Abstract
Humans cultivate thousands of economic plants (i.e. plants with economic value) outside their native ranges. To analyze how this contributes to naturalization success, we combine global ...databases on economic uses and naturalization success of the world’s seed plants. Here we show that naturalization likelihood is 18 times higher for economic than non-economic plants. Naturalization success is highest for plants grown as animal food or for environmental uses (e.g. ornamentals), and increases with number of uses. Taxa from the Northern Hemisphere are disproportionately over-represented among economic plants, and economic plants from Asia have the greatest naturalization success. In regional naturalized floras, the percentage of economic plants exceeds the global percentage and increases towards the equator. Phylogenetic patterns in the naturalized flora partly result from phylogenetic patterns in the plants we cultivate. Our study illustrates that accounting for the intentional introduction of economic plants is key to unravelling drivers of plant naturalization.
The global loss of floristic uniqueness Yang, Qiang; Weigelt, Patrick; Fristoe, Trevor S ...
Nature communications,
12/2021, Letnik:
12, Številka:
1
Journal Article
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Regional species assemblages have been shaped by colonization, speciation and extinction over millions of years. Humans have altered biogeography by introducing species to new ranges. However, an ...analysis of how strongly naturalized plant species (i.e. alien plants that have established self-sustaining populations) affect the taxonomic and phylogenetic uniqueness of regional floras globally is still missing. Here, we present such an analysis with data from native and naturalized alien floras in 658 regions around the world. We find strong taxonomic and phylogenetic floristic homogenization overall, and that the natural decline in floristic similarity with increasing geographic distance is weakened by naturalized species. Floristic homogenization increases with climatic similarity, which emphasizes the importance of climate matching in plant naturalization. Moreover, floristic homogenization is greater between regions with current or past administrative relationships, indicating that being part of the same country as well as historical colonial ties facilitate floristic exchange, most likely due to more intensive trade and transport between such regions. Our findings show that naturalization of alien plants threatens taxonomic and phylogenetic uniqueness of regional floras globally. Unless more effective biosecurity measures are implemented, it is likely that with ongoing globalization, even the most distant regions will lose their floristic uniqueness.
The ecological contexts that promote larger brains have received considerable attention, but those that result in smaller-than-expected brains have been largely overlooked. Here, we use a global ...sample of 2062 species to provide evidence that metabolic and life history tradeoffs govern the evolution of brain size in birds and play an important role in defining the ecological strategies capable of persisting in Earth's most thermally variable and unpredictable habitats. While some birds cope with extreme winter conditions by investing in large brains (e.g., greater capacity for planning, innovation, and behavioral flexibility), others have small brains and invest instead in traits that allow them to withstand or recover from potentially deadly events. Specifically, these species are restricted to large body sizes, diets consisting of difficult-to-digest but readily available foods, and high reproductive output. Overall, our findings highlight the importance of considering strategic tradeoffs when investigating potential drivers of brain size evolution.
Aim: Of the order of 5 billion birds comprising more than 700,000 tonnes of biomass migrate across North America every year to exploit seasonal resource pulses at high latitudes during breeding. ...Despite this impressive scale, little is known about the metabolic role of these migrants in their breeding grounds across temperate ecosystems. I estimate the energy use of short-and long-distance migrant passerines as well as residents in over 2000 breeding bird communities covering the geographic scope of North America. My aim was to characterize the geographic patterns of energy use by each migratory group and test the hypothesis that seasonal patterns of resource availability structure temperate breeding bird communities. Location: North America from 25 to 69°N. Methods: I estimated the energy use of migrant and resident passerines using abundance data from the North American Breeding Bird Survey and scaling relationships for field metabolic rate as a function of body size. Linear regression was used to test the relationship between energy use by each migratory group and latitude as well as indirect measures of environmental productivity during different seasons. Results: Energy use by all groups showed a strong relationship with latitude except for long-distance migrants, which were surprisingly invariant across geography. Energy use by migrants was highest in environments with low winter productivity and high seasonality, while resident energy use was highest where annual productivity was the highest. Main conclusions: Migrant passerines contribute significantly to temperate breeding bird communities, especially in high latitudes. They account for 78% of consumption in habitats north of 50°N compared with 1.7% in the subtropics south of 35°N. Short-distance migrants are especially important to community energy use in the habitats where migrants consume the most. Future shifts in breeding bird community composition are likely to occur as climate change alters seasonal cycles of resource availability.
The extent to which different kinds of organisms have adapted to environmental temperature regimes is central to understanding how they respond to climate change. The Scholander–Irving (S-I) model of ...heat transfer lays the foundation for explaining how endothermic birds and mammals maintain their high, relatively constant body temperatures in the face of wide variation in environmental temperature. The S-I model shows how body temperature is regulated by balancing the rates of heat production and heat loss. Both rates scale with body size, suggesting that larger animals should be better adapted to cold environments than smaller animals, and vice versa. However, the global distributions of ∼9,000 species of terrestrial birds and mammals show that the entire range of body sizes occurs in nearly all climatic regimes. Using physiological and environmental temperature data for 211 bird and 178 mammal species, we test for mass-independent adaptive changes in two key parameters of the S-I model: basal metabolic rate (BMR) and thermal conductance. We derive an axis of thermal adaptation that is independent of body size, extends the S-I model, and highlights interactions among physiological and morphological traits that allow endotherms to persist in a wide range of temperatures. Our macrophysiological and macroecological analyses support our predictions that shifts inBMRand thermal conductance confer important adaptations to environmental temperature in both birds and mammals.
Understanding variation in abundance within species' ranges is fundamental for ecological and evolutionary theory and applied conservation science. The abundant‐center model provides a general ...hypothesis based on basic ecological principles and macroscale biogeographic patterns: abundance should peak near the center of a species' range, where environmental conditions are most favorable, and decline towards the periphery. Despite longstanding influence in ecological thinking, consistent support for the ubiquity of abundant‐center distributions remains elusive, and recent assessments have questioned the value of this paradigm altogether. We suggest that revisiting the simplifying assumptions that underly the model provides a productive path forward by clarifying predictions and revealing expectations for alternative distribution patterns. Towards this end, we use standardized abundance surveys of North American birds to reassess the prevalence of abundant‐center distributions in geographic and climate space, test whether deviations are associated with predictable violations of assumptions, and provide more robust expectations. After accounting for common methodological pitfalls, we find that geographic centrality is generally indicative of centrality in climate space (confirming a key model assumption) and that abundant‐center distributions occurred in 71% of passerines. To better understand exceptions, we introduce the concept of abundant‐core distributions, of which the abundant‐center is a special case. We find that 87% of species fit abundant‐core expectations, with abundances peaked and generally declining from a core region within the range. Abundance cores tended to deviate from geographic center where topographic features complicate correspondence between geography and environmental conditions (e.g. the climatically heterogenous west). Such deviations were often associated with truncated climatic availability, with core regions offset towards the continental edge or climate extremes. Overall, our analyses suggest that abundant‐center thinking provides a useful generalization for understanding spatial variation in abundance for many species. However, as with any model, its assumptions must be assessed within the context of given applications.
The macroecology of sustainability Burger, Joseph R; Allen, Craig D; Brown, James H ...
PLoS biology,
06/2012, Letnik:
10, Številka:
6
Journal Article
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The discipline of sustainability science has emerged in response to concerns of natural and social scientists, policymakers, and lay people about whether the Earth can continue to support human ...population growth and economic prosperity. Yet, sustainability science has developed largely independently from and with little reference to key ecological principles that govern life on Earth. A macroecological perspective highlights three principles that should be integral to sustainability science: 1) physical conservation laws govern the flows of energy and materials between human systems and the environment, 2) smaller systems are connected by these flows to larger systems in which they are embedded, and 3) global constraints ultimately limit flows at smaller scales. Over the past few decades, decreasing per capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socioeconomic development.
Biodiversity often stabilizes aggregate ecosystem properties (e.g. biomass) at small spatial scales. However, the importance of species diversity within communities and variation in species ...composition among communities (β-diversity) for stability at larger scales remains unclear. Using a continental-scale analysis of 1657 North American breeding-bird communities spanning 20-years and 35 ecoregions, we show local species diversity and β-diversity influence two components of regional stability: local stability (stability of bird biomass within sites) and spatial asynchrony (asynchronous fluctuations in biomass among sites). We found spatial asynchrony explained three times more variation in regional stability of bird biomass than did local stability. This result contrasts with studies at smaller spatial scales-typically plant metacommunities under 1 ha-that find local stability to be more important than spatial asynchrony. Moreover, spatial asynchrony of bird biomass increased with bird β-diversity and climate heterogeneity (temperature and precipitation), while local stability increased with species diversity. Our study reveals new insights into the scale-dependent processes regulating ecosystem stability, providing evidence that both local biodiversity loss and homogenization can destabilize ecosystem processes at biogeographic scales.
The cognitive buffer hypothesis posits that environmental variability can be a major driver of the evolution of cognition because an enhanced ability to produce flexible behavioural responses ...facilitates coping with the unexpected. Although comparative evidence supports different aspects of this hypothesis, a direct connection between cognition and the ability to survive a variable and unpredictable environment has yet to be demonstrated. Here, we use complementary demographic and evolutionary analyses to show that among birds, the mechanistic premise of this hypothesis is well supported but the implied direction of causality is not. Specifically, we show that although population dynamics are more stable and less affected by environmental variation in birds with larger relative brain sizes, the evolution of larger brains often pre-dated and facilitated the colonization of variable habitats rather than the other way around. Our findings highlight the importance of investigating the timeline of evolutionary events when interpreting patterns of phylogenetic correlation.
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