Browsing by Author "Kueffer, Christoph"

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Lags in the response of mountain plant communities to climate change
(2018-02) Alexander, Jake M.; Chalmandier, Loic; Lenoir, Jonathan; Burgess, Treena I.; Essl, Franz; Haider, Sylvia; Kueffer, Christoph; McDougall, Keith L.; Milbau, Ann; Nunez, Martin A.; Pauchard, Anibal; Rabitsch, Wolfgang; Rew, Lisa J.; Sanders, Nathan J.; Pellissier, Loic
Rapid climatic changes and increasing human influence at high elevations around the world will have profound impacts on mountain biodiversity. However, forecasts from statistical models (e.g. species distribution models) rarely consider that plant community changes could substantially lag behind climatic changes, hindering our ability to make temporally realistic projections for the coming century. Indeed, the magnitudes of lags, and the relative importance of the different factors giving rise to them, remain poorly understood. We review evidence for three types of lag: "dispersal lags" affecting plant species' spread along elevational gradients, "establishment lags" following their arrival in recipient communities, and "extinction lags" of resident species. Variation in lags is explained by variation among species in physiological and demographic responses, by effects of altered biotic interactions, and by aspects of the physical environment. Of these, altered biotic interactions could contribute substantially to establishment and extinction lags, yet impacts of biotic interactions on range dynamics are poorly understood. We develop a mechanistic community model to illustrate how species turnover in future communities might lag behind simple expectations based on species\' range shifts with unlimited dispersal. The model shows a combined contribution of altered biotic interactions and dispersal lags to plant community turnover along an elevational gradient following climate warming. Our review and simulation support the view that accounting for disequilibrium range dynamics will be essential for realistic forecasts of patterns of biodiversity under climate change, with implications for the conservation of mountain species and the ecosystem functions they provide.
The Mountain Invasion Research Network (MIREN). linking local and global scales for addressing an ecological consequence of global change
(Oekom Verlag, 2014-10) Kueffer, Christoph; Daehler, Curtis; Dietz, Hansjörg; McDougall, Keith L.; Parks, Catherine; Pauchard, Aníbal; Rew, Lisa J.
Many modern environmental problems span vastly different spatial scales, from the management of local ecosystems to understanding globally interconnected processes, and addressing them through international policy. MIREN tackles one such “glocal” (global/local) environmental problem – plant invasions in mountains – through a transdisciplinary, multi-scale learning process at the science-policy interface. The approach led to a new framing of invasions in mountains, and promoted innovation by engaging scientists and practitioners.
Mountain roads and non-native species modify elevational patterns of plant diversity
(2018-06) Haider, Sylvia; Kueffer, Christoph; Bruelheide, Helge; Seipel, Tim F.; Alexander, Jake M.; Rew, Lisa J.; Arevalo, Jose R.; Cavieres, Lohengrin A.; McDougall, Keith L.; Milbau, Ann; Naylor, Bridgett J.; Speziale, Karina; Pauchard, Aníbal
Aim We investigated patterns of species richness and community dissimilarity along elevation gradients using globally replicated, standardized surveys of vascular plants. We asked how these patterns of diversity are influenced by anthropogenic pressures (road construction and non‐native species). Location Global. Time period 2008–2015. Major taxa studied Vascular plants. Methods Native and non‐native vascular plant species were recorded in 943 plots along 25 elevation gradients, in nine mountain regions, on four continents. Sampling took place in plots along and away from roads. We analysed the effects of elevation and distance from road on species richness patterns and community dissimilarity (beta‐diversity), and assessed how non‐native species modified such elevational diversity patterns. Results Globally, native and total species richness showed a unimodal relationship with elevation that peaked at lower‐mid elevations, but these patterns were altered along roads and due to non‐native species. Differences in elevational species richness patterns between regions disappeared along roadsides, and non‐native species changed the patterns’ character in all study regions. Community dissimilarity was reduced along roadsides and through non‐native species. We also found a significant elevational decay of beta‐diversity, which however was not affected by roads or non‐native species. Main conclusions Idiosyncratic native species richness patterns in plots away from roads implicate region‐specific mechanisms underlying these patterns. However, along roadsides a clearer elevational signal emerged and species richness mostly peaked at mid‐elevations. We conclude that both roads and non‐native species lead to a homogenization of species richness patterns and plant communities in mountains.
Moving up and over: redistribution of plants in alpine, Arctic, and Antarctic ecosystems under global change
(2020-12) Rew, Lisa J.; McDougall, Keith L.; Alexander, Jake M.; Daehler, Curtis C.; Essl, Franz; Haider, Sylvia; Kueffer, Christoph; Lenoir, Jonathan; Milbau, Ann; Nunez, Martin A.; Pauchard, Anibal; Rabitsch, Wolfgang
Extreme abiotic conditions, geographic isolation, and low levels of disturbance have historically provided alpine, Arctic, and Antarctic regions with low input of and relative resistance to the introduction of new species. However, the climate is warming rapidly, concomitant with intense and diversified types of human influence in these cold environments. Consequently, many plant species, both native and nonnative, are now moving or expanding their ranges to higher elevations and latitudes, creating new species interactions and assemblages that challenge biodiversity conservation. Based on our synthesis, many of the same nonnative species invade multiple cold environments, and many more could move up or over from adjoining warmer areas. Transportation networks and the disturbances associated with burgeoning development are responsible for many movements. Prevention and monitoring for nonnative plant species is of paramount importance, and management should be directed toward species that negatively impact ecosystem function or human well-being. Management of native range shifters is more complicated; most movements will be desirable, but some may be locally undesirable. Overall, plant movements into alpine, arctic, and Antarctic areas are going to increase, and management will need to be adaptive because species movements and assemblages of the past will not reflect those of the future.
Running off the road: roadside non-native plants invading mountain vegetation
(2018-06) McDougall, Keith L.; Lembrechts, Jonas; Rew, Lisa J.; Haider, Sylvia; Cavieres, Lohengrin A.; Kueffer, Christoph; Milbau, Ann; Naylor, Bridgett J.; Nuñez, Martin A.; Pauchard, Aníbal; Seipel, Tim F.; Speziale, Karina L.; Wright, Genevieve T.; Alexander, Jake M.
Prevention is regarded as a cost-effective management action to avoid unwanted impacts of non-native species. However, targeted prevention can be difficult if little is known about the traits of successfully invading non-native species or habitat characteristics that make native vegetation more resistant to invasion. Here, we surveyed mountain roads in seven regions worldwide, to investigate whether different species traits are beneficial during primary invasion (i.e. spread of non-native species along roadside dispersal corridors) and secondary invasion (i.e. percolation from roadsides into natural adjacent vegetation), and to determine if particular habitat characteristics increase biotic resistance to invasion. We found primary invasion up mountain roads tends to be by longer lived, non-ruderal species without seed dispersal traits. For secondary invasion, we demonstrate that both traits of the non-native species and attributes of the receiving natural vegetation contribute to the extent of invasion. Non-native species that invade natural adjacent vegetation tend to be shade and moisture tolerant. Furthermore, non-native species invasion was greater when the receiving vegetation was similarly rich in native species. Our results show how mountain roads define which non-native species are successful; first by favouring certain traits in mountain roadsides (the key dispersal pathway to the top), and secondly by requiring a different set of traits when species invade the natural adjacent vegetation. While patterns in species traits were observed at a global level, regional abiotic and biotic variables largely generated region-specific levels of response, suggesting that management should be regionally driven.