Spatial and Temporal Ecological Uniqueness of Andean Diatom Communities Are Correlated With Climate, Geodiversity and Long-Term Limnological Change

Benito, Xavier; Vilmi, Annika; Luethje, Melina; Carrevedo, María Laura; Lindholm, Marja; Fritz, Sherilyn C.

doi:10.3389/fevo.2020.00260

Cited by 18 publications

(12 citation statements)

References 90 publications

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“…the most representative ones. These taxa are indicative of a wide range of environmental conditions, related to pH and nutrients (Benito et al 2020). This is consistent with the most frequent species reported in this study.…”

Section: Diatom Composition In the Context Of Mountain And Remote Lakessupporting

confidence: 91%

“…Diatoms are considered one of the algal groups with the largest number of species. In addition, they have specialized response to the environment (Benito et al 2020), which is quantitatively expressed through the ecological optimum and tolerances. The optimum is calculated as the weighted average of the abundance of a species with respect to a variable; the tolerance is calculated as the standard deviation.…”

Section: Aquatic Sciencesmentioning

confidence: 99%

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Diatom response to environmental gradients in the high mountain lakes of the Colombia’s Eastern Range

Muñoz-López

Rivera

2021

Aquat Sci

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A survey of 60 high mountain lakes of Colombia’s Eastern Range was performed to evaluate the response of surface-sediment diatoms to environmental variables. In each one of these lakes, water samples were taken for physical and chemical characterization, and diatoms were collected from the superficial bottom sediment at the deepest part. Multivariate statistical analyses were made to determine the relationships between environmental and biological data, specifically which environmental variables explain the diatom distribution. For each of these significant environmental variables, optima and ecological tolerances were calculated using the weighted-average method, which allowed for the classification of the species according to their environmental preferences. The lakes showed a wide range of environmental gradients in variables such as pH, alkalinity, and nutrients. In addition, the depth of the lakes was a direct determinant of the light environment of the water column. A total of 339 diatom taxa were identified belonging mainly to the genera Eunotia and Pinnularia. Variables related to pH-alkalinity gradient, trophic condition (nitrates and phosphorus), and physical factors (radiation at the bottom) had a significant effect on diatom composition. Despite the fact that the total organic carbon environmental range was high, the effect of this variable on diatom species composition was not significant. In conclusion, the diatoms of the studied lakes showed a significant ecological relationship with environmental variables which are potentially important in environmental reconstruction. Diatoms in the study sites can provide useful and independent quantitative information to investigate the recent impacts of global change on tropical high mountain ecosystems.

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Section: Diatom Composition In the Context Of Mountain And Remote Lakessupporting

confidence: 91%

Section: Aquatic Sciencesmentioning

confidence: 99%

Diatom response to environmental gradients in the high mountain lakes of the Colombia’s Eastern Range

Muñoz-López

Rivera

2021

Aquat Sci

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“…Thus, we can conclude that the diatom communities in these lakes were generally resilient within their disturbance regimes—regardless of the nature and driver of that regime. Using a larger lake‐catchment database of modern and paleolimnological diatom samples, Benito et al (2020) showed that a combination of widespread climatic (i.e., Medieval Climate Anomaly) and local anthropogenic (historical human density) disturbances led to dynamically stable lake diatom assemblages by balancing increases and decreases of water conductivity and temperature seasonality. The existence of “good” modern analogues in the northern and central Andes (Fig.…”

Section: Discussionmentioning

confidence: 99%

Ecological resilience in tropical Andean lakes: A paleolimnological perspective

Benito

Luethje

Schneider

et al. 2021

Limnology & Oceanography

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Little is known about whether changes in lake ecosystem structure over the past 150 years are unprecedented when considering longer timescales. Similarly, research linking environmental stressors to lake ecological resilience has traditionally focused on a few sentinel sites, hindering the study of spatially synchronous changes across large areas. Here, we studied signatures of paleolimnological resilience by tracking change in diatom community composition over the last 2000 years in four Ecuadorian Andean lakes with contrasting ecoregions. We focused on climate and anthropogenic change, and the type of biological responses that these changes induced: gradual, elastic, or threshold. We combined multivariate ordination techniques with nonlinear time‐series methods (hierarchical generalized additive models) to characterize trajectories of community responses in each lake, and coherence in such trajectories across lakes. We hypothesized that remote, high‐elevation lakes would exhibit synchronous trends due to their shared climatic constraints, whereas lower elevation lakes would show less synchronous trends as a consequence of human density and land‐cover alteration. We found that gradual and elastic responses dominated. Threshold‐type responses, or regime shifts, were only detected in the less remote lake, after a long period of gradual and elastic changes. Unexpected synchrony was observed in diatom assemblages from geographically distant and human‐impacted lakes, whereas lakes under similar broad‐scale environmental factors (climate and ecoregion) showed asynchronous community trajectories over time. Our results reveal a complex ecological history and indicate that Andean lakes in Ecuador can gradually adapt and recover from a myriad of disturbances, exhibiting resilience over century to millennial timescales.

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“…Across terrestrial, marine, and freshwater ecosystems, empirical studies highlight that spatial beta diversity can show distinct phases of stability (e.g. Benito et al ., 2020; Lindholm et al ., 2020 a , b ), punctuated by periods of biotic differentiation (e.g. Pinceloup et al ., 2020) or homogenisation (e.g.…”

Section: Synthesising Drivers and Directions Of Change In Spatial Bet...mentioning

confidence: 99%

Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptual models across ecosystems

et al. 2023

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Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed ‘beta diversity’) is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta‐analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change; (ii) disturbance regime; (iii) connectivity alteration and species redistribution; (iv) habitat change; and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mech...

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Spatial and Temporal Ecological Uniqueness of Andean Diatom Communities Are Correlated With Climate, Geodiversity and Long-Term Limnological Change

Cited by 18 publications

References 90 publications

Diatom response to environmental gradients in the high mountain lakes of the Colombia’s Eastern Range

Diatom response to environmental gradients in the high mountain lakes of the Colombia’s Eastern Range

Ecological resilience in tropical Andean lakes: A paleolimnological perspective

Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptual models across ecosystems

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