Understanding and Applying Ecological Principles in Cities

Renaturing cities requires a thorough understanding of how plants and animals interact with the urban environment and humans. But cities are a challenging environment for ecologists to work in, with high levels of heterogeneity and rapid rates of change. In addition, the hostile conditions often found in cities mean that each city, and region of a city, can have their own unique geographical context. In this chapter, we contrast urban ecological research in the UK and Brazil, to demonstrate the challenges and approaches needed to renature cities. In so doing, we provide a platform for global transferability of these locally contextualised approaches. The UK has a long history of urbanisation and, as a result of increasing extinction debts over 200 years, well-established urban ecological research. Research is generally focused on encouraging species back into the city. In contrast, Brazil is a biodiversity hotspot with relatively rich urban flora and fauna. This rich ecosystem is imperilled by current rapid urbanisation and lack of support for urban nature by city-dwellers. By working together and transferring expertise, UK and Brazilian researchers stand a better chance of understanding urban ecological processes and unlocking renaturing processes in each location. We present one such method for applying ecological knowledge to cities, so-called Ecological Engineering, in particular by discussing ecomimicry—the adaptive approach needed to apply global ecological principles to local urban challenges. By reading the ecological landscape in which urban developments sit and applying tailored green infrastructure solutions to new developments and greenspaces, cities may be able to reduce the rate at which extinction debt is accumulated

Particle-stabilized water droplets that sprout millimeter-scale tubes

A layer of colloidal particles will become irreversibly trapped at a fluid–fluid interface if they exhibit partial wettability with both fluid phases. This effect has been exploited to create Pickering emulsions, armored bubbles, and new materials of various kinds. When the interfaces are densely coated with particles, they behave like rigid elastic sheets with moduli that are proportional to the underlying interfacial tension. The interfaces are permeable, a characteristic that can, for example, lead to compositional ripening of Pickering emulsions Here we show that when particle-stabilized water droplets are created in a bath of toluene with ethanol, millimeter-scale tubes are observed to sprout from the top of the droplets. Growth is driven by the ethanol partitioning from the toluene into the water which leads to an internal overpressure. Vertical growth occurs over many minutes; finally the tube buckles when it can no longer support its own weight (Figure 1). There are several different growth modes controlled by the concentration of ethanol and of silica particles.[1] An alternative way to manipulate the system is by using a different alcohol, leading to insight on the role of the underlying three-fluid phase diagram. Our work paves the way for future studies of droplet growth because the liquid droplets and the interfacial properties can be independently studied. Please click Additional Files below to see the full abstract

Perceptions and Attitudes: Analyzing Opinion Leaders in Relation to Genetically Modified Foods

Controversial issues in agriculture arise, and it falls on opinion leaders to disseminate information to their networks and the public. Agriculturalists are often blamed for not taken consumers’ concerns into consideration. This study sought to add to previous research by identifying the current perceptions of Florida agricultural leaders toward GM food, what percentage of them identify as opinion leaders with respect to GM food, and what they identify as sources of information regarding GM food. Through an online survey, the trust and attitudes towards GM foods and science, of agricultural leaders who participated in the Wedgworth Leadership Institute, were measured as well as their sources and channels of information. By identifying opinion leaders and helping them understand how to create and disseminate effective agricultural messages, agricultural educators and communicators can reach consumers and reduce the current knowledge gap more successfully. The results of this study confirm previous literature which states that both “what one knows” and “who one knows” impacts the level of influence an opinion leader may have with their peers. Agricultural educators should work with both agricultural opinion leaders and communicators to identify current consumer perceptions and how to address any differences or concerns that arise in interactions

Eucrite Impact Melt NWA 5218 - Evidence for a Large Crater on Vesta

Northwest Africa (NWA) 5218 is a 76 g achondrite that is classified as a eucrite [1]. However, an initial classification [2] describes it as a "eucrite shock-melt breccia...(in which) large, partially melted cumulate basalt clasts are set in a shock melt flow...". We explore the petrology of this clast-bearing impact melt rock (Fig. 1), which could be a characteristic lithology at large impact craters on asteroid Vesta [3]. Methods: Optical microscopy, scanning electronmicroscopy, and Raman spectroscopy were used on a thin section (Fig. 1) for petrographic characterization. The impact melt composition was determined by 20 m diameter defocused-beam analyses with a Cameca SX-100 electron microprobe. The data from 97 spots were corrected for mineral density effects [4]. Constituent mineral phases were analyzed with a focusedbeam. Bidirectonal visible and near-infrared (VNIR) and biconical FT-IR reflectance spectra were measured on the surface of a sample slab on its central melt area and on an eucrite clast, and from 125-500 m and 100 m are coarse-grained with equigranular ~1 mm size plagioclase, quartz, and clinopyroxene (Fig. 1). Single crystals of chromite, ilmenite, zircon, Ca-Mg phosphate, Fe-metal, and troilite are embedded in the melt. Polymineralic clasts are mostly compositionally similar to the above mentioned larger clasts but scarce granulitic fragments are observed as well

Can Anyone Hear Us? An Exploration of Echo Chambers at a Land-Grant University

Faculty at land-grant universities are expected to engage in some form of Extension, or science communication, as part of the land-grant mission. However, critics have claimed these institutions are out of touch with their stakeholders’ needs and faculty mainly communicate with others in academia. This engagement with a homogenous group reflects the concepts of echo chambers, where people are only exposed to information that aligns with their beliefs and current knowledge and discredit opposing information. An explanatory mixed-methods design was used to understand land-grant faculty’s engagement in echo chambers. A survey was distributed to a census of tenure-track faculty in the University of Florida’s Institute of Food and Agricultural Sciences to understand respondents’ engagement in echo chambers. Follow-up interviews were conducted with 13 of the survey respondents to further explore their audiences and channels used in science communication to understand their engagement in echo chambers. Survey results indicated faculty did not necessarily participate in echo chambers, but they also did not contribute to an open communication network. However, the interviews found participants were interested in reaching new audiences yet struggled to communicate with stakeholders. The participants also reported wanting to find alternative channels to peer reviewed journals to help disseminate their work. The findings from this study indicated faculty contributed to a type of echo chamber, but rather than viewing their stakeholders’ opinions as false, they simply did not hear the opinions. Agricultural communicators should work with land-grant faculty administrators to identify appropriate audiences and channels for science communication

The JCMT Gould Belt Survey: Evidence for radiative heating in Serpens MWC 297 and its influence on local star formation

We present SCUBA-2 450micron and 850micron observations of the Serpens MWC 297 region, part of the JCMT Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star-formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two component model of the JCMT beam for a fixed dust opacity spectral index of beta = 1.8. Within 40 of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free-free emission with a spectral index of 1.03+-0.02, consistent with an ultra-compact HII region and polar winds/jets. Contamination accounts for 73+-5 per cent and 82+-4 per cent of peak flux at 450micron and 850micron respectively. The residual thermal disk of the star is almost undetectable at these wavelengths. Young Stellar Objects are confirmed where SCUBA-2 850micron clumps identified by the fellwalker algorithm coincide with Spitzer Gould Belt Survey detections. We identify 23 objects and use Tbol to classify nine YSOs with masses 0.09 to 5.1 Msun. We find two Class 0, one Class 0/I, three Class I and three Class II sources. The mean temperature is 15+-2K for the nine YSOs and 32+-4K for the 14 starless clumps. We observe a starless clump with an abnormally high mean temperature of 46+-2K and conclude that it is radiatively heated by the star MWC 297. Jeans stability provides evidence that radiative heating by the star MWC 297 may be suppressing clump collapse.Comment: 24 pages, 13 figures, 7 table

The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

We present 850 and 450 μm observations of the dense regions within the Auriga–California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHα 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 μm emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga–Cal. We find that the disparity between the richness of infrared star-forming objects in Orion A and the sparsity in Auriga–Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga–Cal will maintain a lower star formation efficiency

Triple oxygen isotopic composition of the high-³He/⁴He mantle

Measurements of Xe isotope ratios in ocean island basalts (OIB) suggest that Earth’s mantle accreted heterogeneously, and that compositional remnants of accretion are sampled by modern, high-3He/4He OIB associated with the Icelandic and Samoan plumes. If so, the high-3He/4He source may also have a distinct oxygen isotopic composition from the rest of the mantle. Here, we test if the major elements of the high-3He/4He source preserve any evidence of heterogeneous accretion using measurements of three oxygen isotopes on olivine from a variety of high-3He/4He OIB locations. To high precision, the Δ17O value of high-3He/4He olivines from Hawaii, Pitcairn, Baffin Island and Samoa, are indistinguishable from bulk mantle olivine (Δ17OBulk Mantle − Δ17OHigh 3He/4He olivine = −0.002 ± 0.004 (2 × SEM)‰). Thus, there is no resolvable oxygen isotope evidence for heterogeneous accretion in the high-3He/4He source. Modelling of mixing processes indicates that if an early-forming, oxygen-isotope distinct mantle did exist, either the anomaly was extremely small, or the anomaly was homogenised away by later mantle convection. The δ18O values of olivine with the highest 3He/4He ratios from a variety of OIB locations have a relatively uniform composition (∼5‰). This composition is intermediate to values associated with the depleted MORB mantle and the average mantle. Similarly, δ18O values of olivine from high-3He/4He OIB correlate with radiogenic isotope ratios of He, Sr, and Nd. Combined, this suggests that magmatic oxygen is sourced from the same mantle as other, more incompatible elements and that the intermediate δ18O value is a feature of the high-3He/4He mantle source. The processes responsible for the δ18O signature of high-3He/4He mantle are not certain, but δ18O–87Sr/86Sr correlations indicate that it may be connected to a predominance of a HIMU-like (high U/Pb) component or other moderate δ18O components recycled into the high-3He/4He source