblages, while the timescales required for new forest to sequester carbon suggest unassisted succession will be too slow for net zero 2050 targets. However, if plantations can establish faster than succession it would be beneficial to recommend planting native species as soon as possible. We explore scenarios of broadleaved woodland development across Wales, UK, as a case study area. We use a suite of empirical species niche models for British plants to estimate the potential species composition of forests with, and without, projected climate change. Additionally, we examine how tree canopy composition alters if Fraxinus excelsior is widely impacted by ash-dieback ( Hymenoscyphus fraxineus ). The results suggest soil total carbon and nitrogen could achieve baseline broadleaved forest values in less than 30 years. However only timber and woody flora species groups showed diversity surpassing baseline broadleaved forest diversity, with nectar plants and ancient woodland indicator species failing to reach baseline equivalents within 30 years; although complete congruence is unlikely given baseline forests could be hundreds of years old. Where Fraxinus excelsior was removed from the species pool we predicted that a scrub phase will persist or, if present, Acer pseudoplatanus will become the canopy dominant. The heavier shade cast this species is likely to result in differences in species composition of the understory and ground flora diversity is likely to decrease. Reliance on unassisted succession will also depend critically on (a) dispersal from local source populations and (b) on establishment filters that could be severe in landscapes with high management intensity history. These findings indicate that leaving the UK’s fragmented habitats to relying on already degraded successional processes could lead to poor afforestation outcomes. Highlights Afforestation can mitigate global change but tree disease makes outcomes uncertain Afforestation methods establishment timescales and time for benefits to occur We model afforestation and predict how soils and plants change with climate Ash loss from die-back is replaced by low low-canopy woodland / scrub over 30 years Afforestation achieves baseline forest values for some variables within 30 years
Organic acids have been hypothesised to play a central role in long-term soil pedogenic processes such as podzolisation and also in short-term rhizosphere processes such as nutrient mobilisation. Their spatial and temporal patterns in soil, however, are poorly understood. This study was designed to quantify the rate of microbial decomposition of three low molecular weight organic acids (citrate, oxalate and acetate) as a function of soil depth (O, A, E, B and C horizons) in three podzolic coniferous forest soils and to assess their contribution to total soil CO2 fluxes. Soil solution extraction indicated that generally, most organic acids were present in the highest concentration in surface O horizons (10–100μM) declining with soil depth. Correspondingly, the rate of organic acid mineralisation was also greatest in the surface organic horizons. In contrast, the mineral horizons possessed low rates of biodegradation which appeared not to be due to a lack of microbial activity but moreover due to strong sorption to the solid phase preventing microbial uptake. Concentration-dependent mineralisation experiments indicated that decomposition could be adequately described by a single Michaelis–Menten kinetics equation. The results showed that generally most horizon samples had the greatest mineralisation capacity for citrate or oxalate (V max=<1–340nmolg−1 h−1) in comparison to acetate. The V max values typically declined with soil depth. K M values ranged from 10 to 7000μM, however, if adsorption was accounted for the K M values decreased (<1–5000μM) especially in B horizons. Calculations of the contribution of organic acids to total soil respiration indicated that between <0.1 and 47% of total CO2 production from an individual horizon could be accounted for by organic acid mineralisation alone. The findings are discussed in the context of soil forming and rhizosphere processes.
No abstract is provided for this article.
No abstract is provided for this article.
Starch gel electrophoresis was employed to estimate the levels of genetic variation among five entities of the Macrozamia heteromera (Zamiaceae) group which can be recognised on morphological grounds. A total of 168 specimens were assayed for 12 enzyme systems coded by 16 loci. Low levels of genetic variation were observed with 10 of the 17 loci (58%) being monomorphic. Mean percent polymorphic loci (P=26%), number of alleles per locus (A=1.3) and expected heterozygosity (H e=0.06) were all low. Although notably morphologically different, the species are very similar genetically. The overall G st value of 0.10 and the high genetic identity value of (range 0.92–0.97) suggest that these species are either recently evolved or they are depauperate in genetic variation due to inbreeding.
Research Article| September 01 1972 Degradation of sclerotan, a β-(1→3)glucan, by enzymes from fungi parasitic on sclerotia J S D Bacon; J S D Bacon Search for other works by this author on: This Site PubMed Google Scholar A H Gordon; A H Gordon Search for other works by this author on: This Site PubMed Google Scholar D Jones D Jones Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1972) 129 (2): 27P–28P. https://doi.org/10.1042/bj1290027Pb Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation J S D Bacon, A H Gordon, D Jones; Degradation of sclerotan, a β-(1→3)glucan, by enzymes from fungi parasitic on sclerotia. Biochem J 1 September 1972; 129 (2): 27P–28P. doi: https://doi.org/10.1042/bj1290027Pb Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1972 London: The Biochemical Society1972 Article PDF first page preview Close Modal You do not currently have access to this content.
Honey mesquite (Prosopis glandulosa Torr.) is a problem plant in much of the southwestern USA because it reduces forage production for livestock, interferes with livestock handling and reduces off-site water yield.Aerial spraying a 1:1 mixture of clopyralid (3,6-dichloro-2-pyridinecarboxylic acid, mono- ethanolamine salt) and triclopyr (3,5,6-trichloro-2-pyridinyloxy- acetic acid, butyoxyethyl ester) at 0.28 kg ae ha1 + 0.28 kg ae ha 1 usually achieves high above-ground (top-kill) and whole plant (root-kill) mortality, but limits multiple-use options of livestock and wildlife production because little mesquite foliage is left to provide screening cover for wildlife.In addition, most surviving plants resprout from basal meristems and will become multistemmed plants.Some managers treat mesquite in strips or blocks, leaving untreated areas for screening cover, but these areas become increasingly non-productive for livestock and wildlife forage.The objective of this study was to evaluate the potential of aerial sprays of clopyralid alone at 0.28 kg ha 1 to convert thickets of mature, multi-stemmed mesquite to savannas by reducing mesquite foliage amount to an intermediate level (by 50-70%), yet preserving apical dominance and limiting basal sprouting.The clopyralid treatment was compared to an untreat- ed control and aerial sprays of 0.28 kg ha 1 clopyralid + 0.28 kg ha1 triclopyr on 2 sites.The clopyralid treatment reduced foliage amount tree 1, canopy area treed, and stand-level mesquite cover by > 57% when compared untreated areas, and 73% of surviving trees maintained apical dominance.Apical dominance was main- tained in > 70% of trees not totally top-killed if at least 20% of the original canopy survived and produced foliage following the spray year.Percent root-kill in the clopyralid-only treatment dif- fered between sites (34 and 10%).The lower root-kill on one site was attributed to rainfall that occurred 2 days before and one day after spraying.The clopyralid+triclopyr treatment reduced foliage on original canopies by > 96% and mesquite cover by 82% on both sites.Root-kill was > 52% on both sites but only 37 % of surviving plants maintained apical dominance.Resultssuggest that clopyralid at 0.28 kg ha 1 may be effective for con- verting mesquite thickets to savanna and may aid in multiple-use management.
