Abstract
Worldwide, mountain glaciers are shrinking rapidly. Consequently, large areas are becoming available for the development of novel alpine ecosystems. These harsh environments, however, delay ...primary succession. In this study with a local community, we conducted an inclusion experiment to investigate whether
Llama glama
influences soils and vegetation primary succession following glacial retreat. At the foot of the Uruashraju glacier in the Cordillera Blanca, Peru (~ 4680 m.a.s.l.), we established four llama inclusion plots and four control plots that we studied from 2019 to 2022, 24–40 years after deglacierization. After three years, the llama plots had significantly increased soil organic carbon and soil nitrogen. In the llama plots, we found a large, significant increase in vascular plant cover (+ 57%) between the second and third years of experimentation, and we identified four new species that were not present in 2019. Our results suggest that
Llama glama
, through their latrine behavior and role as a seed disperser, enhances the primary succession and novel ecosystem formation in recently deglacierized landscapes. Our study provides scientific support that rewilding of native Andean camelids may favor adaptation to glacier retreat and inform conservation and management strategies in proglacial landscapes.
Abstract
Landscapes nearby glaciers are disproportionally affected by climate change, but we lack detailed information on microclimate variations that can modulate the impacts of global warming on ...proglacial ecosystems and their biodiversity. Here, we use near-subsurface soil temperatures in 175 stations from polar, equatorial and alpine glacier forelands to generate high-resolution temperature reconstructions, assess spatial variability in microclimate change from 2001 to 2020, and estimate whether microclimate heterogeneity might buffer the severity of warming trends. Temporal changes in microclimate are tightly linked to broad-scale conditions, but the rate of local warming shows great spatial heterogeneity, with faster warming nearby glaciers and during the warm season, and an extension of the snow-free season. Still, most of the fine-scale spatial variability of microclimate is one-to-ten times larger than the temporal change experienced during the past 20 years, indicating the potential for microclimate to buffer climate change, possibly allowing organisms to withstand, at least temporarily, the effects of warming.
•Structured patterns of primary succession were observed under rapid warming in the alpine tropics.•Wind-dispersed species were overrepresented whereas nurse plants were poorly effective.•Poor ...facilitative effects are the result of insufficient time for nurses to establish and grow.•The time lag between warming and plant migration generates altered alpine communities.
Species range shifts and possible species extinctions in alpine regions are hypothesized being influenced by the increasing time lag between the velocity of global warming and the slowness of primary succession. We tested this hypothesis in tropical alpine environments above 4700 m a.s.l. (Central Andes) and we explored the underlying mechanisms at work by using four sites gradually deglaciated since the acceleration of warming in the late 1970’s. These post-glacial chronosequences, made available by a multidisciplinary approach combining glaciology and ecology, are extremely rare and provide a pertinent space-for-time substitution for the study of climate change effects. We found consistent patterns in plant succession (abundance, species richness and functional strategies) along the four chronosequences. Dispersal limitation was a prominent constraint for succession, even at the end of the chronosequences, leading to an overrepresentation of anemochorous species in comparison with adjacent ecosystems. Nurse plants were infrequent and their low maturity seemed to make them poorly efficient as facilitators, contrarily to the expectations made by the stress-gradient hypothesis in alpine regions. This suggests that, despite the accelerating rate of warming, the dynamics of primary succession remains slow, generating a climatic debt and hampering the adaptation to climate change in alpine plant communities.
Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated ...during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing 728 past positions of 94 glacier fronts from all continents, except Antarctica, covering the period between the Little Ice Age maxima and the present. On average, the time series span the past 190 years. From 2 to 46 past positions per glacier are depicted (on average: 7.8).
Alpine glaciers worldwide will lose most of their volume by the end of the 21st century, placing alpine ecosystems and human populations at risk. The new lands that emerge from retreating glaciers ...provide a host of challenges for ecological and human adaptation to climate change. In these novel proglacial landscapes, ecological succession and natural hazards interplay with local agriculture, hydroelectric production, mining activities, and tourism. Research has emphasized the importance of understanding adaptation around socio‐environmental systems, but regional and global management efforts that support local initiatives and connect novel proglacial landscapes to ecological, social, and cultural conservation opportunities are rare and nascent. The characteristics of these emerging lands reflect the nexus of alpine ecosystems with socio‐political histories. Often overlooked in glacial‐influenced systems are the interdependencies, feedbacks, and tradeoffs between these biophysical systems and local populations. There is no coordinated strategy to manage and anticipate these shifting dynamics, while affirming local practices and contexts. There is an opportunity to initiate a new conversation and co‐create a governance structure around these novel landscapes and develop a new framework suitable to the Anthropocene era. This article first synthesizes the rapid socio‐environmental changes that are occurring in proglacial landscapes. Second, we consider the need for integrating “bottom‐up” with “top‐down” approaches for the sustainable management of proglacial landscapes. Finally, we propose establishing a transdisciplinary initiative with policy‐related goals to further dialogues around the governance and sustainable management of proglacial landscapes. We call for increased cooperation between actors, sectors, and regions, favoring multiscale and integrated approaches.
This article is categorized under:
Climate, Ecology, and Conservation > Conservation Strategies
In proglacial landscapes news challenges and opportunities arise as new ice‐free territories emerge. The proposed High Mountain Call to Action for Landscapes and Livelihoods (HiCALL) is a proposal to further dialogues around the governance and sustainable management of proglacial landscapes.
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•Mineralogical composition of proglacial tills is related to source area lithology.•Proglacial tills may act as reservoirs for precipitation.•Effects of proglacial tills on water ...quality are related to till composition.•These effects on water quality do not propagate strongly downstream.
The Río Santa (Ancash, Peru) and its tributaries are an essential source of drinking and irrigation water. Its discharge relies on glacial meltwater, which is diminishing due to the rapid decrease in glacial extent. As a secondary effect, water quality can be compromised (e.g. pH < 3 and high concentrations of SO42− and trace metals). Although this has previously been attributed to pyrite rich Chicama bedrock exposed by glacial retreat, little is known about the occurrence of Chicama fragments in Quaternary glacial sediments and its influence on water quality. This research aims at elucidating this effect by relating observed changes in water quality in streams to presence and chemical composition of morainic ridges in the Quebrada Ulta in the Río Santa basin. Changes in water quality before and after contact with a morainic ridge were assessed using carbonate alkalinity titration, ion analysis and elemental analysis. Moreover, relative contributions of glacial meltwater and precipitation were assessed qualitatively using stable water isotope analysis. We used a novel method to explain the provenance of contaminated glacial sediments using a reconstruction of their source area. The mineralogical composition of a morainic ridge was strongly related to the geology of the source area indicating that mineralogical composition of tills may be predicted using this technique. Effects of glacial sediments in morainic ridges on water quality were minimal but depended on their mineralogical composition. Morainic ridges with a high content of Chicama shales tended to increase solute loads of Mg and SO42−. Additionally, isotope signatures suggest that during the dry season, moraines may act as reservoirs for precipitation-derived shallow groundwater. Clear trends in water quality were observed along the whole flow path of the Río Buín, which could potentially be explained by increased groundwater contribution downstream and shifts in dominant weathering mechanisms. Future research should focus on disentangling these various drivers of water quality in glacial catchments.
•We report on 188 soil samples from 9 chronosequences of deglacierization in the Andes and Alps.•Parent material strongly controls soil properties in the early stage of pedogenesis.•Potential As, Cu, ...Mo, and Mn soil toxicity is reported in Andean proglacial soils.•Initial differences in soil properties dissipate along 120-year chronosequences.
New soils formed after glacier retreat can provide insights into the rates of soil formation in the context of accelerated warming due to climate change. Recently deglacierized terrains (since the Little Ice Age) are subject to weathering and pedogenesis, and freshly exposed sediments are prone to react readily with the environment. This study aims to determine the impact of parent material and time on soil physical and chemical properties of nine proglacial landscapes distributed in the Tropical Andes and Alps. A total of 188 soil samples were collected along chronosequences of deglacierization and from sites that differed in terms of parent material and classified following three parent material groups: (1) Granodiorite-Tonalite (GT), (2) Gneiss-Shales-Schists (GSS), and (3) Mont-Blanc Granite (MBG). We determined physical and chemical soil properties such as contents of clay, silt, sand, organic carbon, bulk density (BD), pH, extractable cation (exCa, exMg, exK), elemental composition by X-ray fluorescence (Al, Si, P, S, K, Ca, Mn, Fe, Cu, Zn, As, Mo, Hg, Pb) and ICP-MS (Al, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, P, S, Zn), and mineral phase (XRD diffraction analysis). Parent material-controlled particle-size distribution, SOC, pH, available P, exCa, and exMg, whereas time since deglacierization only affected SOC and P, and exMg globally. Most of the significant differences in soil properties between parent material groups occurred within the first 17 years after deglacierization, and then we observed a homogenization between sites. While the higher SOC and P contents observed within the GT Andean sites might be due to the parent material composition leading to faster initial soil formation, we identified potential As, Cu, Mo, and Mn toxicity within those soils. Our study highlights the need to investigate further proglacial soil’s buffering capacity and carbon sequestration to globally inform the conservation and management of novel proglacial ecosystems.
Glacier forefields have long provided ecologists with a model to study patterns of plant succession following glacier retreat. While plant-survey-based approaches applied along chronosequences ...provide invaluable information on plant communities, the “space-for-time” approach assumes
environmental uniformity and equal ecological potential across sites and does not account for spatial variability in initial site conditions. Remote
sensing provides a promising avenue for assessing plant colonization dynamics using a so-called “real-time” approach. Here, we combined 36 years
of Landsat imagery with extensive field sampling along chronosequences of deglaciation for eight glacier forefields in the southwestern European
Alps to investigate the heterogeneity of early plant succession dynamics. Based on the two complementary and independent approaches, we found strong
variability in the time lag between deglaciation and colonization by plants and in subsequent growth rates and in the composition of early plant
succession. All three parameters were highly dependent on the local environmental context, i.e., neighboring vegetation cover and energy
availability linked to temperature and snowmelt gradients. Potential geomorphological disturbance did not emerge as a strong predictor of succession
parameters, which is perhaps due to insufficient spatial resolution of predictor variables. Notably, the identity of pioneer plant species was highly
variable, and initial plant community composition had a much stronger influence on plant assemblages than elapsed time since deglaciation. Overall,
both approaches converged towards the conclusion that early plant succession is not stochastic as previous authors have suggested but rather
determined by local ecological context. We discuss the importance of scale in deciphering the complexity of plant succession in glacier forefields
and provide recommendations for improving botanical field surveys and using Landsat time series in glacier forefield systems. Our work demonstrates
complementarity between remote sensing and field-based approaches for both understanding and predicting future patterns of plant succession in
glacier forefields.
Summary
The development of terrestrial ecosystems depends greatly on plant mutualists such as mycorrhizal fungi. The global retreat of glaciers exposes nutrient‐poor substrates in extreme ...environments and provides a unique opportunity to study early successions of mycorrhizal fungi by assessing their dynamics and drivers.
We combined environmental DNA metabarcoding and measurements of local conditions to assess the succession of mycorrhizal communities during soil development in 46 glacier forelands around the globe, testing whether dynamics and drivers differ between mycorrhizal types.
Mycorrhizal fungi colonized deglaciated areas very quickly (< 10 yr), with arbuscular mycorrhizal fungi tending to become more diverse through time compared to ectomycorrhizal fungi. Both alpha‐ and beta‐diversity of arbuscular mycorrhizal fungi were significantly related to time since glacier retreat and plant communities, while microclimate and primary productivity were more important for ectomycorrhizal fungi. The richness and composition of mycorrhizal communities were also significantly explained by soil chemistry, highlighting the importance of microhabitat for community dynamics.
The acceleration of ice melt and the modifications of microclimate forecasted by climate change scenarios are expected to impact the diversity of mycorrhizal partners. These changes could alter the interactions underlying biotic colonization and belowground–aboveground linkages, with multifaceted impacts on soil development and associated ecological processes.
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