Maria Paniw

Interacting livestock and fire may both threaten and increase viability of a fire‐adapted Mediterranean carnivorous plant

1. Quantifying interactive effects of environmental drivers on population dynamics can be critical for a robust analysis of population viability. Fire regimes, among the most widespread disturbances driving population dynamics, are increasingly modified by and interact with human activities. However, viability of fire-adapted species is typically assessed overlooking disturbance interactions, potentially resulting in suboptimal management actions.

Effects of extreme rainfall events on the distribution of selected emerging contaminants in surface and groundwater: The Guadalete River basin (SW, Spain)

This study is focused on the Guadalete River basin (SW, Spain), where extreme weather conditions have become common, with and alternation between periods of drought and extreme rainfall events. Combined sewer overflows (CSOs) occur when heavy rainfall events exceed the capacity of the wastewater treatment plants (WWTP), as well as pollution episodes in parts of the basin due to uncontrolled sewage spills and the use of reclaimed water and sludge from the local WWTP. The sampling was carried out along two seasons and three campaigns during dry (March 2007) and extreme rainfall (April and December 2010) in the Guadalete River, alluvial aquifer and Jerez de la Frontera aquifer. Results showed minimum concentrations for synthetic surfactants in groundwater (<37.4μg·L-1) during the first campaign (dry weather conditions), whereas groundwater contaminants increased in December 2010 as the heavy rainfall caused the river to overflow. In surface water, surfactant concentrations showed similar trends to groundwater observations. In addition to surfactants, pharmaceuticals and personal care products (PPCPs) were analyzed in the third campaign, 22 of which were detected in surface waters. Two fragrances (OTNE and galaxolide) and one analgesic/anti-inflammatory (ibuprofen) were the most abundant PPCPs (up to 6540, 2748 and 1747ng·L-1, respectively). Regarding groundwater, most PPCPs were detected in Jerez de la Frontera aquifer, where a synthetic fragrance (OTNE) was predominant (up to 1285ng·L-1).

Interactive life-history traits predict sensitivity of plants and animals to temporal autocorrelation

Temporal autocorrelation in demographic processes is an important aspect of population dynamics, but a comprehensive examination of its effects on different life-history strategies is lacking. We use matrix population models from 454 plant and animal populations to simulate stochastic population growth rates (log λs ) under different temporal autocorrelations in demographic rates, using simulated and observed covariation among rates. We then test for differences in sensitivities, or changes of log λs to changes in autocorrelation among two major axes of life-history strategies, obtained from phylogenetically informed principal component analysis: the fast-slow and reproductive-strategy continua. Fast life histories exhibit highest sensitivities to simulated autocorrelation in demographic rates across reproductive strategies. Slow life histories are less sensitive to temporal autocorrelation, but their sensitivities increase among highly iteroparous species. We provide cross-taxonomic evidence that changes in the autocorrelation of environmental variation may affect a wide range of species, depending on complex interactions of life-history strategies.

Defining the role of fire in alleviating seed dormancy in a rare Mediterranean endemic subshrub

Our study provides a foundational understanding of seed ecology and germination biology in the threatened Mediterranean-endemic carnivorous plant Drosophyllum lusitanicum, with data implicating fire-related cues as a significant ecological mechanism influencing recruitment. Seeds are physiologically dormant at release and germinate rapidly after exposure to short pulses of temperatures similar to those experienced in soils during the passage of fire (80-100°C). Understanding the ecological requirements of rare and threatened species such as D. lusitanicum is critical to the implementation of effective conservation initiatives, and an accurate understanding of their reproductive mechanisms dramatically increases the likelihood of such actions to succeed.

Attract them anyway: benefits of large, showy flowers in a highly autogamous, carnivorous plant species.

Despite being a highly autogamous or self-pollinating species, the carnivorous plant Drosophyllum lusitanicum (Drosophyllaceae) produces large, bright-yellow flowers. Our results detected a significant increase (15-25%) in seed set of experimentally self-pollinated flowers and flowers exposed to insect visitation compared with bagged, untouched flowers whose seeds were produced only by spontaneous self-pollination. Given that the key life-history stage of this fire-adapted plant species is the formation of a persistent seed-bank, any increase in seed production through insect pollinator activity would increase plant fitness. This in turn would explain the maintenance of large, showy flowers in a highly autogamous plant.

Effective prey attraction in the rare Drosophyllum lusitanicum, a flypaper-trap carnivorous plant

PREMISE OF THE STUDYnCarnivorous plants have unusually modified leaves to trap insects as an adaptation to low-nutrient environments. Disparate mechanisms have been suggested as luring traits to attract prey insects into their deadly leaves, ranging from very elaborate to none at all. Drosophyllum lusitanicum is a rare carnivorous plant with a common flypaper-trap mechanism. Here we tested whether Drosophyllum plants lure prey insects into their leaves or they act just as passive traps.nnnMETHODSnWe compared prey capture between live, potted plants and Drosophyllum-shaped artificial mimics coated with odorless glue. Since this species is insect-pollinated, we also explored the possible existence of a pollinator-prey conflict by quantifying the similarity between the pollination and prey guilds in a natural population. All experiments were done in southern Spain.nnnKEY RESULTSnThe sticky leaves of Drosophyllum captured significantly more prey than mimics, particularly small dipterans. Prey attraction, likely exerted by scent or visual cues, seems to be unrelated to pollinator attraction by flowers, as inferred from the low similarity between pollinator and prey insect faunas found in this species.nnnCONCLUSIONSnOur results illustrate the effectiveness of this carnivorous species at attracting insects to their flypaper-trap leaves.

Transient facilitation of resprouting shrubs in fire-prone habitats

Aims Fires play a crucial role mediating species interactions in the Mediterranean Basin, with one prominent example being the nursing effect of post‐fire resprouting shrubs on tree recruits, which then outcompete their benefactors throughout succession. Yet, the community structuring role of resprouting shrubs as potential facilitators of post‐fire recruiting subshrub species, which are commonly outcompeted in late post‐fire stages, has been overlooked. The aims of this work were to investigate (i) whether proximity to resprouting shrubs increased the demographic performance of a fire‐adapted carnivorous subshrub and (ii) whether mature shrubs negatively affected the performance of established plants through interference with prey capture. Methods To evaluate the facilitative effects of resprouting shrubs, we sowed seeds of Drosophyllum lusitanicum, a carnivorous, seeder pyrophyte, into two microhabitats in recently burned heathland patches defined by proximity to resprouting shrubs. We monitored key demographic rates of emerged seedlings for 2 years. To test for competitive effects of shrubs on plant performance at a later habitat regeneration stage, we placed greenhouse‐reared, potted plants into distinct microhabitats in neighboring burned and unburned heathland patches and monitored prey capture. Both experiments were performed in the Aljibe Mountains at the Northern Strait of Gibraltar and were replicated in 2 years. Important Findings Resprouting shrubs significantly improved survival, juvenile size and flowering probability compared with open microhabitats, and had no significantly negative effects on the growth of recruits. Prey capture was significantly lower in unburned heathland patches compared with burned ones, thus partly explaining the decrease in survival of Drosophyllum individuals in mature heathlands. However, microhabitat did not affect prey capture. Our findings suggest that not only periodic fires, removing biomass in mature stands, but also resprouting neighbors, increasing establishment success after fire, may be important for the viability of early successional pyrophytes.

Plant carnivory beyond bogs: reliance on prey feeding in Drosophyllum lusitanicum (Drosophyllaceae) in dry Mediterranean heathland habitats

Background and AimsnIn a cost-benefit framework, plant carnivory is hypothesized to be an adaptation to nutrient-poor soils in sunny, wetland habitats. However, apparent exceptions to this cost-benefit model exist, although they have been rarely studied. One of these exceptions is the carnivorous subshrub Drosophyllum lusitanicum , which thrives in Mediterranean heathlands on dry sandstone soils and has relatively well-developed, xeromorphic roots. Here, the roles of leaf (carnivory) and root (soil) nutrient uptake in growth promotion of this particular species were assessed.nnnMethodsnIn a greenhouse experiment, plants were fed with laboratory-reared fruit flies ( Drosophila virilis ) and received two concentrations of soil nutrients in a factorial design. Above-ground plant growth and final above- and below-ground dry biomass after 13xa0weeks were recorded. Nutrient uptake via roots was also evaluated, using stable nitrogen isotope analysis.nnnKey ResultsnInsect feeding resulted in significantly higher growth and above- and below-ground biomass compared with soil fertilization. No additional benefits of fertilization were discernable when plants were insect-fed, indicating that roots were not efficient in nutrient absorption.nnnConclusionsnThe first evidence of strong reliance on insect prey feeding in a dry-soil carnivorous plant with well-developed roots is provided, suggesting that carnivory per se does not preclude persistence in dry habitats. Instead, the combination of carnivory and xeromorphic root features allows Drosophyllum to thrive on non-waterlogged soils. New evidence is added to recent research emphasizing the role of root systems of carnivorous plants in explaining their distribution, partly challenging the cost-benefit hypothesis.

Removal of pharmaceuticals in urban wastewater: High rate algae pond (HRAP) based technologies as an alternative to activated sludge based processes

Microalgae biotechnology is a promising tool for many applications, including the elimination of nutrients and other contaminants from wastewater. In this work, we measured the removal efficiency of two wastewater treatment processes: an activated-sludge based conventional process and another based on microalgae biotechnology using high-rate algae ponds (HRAPs). The latter was tested using two different configurations. In the first one, HRAPs were placed after an UASB reactor and used as a tertiary treatment to remove nutrients. In the second, the UASB reactor was disconnected so the HRAPs were directly fed with pretreated wastewater. Additional treatment was performed using dissolved air flotation (DAF). The performances of both configurations (UASB-HRAP and HRAP-DAF) were compared to that of the conventional line including primary and secondary biological treatments and operating in parallel within the same wastewater treatment plant (WWTP). Sixty-four out of 81 target PhACs were detected in the influent of the WWTP, at an average concentration of 223u202fμgu202fL-1, whereas 55 and 54 were measured in the conventional (14u202fμgu202fL-1) and non-conventional (17u202fμgu202fL-1) effluents. Average removal efficiencies were similar (94 vs. 92%) for both treatment lines when comparing total PhACs concentrations. The compositional patterns of the resulting effluents, however, were not, suggesting the occurrence of differential removal mechanisms depending on the chemicals and wastewater treatments considered. Highly consumed compounds such as ibuprofen and acetaminophen were predominant in the non-conventional effluent (>1u202fμgu202fL-1), denoting lower removal than in the conventional line. On the other hand, elimination of diclofenac and some specific antibiotics and diuretics (e.g., hydrochlorothiazide) was between 15 and 50% higher using HRAPs. Overall, the efficiency of the microalgae technology removing PhACs was found to be comparable to that used in conventional WWTPs. This, combined with a higher efficiency removing nutrients, shows the potential of HRAP technology for wastewater treatment as an alternative (or addition as tertiary treatment) to more conventional approaches based on activated sludge.

Perspectives from animal demography on incorporating evolutionary mechanism into plant population dynamics

With a growing number of long-term, individual-based data on natural populations available, it has become increasingly evident that environmental change affects populations through complex, simultaneously occurring demographic and evolutionary processes. Analyses of population-level responses to environmental change must therefore integrate demography and evolution into one coherent framework. Integral projection models (IPMs), which can relate genetic and phenotypic traits to demographic and population-level processes, offer a powerful approach for such integration. However, a rather artificial divide exists in how plant and animal population ecologists use IPMs. Here, I argue for the integration of the two sub-disciplines, particularly focusing on how plant ecologists can diversify their toolset to investigate selection pressures and eco-evolutionary dynamics in plant population models. I provide an overview of approaches that have applied IPMs for eco-evolutionary studies and discuss a potential future research agenda for plant population ecologists. Given an impending extinction crisis, a holistic look at the interacting processes mediating population persistence under environmental change is urgently needed.