@article{SoutoVeigaGroeneveldEnrightetal.2022,
  author    = {Souto-Veiga, Rodrigo and Groeneveld, Juergen and Enright, Neal J. and Fontaine, Joseph B. and Jeltsch, Florian},
  title     = {Declining pollination success reinforces negative climate and fire change impacts in a serotinous, fire-killed plant},
  series = {Plant ecology : an international journal},
  volume    = {223},
  journal   = {Plant ecology : an international journal},
  number    = {7},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1385-0237},
  doi       = {10.1007/s11258-022-01244-7},
  pages     = {863 -- 881},
  year      = {2022},
  abstract  = {Climate change projections predict that Mediterranean-type ecosystems (MTEs) are becoming hotter and drier and that fires will become more frequent and severe. While most plant species in these important biodiversity hotspots are adapted to hot, dry summers and recurrent fire, the Interval Squeeze framework suggests that reduced seed production (demographic shift), reduced seedling establishment after fire (post fire recruitment shift), and reduction in the time between successive fires (fire interval shift) will threaten fire killed species under climate change. One additional potential driver of accelerated species decline, however, has not been considered so far: the decrease in pollination success observed in many ecosystems worldwide has the potential to further reduce seed accumulation and thus population persistence also in these already threatened systems. Using the well-studied fire-killed and serotinous shrub species Banksia hookeriana as an example, we apply a new spatially implicit population simulation model to explore population dynamics under past (1988-2002) and current (2003-2017) climate conditions, deterministic and stochastic fire regimes, and alternative scenarios of pollination decline. Overall, model results suggest that while B. hookeriana populations were stable under past climate conditions, they will not continue to persist under current (and prospective future) climate. Negative effects of climatic changes and more frequent fires are reinforced by the measured decline in seed set leading to further reduction in the mean persistence time by 12-17\%. These findings clearly indicate that declining pollination rates can be a critical factor that increases further the pressure on the persistence of fire-killed plants. Future research needs to investigate whether other fire-killed species are similarly threatened, and if local population extinction may be compensated by recolonization events, facilitating persistence in spatially structured meta-communities.},
  language  = {en}
}
@article{LachmuthHenrichmannHornetal.2017,
  author    = {Lachmuth, Susanne and Henrichmann, Colette and Horn, Juliane and Pagel, J{\"o}rn and Schurr, Frank M.},
  title     = {Neighbourhood effects on plant reproduction},
  series = {The journal of ecology},
  volume    = {106},
  journal   = {The journal of ecology},
  number    = {2},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0022-0477},
  doi       = {10.1111/1365-2745.12816},
  pages     = {761 -- 773},
  year      = {2017},
  abstract  = {Density dependence is of fundamental importance for population and range dynamics. Density-dependent reproduction of plants arises from competitive and facilitative plant-plant interactions that can be pollination independent or pollination mediated. In small and sparse populations, conspecific density dependence often turns from negative to positive and causes Allee effects. Reproduction may also increase with heterospecific density (community-level Allee effect), but the underlying mechanisms are poorly understood and the consequences for community dynamics can be complex. Allee effects have crucial consequences for the conservation of declining species, but also the dynamics of range edge populations. In invasive species, Allee effects may slow or stop range expansion. Observational studies in natural plant communities cannot distinguish whether reproduction is limited by pollination-mediated interactions among plants or by other neighbourhood effects (e.g. competition for abiotic resources). Even experimental pollen supply cannot distinguish whether variation in reproduction is caused by direct density effects or by plant traits correlated with density. Finally, it is unknown over which spatial scales pollination-mediated interactions occur. To circumvent these problems, we introduce a comprehensive experimental and analytical framework which simultaneously (1) manipulates pollen availability and quality by hand pollination and pollinator exclusion, (2) manipulates neighbourhoods by transplanting target plants, and (3) analyses the effects of con- and heterospecific neighbourhoods on reproduction with spatially explicit trait-based neighbourhood models. Synthesis. By manipulating both pollen availability and target plant locations within neighbourhoods, we can comprehensively analyse spatially explicit density dependence of plant reproduction. This experimental approach enhances our ability to understand the dynamics of sparse populations and of species geographical ranges.},
  language  = {en}
}
@article{HobbhahnKuechmeisterPorembski2006,
  author    = {Hobbhahn, Nina and K{\"u}chmeister, Heike and Porembski, Stefan},
  title     = {Pollination biology of mass flowering terrestrial Utricularia species (Lentibulariaceae) in the Indian Western Ghats},
  series = {Plant biology},
  volume    = {8},
  journal   = {Plant biology},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Oxford},
  issn      = {1435-8603},
  doi       = {10.1055/s-2006-924566},
  pages     = {791 -- 804},
  year      = {2006},
  abstract  = {The pollination biology of three mass flowering Utricularia species of the Indian Western Ghats, U. albocaerulea, U. purpurascens, and U. reticulata, was studied for the first time by extensive observation of flower visitors, pollination experiments, and nectar analyses. The ephemerality of the Utricularia habitats on lateritic plateaus, weather conditions adverse to insects, lack of observations of flower visitors to other Utricularia spp., and the predominance of at least. facultative autogamy in the few Utricularia species studied so far suggested that an autogamous breeding system is the common case in the genus. In contrast, we showed that the studied populations are incapable of autonomous selfing, or that it is an event of negligible rarity, although P/O was similarily low as in autogamous species investigated by other authors. In all three species the spatial arrangement of the reproductive organs makes an insect vector necessary for pollen transfer between and within flowers. However, U. purpurascens and U. reticulata are highly self-compatible, which allows for visitor-mediated auto-selfing and geitonogamy on inflorescence and clone level. Floral nectar is present in extremely small volumes in all three species, but sugar concentrations are high. More than 50 species of bees, butterflies, moths, hawk moths, and clipterans were observed to visit the flowers, and flower morphology facilitated pollination by all observed visitors. The results are discussed in the context of the phenological characteristics of the studied species, especially the phenomenon of mass flowering, and the environmental conditions of their habitats.},
  language  = {en}
}