103 research outputs found
Exploratory modeling: Extracting causality from complexity
On 22 May 2011 a massive tornado tore through Joplin, Mo., killing 158 people. With winds blowing faster than 200 miles per hour, the tornado was the most deadly in the United States since modern record keeping began in the 1950s. Β©2014. American Geophysical Union. All Rights Reserved
Plant-soil feedbacks promote coexistence and resilience in multi-species communities
Both ecological theory and empirical evidence suggest that negative frequency dependent
feedbacks structure plant communities, but integration of these findings has been limited.
Here we develop a generic model of frequency dependent feedback to analyze coexistence
and invasibility in random theoretical and real communities for which frequency dependence
through plant-soil feedbacks (PSFs) was determined empirically. We investigated community
stability and invasibility by means of mechanistic analysis of invasion conditions and numerical
simulations. We found that communities fall along a spectrum of coexistence types ranging
from strict pair-wise negative feedback to strict intransitive networks. Intermediate community
structures characterized by partial intransitivity may feature βkeystone competitorsβ which disproportionately
influence community stability. Real communities were characterized by stronger
negative feedback and higher robustness to species loss than randomly assembled
communities. Partial intransitivity became increasingly likely in more diverse communities.
The results presented here theoretically explain why more diverse communities are characterized
by stronger negative frequency dependent feedbacks, a pattern previously encountered
in observational studies. Natural communities are more likely to be maintained by strict negative
plant-soil feedback than expected by chance, but our results also show that community
stability often depends on partial intransitivity. These results suggest that plant-soil feedbacks
can facilitate coexistence in multi-species communities, but that these feedbacks may also initiate
cascading effects on community diversity following from single-species loss.DEB - 0919434, DEB - 1050237, DEB-1556664, DEB-173804
ΠΠ°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ½ΠΎΡΡΠΈ Π² Π»ΠΈΠ½ΠΈΠΈ ΠΏΡΠΈΠ²ΠΎΠ΄Π° ΠΏΡΠΎΠΊΠ°ΡΠ½ΠΎΠΉ ΠΊΠ»Π΅ΡΠΈ Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ Π΅Ρ ΡΠ°Π±ΠΎΡΡ
ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΡΠ°Π±ΠΎΡΡ ΠΊΠ»Π΅ΡΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½Ρ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ½ΠΎΡΡΠΈ Π½Π° ΡΠΏΠΈΠ½Π΄Π΅Π»ΡΠ½ΠΎΠΌ ΠΈ ΠΌΠΎΡΠΎΡΠ½ΠΎΠΌ ΡΡΠ°ΡΡΠΊΠ°Ρ
ΠΏΠ΅ΡΠΈΠΎΠ΄ΠΈΡΠ΅ΡΠΊΠΈ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ ΠΈΠ·ΠΌΠ΅Π½ΡΠ΅ΡΡΡ Π·Π° ΡΡΠ΅Ρ ΠΈΠ·Π½ΠΎΡΠ° ΡΠΎΡΠ»Π΅Π½ΡΠ΅ΠΌΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ Π·Π°Π·ΠΎΡΠΎΠ². Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½Π½ΡΠ΅ Π·Π°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ
ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡ ΠΏΡΠΎΠ³Π½ΠΎΠ·ΠΈΡΠΎΠ²Π°ΡΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΡΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π½Π°Π³ΡΡΠ·ΠΊΠΈ Π² Π»ΠΈΠ½ΠΈΠΈ
ΠΏΡΠΈΠ²ΠΎΠ΄Π°
Long term impacts of transitions in charcoal production systems in tropical biomes
Mitigation of greenhouse gas emissions through transitions to biomass-based renewable energy may result in higher land needs, affecting ecosystem services and livelihoods. Charcoal is a biomass-based renewable energy that provides energy for hundreds of millions of households worldwide and generates income for 40 million people. However, it currently causes up to 7% of the global deforestation rate. In the absence of affordable alternative fuels, it is necessary to identify conditions that foster sustainable charcoal production. In this study, we (a) develop a stylized model that simulates feedbacks between forest biomass and charcoal production, and (b) use the model to examine the effects of interventions that foster sustainable charcoal systems through transitions to communal management or private systems, increases in carbonization efficiency and charcoal demand reductions. Our model simulations suggest that at low demand, a transition is unnecessary. At intermediate to high demands, interventions that increase carbonization efficiency and/or reduce demand should be combined with transitions to communal management (at intermediate forest biomass levels) or private systems (at low forest biomass levels) to ensure long-term sustainability of charcoal systems and avoid collapse within 100 years. These results highlight multiple pathways for sustainable charcoal production systems tailored to meet supply and demand. All pathways are feasible across tropical biomes and could foster the simultaneous continuation of forests and charcoal production in the near future
Π‘ΡΡΡΠΊΡΡΡΠ½ΠΎ-Π³ΡΠ°ΠΌΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΎΡΠΎΡΠΌΠ»Π΅Π½ΠΈΠ΅ Π»ΠΈΠ½Π³Π²ΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈΡ ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ² Π² ΠΊΡΡΠΌΡΠΊΠΎΡΠ°ΡΠ°ΡΡΠΊΠΎΠΌ ΡΠ·ΡΠΊΠ΅
Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠ΅Π΄ΠΏΡΠΈΠ½ΡΡΠ° ΠΏΠΎΠΏΡΡΠΊΠ° ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
ΠΈ ΡΠ°ΡΡΠ΅ΡΠ΅ΡΠ½ΡΡ
ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠ΅ΠΉ Π»ΠΈΠ½Π³Π²ΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ² ΠΊΡΡΠΌΡΠΊΠΎΡΠ°ΡΠ°ΡΡΠΊΠΎΠ³ΠΎ ΡΠ·ΡΠΊΠ°. ΠΠΎΠ΄ΡΠΎΠ±Π½ΠΎ Π°Π½Π°Π»ΠΈΠ·ΠΈΡΡΠ΅ΡΡΡ ΡΠΎΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠ΅ ΠΎΠ΄Π½ΠΎΡΠ»ΠΎΠ²Π½ΡΡ
ΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠ½ΡΡ
ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
Π΅Π΄ΠΈΠ½ΠΈΡ. Π Π°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ ΡΠΈΠΏΠΎΠ»ΠΎΠ³ΠΈΡ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ Π΄Π²ΡΡ
ΡΠ»ΠΎΠ²Π½ΡΡ
ΡΠ΅ΡΠΌΠΈΠ½ΠΎΠ²-ΡΠ»ΠΎΠ²ΠΎΡΠΎΡΠ΅ΡΠ°Π½ΠΈΠΉ.Π£ ΡΡΠ°ΡΡΡ Π·Π΄ΡΠΉΡΠ½Π΅Π½Π° ΡΠΏΡΠΎΠ±Π° Π΄ΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½Π½Ρ ΡΡΡΡΠΊΡΡΡΠ½ΠΈΡ
ΠΎΡΠΎΠ±Π»ΠΈΠ²ΠΎΡΡΠ΅ΠΉ Π»ΡΠ½Π³Π²ΡΡΡΠΈΡΠ½ΠΈΡ
ΡΠ΅ΡΠΌΡΠ½ΡΠ² ΠΊΡΠΈΠΌΡΡΠΊΠΎΡΠ°ΡΠ°ΡΡΡΠΊΠΎΡ ΠΌΠΎΠ²ΠΈ ΡΠ° ΡΡ
Π½Π°Π»Π΅ΠΆΠ½ΡΡΡΡ Π΄ΠΎ ΡΠ°ΡΡΠΈΠ½ ΠΌΠΎΠ²ΠΈ. ΠΠΎΠΊΠ»Π°Π΄Π½ΠΎ Π°Π½Π°Π»ΡΠ·ΡΡΡΡΡΡ ΡΠΏΡΠ²Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Π½Ρ ΠΎΠ΄Π½ΠΎΡΠ»ΡΠ²Π½ΠΈΡ
Ρ Π±Π°Π³Π°ΡΠΎΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠ½ΠΈΡ
ΡΠ΅ΡΡΠ½ΠΎΠ»ΠΎΠ³ΡΡΠ½ΠΈΡ
ΠΎΠ΄ΠΈΠ½ΠΈΡΡ. Π ΠΎΠ·Π³Π»ΡΠ΄Π°ΡΡΡΡΡ ΡΠΈΠΏΠΎΠ»ΠΎΠ³ΡΡ ΡΡΡΡΠΊΡΡΡΠ½ΠΈΡ
ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ Π΄Π²ΠΎΡΠ»ΡΠ²Π½ΠΈΡ
ΡΠ΅ΡΠΌΡΠ½ΡΠ²-ΡΠ»ΠΎΠ²ΠΎΡΠΏΠΎΠ»ΡΡΠ΅Π½Ρ.The author of the article makes an effort to research into structural and parts-of-speech peculiarities of Crimean Tatar linguistic terminology. The correlation of one-word and multi-componential terminological units is analyzed in detail. The article also deals with the structural types of the two-word term combinations
Grazing away the resilience of patterned ecosystems
Ecosystemsβ responses to changing environmental conditions can be modulated by spatial self-organization. A prominent example of this can be found in drylands, where formation of vegetation patterns attenuates the magnitude of degradation events in response to decreasing rainfall. In model studies, the pattern wavelength responds to changing conditions, which is reflected by a rather gradual decline in biomass in response to decreasing rainfall. Although these models are spatially explicit, they have adopted a mean-field approach to grazing. By taking into account spatial variability when modeling grazing, we find that (over)grazing can lead to a dramatic shift in biomass, so that degradation occurs at rainfall rates that would otherwise still maintain a relatively productive ecosystem. Moreover, grazing increases the resilience of degraded ecosystem states. Consequently, restoration of degraded ecosystems could benefit from the introduction of temporary small-scale exclosures to escape from the basin of attraction of degraded states.</p
Antigonon leptopus invasion is associated with plant community disassembly in a Caribbean island ecosystem
Invasions by non-native plant species are widely recognized as a major driver of biodiversity loss. Globally, (sub-)tropical islands form important components of biodiversity hotspots, while being particularly susceptible to invasions by plants in general and vines in particular. We studied the impact of the invasive vine A. leptopus on the diversity and structure of recipient plant communities on the northern Caribbean island St. Eustatius. We used a paired-plot design to study differences in species richness, evenness and community structure under A. leptopus-invaded and uninvaded conditions. Community structure was studied through species co-occurrence patterns. We found that in plots invaded by A. leptopus, species richness was 40β50% lower, and these plots also exhibited lower evenness. The magnitude of these negative impacts increased with increasing cover of A. leptopus. Invaded plots also showed higher degrees of homogeneity in species composition. Species co-occurrence patterns indicated that plant communities in uninvaded plots were characterized by segregation, whereas recipient plant communities in invaded plots exhibited random co-occurrence patterns. These observations suggest that invasion of A. leptopus is not only associated with reduced species richness and evenness of recipient communities in invaded sites, but also with a community disassembly process that may reduce diversity between sites. Given that A. leptopus is a successful invader of (sub-)tropical islands around the globe, these impacts on plant community structure highlight that this invasive species could be a particular conservation concern for these systems
The relationship between ecosystem services and human modification displays decoupling across global delta systems
The ties between a society and its local ecosystem can decouple as societies develop and replace ecosystem services such as food or water regulation via trade and technology. River deltas have developed into important, yet threatened, urban, agricultural and industrial centres. Here, we use global spatial datasets to explore how 49 ecosystem services respond to four human modification indicators, e.g. population density, across 235 large deltas. We formed bundles of statistically correlated ecosystem services and examined if their relationship with modification changed. Decoupling of all robust ecosystem service bundles from at least one modification indicator was indicated in 34% of deltas, while 53% displayed decoupling for at least one bundle. Food-related ecosystem services increased with modification, while the other bundles declined. Our findings suggest two developmental pathways for deltas: as coupled agricultural systems risking irreversible local biodiversity loss; and as decoupled urban centres externalising the impact of their growing demands
Biodiversity mediates relationships between anthropogenic drivers and ecosystem services across global mountain, island and delta systems
Global change increasingly threatens nature, endangering the ecosystem services human wellbeing depends upon. Biodiversity potentially mediates these impacts by providing resilience to ecosystems. While biodiversity has been linked to resilience and ecosystem service supply on smaller scales, we lack understanding of whether mediating interactions between biodiversity and anthropogenic drivers are global and ubiquitous, and how they might differ between systems. Here, we examine the potential for biodiversity to mediate anthropogenic driver-ecosystem service relationships using global datasets across three distinct systems: mountains, islands and deltas. We found that driver-ecosystem service relationships were stronger where biodiversity was more intact, and weaker at higher species richness, reflecting the negative correlation between intactness and richness. Mediation was most common in mountains, then islands, then deltas; reducing with anthropogenic impact. Such patterns were found across provisioning and regulating ecosystem services, and occurred most commonly with climate change and built infrastructure. Further, we investigated the contribution of biodiversity and abiotic and anthropogenic drivers to ecosystem services. Ecosystem service supply was associated with abiotic and anthropogenic drivers alongside biodiversity, but all drivers were important to different ecosystem services. Our results empirically show the importance of accounting for the different roles that biodiversity plays in mediating human relationships with nature, and reinforce the importance of maintaining intact biodiversity in ecosystem functioning
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