Pollination ecology of the New Zealand alpine flora

The interactions between flowers and the insects that pollinate them have fascinated scientists for more than 200 years. The last century saw the establishment of the fundamental concept of pollination syndromes which allows classification of flowers according to the agents that pollinate them demonstrating specialisation and co-evolution of plants and pollinators. This concept has recently been questioned and the contrary, ubiquitous generalisation and chance have been proposed to be the driving forces behind plant – pollinator interactions on an individual and community level. The present study was carried out to address the question of the level of pollinator dependence and generalisation in pollination systems in an alpine plant community in alpine New Zealand. Initial research in New Zealand alpine habitats had lead to the assumption of minor importance of insect pollination as the alpine flora in New Zealand in general is not very conspicuous and the available potential insect pollinators are mainly flies and short-tongued native bees. Therefore it had been proposed that the level of autogamy and generalisation in pollination interactions in a high-alpine habitat should be high. However, it could be demonstrated that the majority of the 23 plant species in the alpine community depend on pollinator service to achieve reproductive success. A total of 87% of plant species under investigation are at least in part self-incompatible and therefore rely on pollinator service for outcross-pollen delivery. Moreover, it could be shown that the pollinators that transfer pollen do not choose plants at random. The pollination systems in the alpine community proved to consist of both rather specialised and rather generalised functional pollinator groups, moths and native bees belonging to the former and syrphid flies belonging to the latter. Furthermore, there was strong evidence that flower visitors do not automatically equal pollinators and that pollination efficiency differed between functional groups. When assessing the floral cues, e.g. flower colour and scent that attract a certain functional pollinator group, no clustering of the attractants in correlation with pollinator group could be demonstrated. However, the individual combination of colour and scent rendered each plant species distinct from most others. This novel feature of the alpine plant community may be interpreted as a way to facilitate associative pollinator learning. A foraging pollinator can easily memorise distinct flowers and subsequently proceed to direct visitation to repeat the experience of rewards. This way flower constancy and increased efficiency of pollen transfer is promoted allowing plants to benefit from adequate pollen delivery and xenogamous reproduction resulting in genetically diverse progeny that has a greater potential of survival in the challenging alpine environment

Valuing Biodiversity in Life Cycle Impact Assessment

Erratum published on 13 March 2020, see Sustainability 2020, 12(6), 2270. https://doi.org/10.3390/su11205628In this article, the authors propose an impact assessment method for life cycle assessment (LCA) that adheres to established LCA principles for land use-related impact assessment, bridges current research gaps and addresses the requirements of different stakeholders for a methodological framework. The conservation of biodiversity is a priority for humanity, as expressed in the framework of the Sustainable Development Goals (SDGs). Addressing biodiversity across value chains is a key challenge for enabling sustainable production pathways. Life cycle assessment is a standardised approach to assess and compare environmental impacts of products along their value chains. The impact assessment method presented in this article allows the quantification of the impact of land-using production processes on biodiversity for several broad land use classes. It provides a calculation framework with degrees of customisation (e.g., to take into account regional conservation priorities), but also offers a default valuation of biodiversity based on naturalness. The applicability of the method is demonstrated through an example of a consumer product. The main strength of the approach is that it yields highly aggregated information on the biodiversity impacts of products, enabling biodiversity-conscious decisions about raw materials, production routes and end user products

Die Ökobilanz als Instrument für informierte Konsumentscheidungen - bewusster Konsum kann Biodiversität schützen

Eine der größten globalen Herausforderungen ist aktuell der Schutz und die Erhaltung von Biodiversität. Dabei stellt der Konsum von Gütern und Dienstleistungen einen zentralen Risikofaktor für Biodiversität und Ökosystemleistungen dar. Biodiversität ist eine komplexe Größe, die sich über die Vielfalt der Arten, die Vielfalt der Lebensräume und die genetische Vielfalt innerhalb der Organismen definiert. Zur Risikoabschätzung bedarf es einer möglichst genauen Erfassung, die sich aufgrund der inhärenten Komplexität jedoch oftmals schwierig gestaltet. Welche Möglichkeiten für biodiversitäts-bewussten Konsum gibt es aktuell? Grundsätzlich können die Auswirkungen von Produkten und Produktionsprozessen auf die Umwelt in Ökobilanzen analysiert werden. Wir schlagen für das Instrument der Ökobilanz eine anwenderfreundliche Methode zur Bewertung von Biodiversität vor. Diese beruht auf der Erfassung der Veränderung der Qualität einer bestimmten Fläche über einen bestimmten Zeitraum, die durch die Herstellung eines bestimmten Produkts verursacht wird. In angemessener Form kommuniziert können Ökobilanzergebnisse dazu beitragen, Konsum durch gezielte Information bewusster und damit potenziell nachhaltiger zu gestalten

Floral scent in natural hybrids of Ipomopsis (Polemoniaceae) and their parental species

Background and aimsFloral traits, such as floral volatiles, can contribute to pre-zygotic reproductive isolation by promoting species-specific pollinator foraging. When hybrid zones form, floral traits could also influence post-zygotic isolation. This study examined floral volatiles in parental species and natural hybrids in order to explore potential scent mediation of pre-zygotic and post-zygotic isolation.MethodsFloral bouquets were analysed for the sister species Ipomopsis aggregata and I. tenuituba and their natural hybrids at two contact sites differing in both hybridization rate and temporal foraging pattern of hawkmoth pollinators. Floral volatiles were quantified in diurnal and nocturnal scent samples using gas chromatography-mass spectrometry.Key resultsThe bouquets of parental species and hybrids showed qualitative overlap. All flowers emitted similar sets of monoterpenoid, sesquiterpenoid, aliphatic and benzenoid compounds, but separated into groups defined by multivariate analysis of quantitative emissions. The parental species differed most strikingly in the nitrogenous compound indole, which was found almost exclusively in nocturnal bouquets of I. tenuituba. Natural hybrid bouquets were highly variable, and showed emission rates of several compounds that appeared transgressive. However, indole emission rates were intermediate in the hybrids compared with rates in the parents. Volatile bouquets at the contact site with lower hybridization did not show greater species specificity in overall scent emission, but I. tenuituba presented a stronger indole signal during peak hawkmoth activity at that site.ConclusionsThe two species of Ipomopsis differed in patterns of floral bouquets, with indole emitted in nocturnal I. tenuituba, but not in I. aggregata. Natural hybrid bouquets were not consistently intermediate between the parents, although hybrids were intermediate in indole emission. The indole signal could potentially serve as a hawkmoth attractant that mediates reproductive isolation both before and after hybrid formation

Data from: Context-dependent reproductive isolation mediated by floral scent and color

Reproductive isolation due to pollinator behavior is considered a key mode of speciation in flowering plants. Although floral scent is thought to mediate pollinator behavior, little is known about its effects on pollinator attraction and floral visitation in the wild. We used field experiments with wild hawkmoths and laboratory experiments with naïve hawkmoths to investigate attraction to and probing of flowers in response to indole, a volatile emitted by Ipomopsis tenuituba but not its close relative I. aggregata, both alone and in combination with floral color differences. We demonstrated that indole attracts wild hawkmoths to flowers, but has little effect on the rate at which those attracted moths probe flowers. In contrast, white flower color did not influence hawkmoth attraction in the field, but caused more attracted moths to probe flowers. Thus the moths require both scent and high visual contrast, in that order, to feed at flowers at dusk. Their preference for indole-scented flowers is innate, but species-specific preference is mitigated by previous experience and plant spatial patterning. This context-dependent behavior helps explain why these Ipomopsis species show geographical variation in the extent of hybridization and may potentially explain formation of hybrid bridges in other systems of hawkmoth-pollinated plants