1,720,997 research outputs found
Lampenflora growth-control: the challenge of the show caves
No full textShow caves are subjected to tourist adaptations, often with negative consequences on the ecological
equilibria of the system. Among the worst problems, photosynthetic biofilms, called “lampenflora”, can
develop on surfaces due to the artificial lighting system, covering with green patinas every lit rocks,
included speleothems, such as the still few known vermiculations. They implement biodeteriorations
processes on surfaces, damaging them irreversibly. The aim of this study was to investigate the efficacy of
lampenflora growth-control strategies, carried out monthly using chemical (15% hydrogen peroxide2 or
commercial bleach) and physical (UV-C) remedies, on surfaces with and without vermiculations. The tests
were performed in the tourist trail of the Pertosa-Auletta Cave (southern Italy), lit and frequented by
human beings, analyzing, before and after the treatments, the chlorophyll fluorescences (MINI-PAM, Walz),
an in situ non-destructive method representing a proxy of the biofilms photosynthetic activities. The results
highlighted an evident reduction of the lampenflora photosynthetic activity already after the 1st treatment.
Before every actions, the dark-adapted surfaces, with and without vermiculations, displayed Fv/Fm values
between 0.766-0.713 and 0.710-0.663, respectively. After chemical treatments, using H2O2 or commercial
bleach, the maximal PSII photochemical efficiency was close to 0, showing an almost complete reduction of
the photosynthetic activity. Such values have been maintained until the 2nd treatment, in pre- and post
phase. After three months without treatments due to the pandemic lockdown closure of the show cave,
there was a slight recovery of lampenflora on the surfaces treated with H2O2, immediately stopped after
the 3rd treatment. No effect occurred on the surfaces treated with UV-C, probably in relation to the low
frequency of treatments (one night) in a month
Underground ecosystem conservation through high-resolution air monitoring
Full text linkIn cave ecosystems tourists represent moving sources of discontinuous disturbances, able to induce transient system responses whose knowledge is crucial in defining appropriate conservation measures. Here we propose an approach to evaluate the amplitude and scales of cave alterations based on high-resolution air monitoring, through the use of purposely developed low-cost monitoring stations and a consistent analytical framework for information retrieval based on time series analysis. In particular, monitoring stations adopt a modular structure based on physical computing platforms acquiring data through several sensors, with means of preventing humidity damages and guaranteeing their continuous operation. Data are then analyzed using wavelet periodograms and cross-periodograms to extract the scales of tourism-induced alterations. The approach has been exemplified in the Pertosa-Auletta Cave, one of the most important underground environments in Southern Italy, highlighting the development of monitoring stations and the information obtainable with the proposed analytical workflow. Here, 2 monitoring stations acquiring data for 1 year at 1′ sampling time on temperature, relative humidity, CO2, VOCs, and particulate matter were deployed in trails subjected to different levels of tourism. In terms of Pertosa-Auletta Cave air dynamics, the approach allowed estimating the temporal and spatial scales of tourism-induced alterations in the order of minutes and meters, respectively, with parameter-dependent variations. On more general terms, the approach proved reliable and effective, with its modularity and low-cost fostering its straightforward adoption in other underground ecosystems, where it can support the development of tailored management strategies
Geochemical characterization of clastic sediments sheds light on energy sources and on alleged anthropogenic impacts in cave ecosystems
No full textRhizosheath: Roles, Formation Processes and Investigation Methods
Full text linkClimate change negatively affects crop productivity, threatening the survival of entire populations from many vulnerable hotspot regions of the world with the risk of exacerbating hunger, malnutrition and international inequality. Selecting plant species manifesting abiotic stress-tolerant adaptive traits represents a challenge towards ensuring that crops are more resistant and resilient to environmental perturbations. The rhizosheath, defined as the complex of root hair, exudates and soil that strongly adheres to plant roots, is a promising root adaptive trait in facing conditions of water and nutrient deficits, as well as acidic soil. Several beneficial ecological functions are attributed to the rhizosheath, such as enhancing water and nutrient uptake; protecting from dehydration, heat and acid stresses; and stimulating microbial activities. It has been described in several Angiosperm species, including crops grown in severe habitats. The aim of this review was to collect the relevant literature produced to date regarding rhizosheaths, focusing on (i) the various processes involved in its formation, including both physicochemical and biological ones; (ii) the evolutionary and ecological role of rhizosheaths; and (iii) the most frequently used methodologies for its investigation and characterization. The present work provides a comprehensive overview of this revolutionary root’s great agronomic importance in order to address future research aiming to fill the existing knowledge gaps and define a common and shared methodology
Sustainable Tourism and Conservation of Underground Ecosystems through Airflow and Particle Distribution Modeling
No full textUnderground ecosystems are often of interest for the tourism industry due to their important naturalistic and cultural heritage. Since these underground ecosystems are almost completely isolated, external agents (such as human presence) can easily disrupt their chemico-physical and biological processes, which can affect, sometimes irrevocably, their natural equilibrium, placing the preservation of such sites at risk. The most sensible managers of caves, catacombs, mines, and all the accessible cultural sites are searching for methods to control these dynamics and the modeling appears to be effective in preventing scenarios of the known impacts as well as suggesting strategies for their mitigation. In this study, by employing finite element analysis by the COMSOL Multiphysics software and reproducing, in a simplified way, a section of the tourist trail of the Pertosa-Auletta Cave (Italy), for the first time we provided a fact-finding survey of the airflow and the scattering and subsequent deposition of particles transported by tourists. Taking into account discontinuities in the pathway, the simulations rebuilt the possible natural airflow line, reproducing the particle movements induced by different tourist loads, whose high numbers increase the swirling movement of air masses, promoting a higher dispersion of particles, even in the remote cave areas. Performed simulations clearly indicated both the speed and direction followed by particles, as well as deposition sites, highlighting potential hotspots of damage, and demonstrating that the employed approach can be an excellent tool for planning the management of these extraordinary ecosystems, foretelling anthropogenic impacts, and supporting managers in decision-making processes
High-resolution atmospheric monitoring in cave ecosystems: dynamics, impacts and implications for management and conservation
No full textThe adoption of data-driven policies is increasingly recognized as the gold standard in managing and preserving ecosystems and relies on effective means of continuously monitoring environmental dynamics. Such an approach is crucial wherever even light anthropogenic pressures are able to exert deep alterations, like in cave ecosystems, where tourism fruition introduces moving sources of discontinuous disturbances.
In this context, novel tools for high-resolution monitoring of cave atmosphere, coupling affordability and ease of construction with accuracy and adaptability to different requirements/environments, were developed. The approach pivots on low-cost and modular monitoring stations, organized into networks, providing high resolution data on several atmospheric parameters, and on an analytical workflow able to extract information on the temporal and spatial scales of tourist-induced alterations. The system can be also invaluable in shedding light on the natural dynamics of these peculiar environments, still scarcely understood, as we demonstrated in the Pertosa-Auletta Cave, one of the most important karst systems of southern Italy. In particular, the monitoring system allowed understanding the annual dynamics of temperature, relative humidity, CO2, VOC, and particulate matter size and concentration, evaluating their alterations induced by tourists and identifying the spatial and temporal scales of the latter.
On the one hand, findings shed novel light on the dynamics of this peculiar system, on the other hand, the simplicity, low-cost and effectiveness of the approach make it straightforwardly applicable to other underground ecosystems, where it can support the adoption of tailored management strategies
New insights on the ecology of underground ecosystems toward a sustainable management strategy
Full text link2020 - 2021Underground cavities represent some of the less explored places on the planet (Lee et
al., 2012). In fact, excluding the known carbonate dissolution/precipitation processes,
leading to the formation of holes in the host rock, as well as speleothems, little is known
about the ecology of these fascinating and enigmatic ecosystems. In spite of this, caves
are generally object of tourist adaptations, which can activate an irreversible impairment
of the biogeochemical equilibria, whose load, until now, is not estimated accurately, due
to the scanty information in this regard (Chiesi and Badino, 2008).
The anthropogenic effects on the air compartment represent the most indiscernible and
not immediately recognizable alteration, just thinking to the heat or breathing produced
by human body, influencing the natural temperature, relative humidity and CO2
concentrations. Moreover, visitors can be carriers of inorganic and organic matter (dust,
hair, bacteria, seeds…) constituting an important energy input, as well as a trophic
source, in the cave oligotrophic ecosystem, affecting its natural energy regime (Russell
and MacLean, 2008; Jurado et al., 2008; Smith et al., 2013; Bruno et al., 2014).
These factors are able to influence the reactions at the interface between the atmosphere
and the other compartments (lithosphere, hydrosphere and biota), fundamental in
controlling the ecosystem processes, that ensure the functioning of the whole
underground ecosystem (Pulido-Bosch et al., 1997; Milanolo and Gabrovšek, 2009; de
Freitas, 2010; Lang et al., 2015a; Lang et al., 2015b; Howarth, 2019). Hence, the
necessity to develop new, sturdy and low-cost tools, including also sensors for data
acquisition and modelling applications (Bugmann et al., 2000; Schmolke et al., 2010),
to monitor and assess continuously cave atmosphere, providing to the authority valid
and efficient devices helping them in the sustainable management. [preface edited by Author]XXXIV cicl
Cave vermiculations and microbiota, an ecological journey
No full textCaves constitute fascinating ecological niches for microorganisms, among which the
chemolithoautotrophic constitute the main primary producers of these ecosystems. The role of cave
microbiota in the formation of speleothems and other structures like vermiculations is still debated.
Vermiculations are enigmatic deposits of incoherent particles, observable on walls and ceilings of
worldwide natural or artificial caves, varying in morphology, color and size. They teem with life and
represent interesting systems to understand the ecological role of biota in the cave ecosystem.
The aim of this study was to contribute to the understanding of vermiculation nature and of the
ecological interactions involved in their genesis and development. To this end, an integrated
approach including geochemical, microbiological and microscopic surveys, was applied on 11
vermiculation types from Pertosa-Auletta Cave (Campania, southern Italy), exhibiting an exceptional
diversity and abundance of these structures.
XRD analyses revealed that vermiculations are mainly composed of calcite, with variable fractions
of minor constituents like quartz, clay minerals, siderite and feldspars. Wide variations in Al, Ba, Ca,
Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, S, Si, Sr, Ti, V and Zn concentrations among vermiculations
were highlighted by elemental analysis, due to substrate characteristics and deposition of
exogenous inorganic and organic matter. 16S rRNA NGS survey showed that Proteobacteria (48.0%)
was the most abundant phylum in the Bacteria domain, followed by Acidobacteria (11.6%),
Actinobacteria (7.1%), Nitrospirae (5.8%), Firmicutes (4.3%), Planctomycetes (3.2%), Chloroflexi
(1.9%) and Gemmatimonadetes (1.1%). Archaea (0.1%) and a significant percentage of unclassified
microorganisms (13.1%) were also observed. FE-SEM and CLSM confirmed the presence of
microorganisms and of their activity, supporting the hypothesis of a direct involvement of
microorganisms in the development of vermiculations, through the production of organic matter,
precipitation of secondary minerals, sediment trapping and binding, etching or pitting of the host
rock
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