A global synthesis reveals biodiversity-mediated benefits for crop production

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society

A global synthesis reveals biodiversity-mediated benefits for crop production

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society. [Abstract copyright: Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Euryhaline rotifer Proales similis as initial live food for rearing fish with small mouth

The SS-type rotifer Brachionus rotundiformis is a common initial food for rearing fish larvae with a small mouth. However, there are commercially important fish species whose mouth sizes are too small to feed on SS-type rotifers. In 2004, we isolated a small (body length=82.7±10.9μm; body width 40.5±6.4μm), flexible, and iloricate rotifer, Proales similis from an estuary in Okinawa, Japan. Under laboratory conditions (25°C, 2-25ppt) P. similis produced its first offspring on 2.5 to 2.8days after hatching, and produced 4.3 to 7.8 offspring within 4.0 to 4.7days life span. Batch cultured P. similis fed Nannochloropsis oculata suspension at 28.8μg dry weight ml-1 and cultured at 25°C, 25ppt filtered seawater, increased exponentially from 25 to 2400ind ml-1 after 11days of culture with an overall intrinsic rate of natural increase (r) of 0.42day-1. The growth rate of P. similis was not significantly different when fed fresh N. oculata and super fresh Chlorella vulgaris-V12R. Total lipid per wet weight of P. similis fed by N. oculata and C. vulgaris were 2.4 and 2.6%, respectively. The compositions of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (ARA) of P. similis fed N. oculata were 23.2, 0.0 and 5.3%, respectively, while these were 11.0, 17.5 and 0.5% respectively, when fed C. vulgaris. The use of P. similis to feed small mouth fish including seven-band grouper Epinephelus septemfasciatus, rusty angelfish Centropyge ferrugata, and humphead wrasse Cheilinus undulatus showed that it is an excellent starter food for these species because of their high selectivity index and improved survival. In addition, P. similis was ingested by Japanese eel Anguilla japonica larvae with a complicated digestive system. The use of P. similis as starter feed for small mouth fish larvae is highly recommended

Coiled Tubing Drilling and Real-Time Sensing: Enabling Prospecting Drilling in the 21st Century?

Tier 1 mineral resource discoveries are critical to maintaining Australia’s, and indeed the world’s, mineral resource inventory without continuing decline in the grade of mined resources. Such discoveries are becoming less common because, increasingly, remaining prospective, underexplored areas are obscured by deep, barren cover. We argue that improving the rate of Tier 1 discoveries obscured by deep, barren cover requires a step change in mineral exploration techniques that may be provided by “prospecting drilling,” i.e., extensive drilling programs that map mineral systems beneath cover, enabling geophysical and geochemical vectoring toward deposits. The technological platform for prospecting drilling must include low-cost drilling due to the dense subsurface sampling required. Low-cost drilling may be provided by transferring coiled tubing drilling technology, with its continuous drill pipe on a reel, from the oil and gas sector. Key challenges to the deployment of coiled tubing drilling in mineral exploration, i.e., its rate of penetration in hard rocks, the durability of coiled tubing, and the recovery of cuttings, are being assessed and addressed by researchers of the Deep Exploration Technologies Cooperative Research Centre (DET CRC).The optimum technology platform for prospecting drilling would be coiled tubing drilling complemented by downhole and top-of-hole sensing, providing realtime petrophysics, structure/rock fabric, geochemistry, and mineralogy. The first manifestation of real-time, downhole sensing is our newly developed autonomous sonde that is deployed by the driller and logs natural gamma radiation as the dill rods are pulled. Our experimentation on real-time, top-of-hole sensing (on drill cuttings from diamond cored holes) has demonstrated cost-effective, rapid, repeatable, and accurate determination of geochemistry and mineralogy with the necessary depth fidelity. The rationale for prospecting drilling is provided by two examples: (1) a dataset of antimony from the Kalgoorlie district of Western Australia, which shows that subsampling at a 2-km spacing would map the mineral system and enable vectoring toward the contained deposits, and (2) analysis of hypogene alteration systems of iron oxide-copper-gold (IOCG) deposits in South Australia that presents the possibility of vectoring toward the deposits within such systems starting from >10 km distant. At the target cost of $50/m, coiled tubing drilling could cost effectively undertake prospecting drilling in large, covered provinces, such as the IOCG prospective Gawler craton of South Australia