Search

To extend present knowledge of communities of wood decay fungi in native forests, basidiomycetes and ascomycetes were isolated from within 15 fallen stems in beech (Nothofagus, Nothofagaceae) forests in the South Island of New Zealand. Fungal species were identified as precisely as possible using traditional culturing and molecular approaches. The internal distribution of species within stems was determined. Common fungi that occupied significant portions of stems were Ganoderma applanatum sensu Wakefield, Australoporus tasmanicus, Inonotus nothofagi, Pleurotus purpureo-olivaceus, and an unidentified hymenochaetaceous species. Richness and diversity of basidiomycete species were greater in stems of red beech (Nothofagus fusca (Hook. f.) Oerst.) and silver beech (Nothofagus menziesii (Hook. f.) Oerst.) than in those of matai (Prumnopitys taxifolia (Banks & Sol. ex D. Don) de Laub.; Podocarpaceae) and tawa (Beilschmiedia tawa (A. Cunn.) Kirk; Lauraceae), as determined from earlier studies in podocarp hardwood and beech indigenous forests. There was greater similarity in the species composition of basidiomycete fungi colonising the three beech species compared with those colonising rimu (Dacrydium cupressinum Sol. ex Lamb.; Podocarpaceae), tawa, and matai. Based on observations in this study and on international research on the effects of selective logging on basidiomycete biodiversity, the decision to restrict to 50% the extraction of wood following storm damage in beech forests on the West Coast of the South Island appears to have been appropriate.Key words: fungal biodiversity, decomposer fungi, decay of fallen Nothofagus stems, New Zealand indigenous forest ecology.Dans le but d'ameliorer notre connaissance des communautes de champignons de carie dans les forets indigenes, des basidiomycetes et des ascomycetes ont ete isoles dans le bois de 15 tiges au sol dans des forets de hetres (Nothofagus, Nothofagacees) de l'Ile du Sud en Nouvelle-Zelande. Les especes fongiques ont ete identifiees aussi precisement que possible en utilisant la mise en culture traditionnelle et les approches moleculaires. La distribution des especes a l'interieur des tiges a ete determinee. Les champignons communs qui occupaient des portions importantes des tiges etaient Ganoderma applanatum sensu Wakefield, Australoporus tasmanicus, Inonotus nothofagi, Pleurotus purpereo-olivaceus et une espece non identifiee d'hymenochaetacees. La richesse et la diversite des especes de basidiomycetes etaient plus grandes dans les tiges du hetre rouge (Nothofagus fusca (Hook. f.) Oerst.) et du hetre argente (Nothofagus menziesii (Hook. f.) Oerst.) que dans celles du matai (Prumnopitys taxifolia (Banks & Sol. ex D. Don) de Laub.; Podocarpacees) et du tawa (Beilschmiedia tawa (A. Cunn.) Kirk; Lauracees), tel que determine lors d'etudes precedentes dans des forets indigenes de feuillus podocarpes et de hetres. Il y avait une plus grande similitude dans la composition en especes de champignons basidiomycetes qui colonisaient les trois especes de hetres comparativement a ceux qui colonisaient le rimu (Dacrydium cupressinum Sol. ex Lamb.; Podocarpacees), le tawa et le matai. Sur la base des observations faites dans le cadre de cette etude et de travaux de recherche internationaux sur les effets de la coupe selective sur la biodiversite des basidiomycetes, la decision de restreindre a 50 % l'extraction de bois a la suite de dommages dus aux tempetes dans les forets de hetres de la cote ouest de l'Ile du Sud semble avoir ete appropriee. [Traduit par la Redaction]Mots-cles : biodiversite fongique, champignons decomposeurs, carie des tiges au sol de Nothofagus, ecologie des forets indigenes de Nouvelle-Zelande., 1. IntroductionThe decay of woody matter is crucial to the overall forest ecosystem. The release of carbon and minerals during this process offsets the reverse actions of carbon assimilation and [...]

Early detection of bark- and wood-boring beetles is critical to support the eradication of recently established populations in novel regions. Flight intercept traps baited with semiochemical lures are essential for surveillance and population monitoring of introduced insects. We present laboratory and field data to test potential improvements in trap sensitivity to detect Hylastes ater (Paykull), Hylurgus ligniperda (Fabricius) (Coleoptera:Scolytinae), and Arhopalus ferus (Mulsant) (Coleoptera:Cerambycidae). We evaluated the effects of type and permeability of plastic material on release rates of host-plant volatiles and the addition of the pheromone racemic E-fuscumol on beetle species catch within an exotic Pinus radiata (D. Don) plantation forest. We trapped 228,278 H. ligniperda, 91 H. ater, and 2,504 A. ferus over two experiments. Our results show strong attraction of H. ligniperda to host-plant volatiles with a positive relationship between increased release rates and trap catch. H. ater follows this trend, with attraction to ethanol and (–)-β-pinene. H. ligniperda was more strongly attracted to host volatiles than H. ater, the average ratio between baited and unbaited traps being 51.25:1 and 3.75:1, respectively for each species. There was no effect of host-plant volatiles or release rate on A. ferus catch, but a weak attraction by A. ferus to racemic E-fuscumol. Overall, we demonstrate species-specific differences in Coleoptera attraction to host-plant volatile release rates and semiochemical blends. Results demonstrate mechanisms to improve trap catch of H. ligniperda and H. ater. Racemic E-fuscumol shows some promise for A. ferus, but further investigation is required to determine whether chirality affects attraction. [ABSTRACT FROM AUTHOR]

Breeding ryegrass for reduced inorganic phosphorus (Pi) concentrations in leaf vacuoles could lower pasture P fertiliser requirements with economic and environmental benefits. We investigated foliar Pi% accumulation characteristics of a range of ryegrass cultivars and ecotypes in glasshouse experiments, and ryegrass cultivars from two field trials. Pi in ryegrass was also compared with Pi in cocksfoot, tall fescue, prairie grass and Phalaris in a glasshouse experiment. Pi expressed as a percentage of leaf total phosphorus was higher (average 82.5%) in the older ryegrass cultivars – Ruanui, and Nui and the New Zealand hill country ecotypes (85%) than in more recently bred cultivars like Aberdart and One50 (74.7%). In the other grass species, foliar Pi% was lowest in prairie grass, intermediate in tall fescue with the highest values in cocksfoot, Phalaris and ryegrass. The results suggest that including a lower Pi concentration in future ryegrass breeding programmes might improve ryegrass P use efficiency without compromising growth rates. [ABSTRACT FROM AUTHOR]

Austropuccinia psidii, cause of myrtle rust, has spread globally where Myrtaceae occur. Multiple strains of A. psidii have been identified, including a unique strain found only in South Africa. The South African strain is a biosecurity concern for species of Myrtaceae worldwide. This is because preliminary testing of South African Myrtaceae suggests it could have a wide host range, and thus has the potential to be invasive. In this study, we assessed the ability of the South African strain to infect other species of Myrtaceae by testing the susceptibility of New Zealand provenance Myrtaceae. Seedlings of four native New Zealand Myrtaceae species (Metrosideros excelsa, Leptospermum scoparium, Kunzea robusta, and Kunzea linearis) were artificially inoculated in South Africa with a single‐uredinium isolate of the South African strain. Fourteen days after inoculation, uredinia, and in many cases telia, had developed on the young leaves and stems of all four host species, which led to shoot tip dieback in the more severe cases. When comparisons were made between the species, K. robusta was the least susceptible to the South African strain of A. psidii, while L. scoparium and M. excelsa were the most susceptible. While only a limited number of seed families were tested, only a small proportion of the seedlings showed resistance to infection by the South African strain. This preliminary testing highlights the potential invasive risk the South African strain poses to global Myrtaceae communities, including New Zealand Myrtaceae. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although unmanned aerial vehicles (UAVs) are increasingly used to deliver small‐scale aerial pesticide applications, there remains uncertainty over their efficiency in terms of uniformity of spray deposition and their application efficiency. Consequently, a field study was designed to quantify factors influencing the uniformity of spray deposition from a multi‐rotor UAV that is operated commercially in New Zealand. Two sampling systems for measuring spray deposition, a continuous horizontal string and steel plates placed on the ground were compared. RESULTS: The spray deposit distribution characteristics and calculated lane separation values (distance between flight lines that produces a maximum coefficient of variation of 30% for spray deposits) were strongly influenced by wind speed, nozzle position, release height, ground speed and droplet size. Lane separation values ranged from 1 to > 5 m. Swath distribution parameters (spread and position of peak deposition) derived from plates were not significantly different from those derived from string. However, total deposition on strings relative to plates increased with small droplets. Reducing plate sampling intensity from 0.25 m intervals to 0.5 m and even 1.0 m had only a minor effect on estimates of swath parameter values. CONCLUSIONS: The potential for precision spraying from UAV platforms has yet to be achieved with improvements required in hardware and software. Further, mechanistic models are needed to quantify how complex interactions among multiple operating and meteorological variables influence spray deposition. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]