scholarly journals The allometry of movement predicts the connectivity of communities

2020 ◽  
Vol 117 (36) ◽  
pp. 22274-22280 ◽  
Author(s):  
Jack Hartfelder ◽  
Chevonne Reynolds ◽  
Richard A. Stanton ◽  
Muzi Sibiya ◽  
Ara Monadjem ◽  
...  
Keyword(s):  
Large Scale ◽  
Allometric Scaling ◽  
Animal Movement ◽  
Community Level ◽  
Conservation Strategies ◽  
Bird Diversity ◽  
Individual Species ◽  
Translocation Experiment ◽  
Community Theory ◽  
Dispersal Distances

Connectivity has long played a central role in ecological and evolutionary theory and is increasingly emphasized for conserving biodiversity. Nonetheless, connectivity assessments often focus on individual species even though understanding and preserving connectivity for entire communities is urgently needed. Here we derive and test a framework that harnesses the well-known allometric scaling of animal movement to predict community-level connectivity across protected area networks. We used a field translocation experiment involving 39 species of southern African birds to quantify movement capacity, scaled this relationship to realized dispersal distances determined from ring-and-recovery banding data, and used allometric scaling equations to quantify community-level connectivity based on multilayer network theory. The translocation experiment explained observed dispersal distances from ring-recovery data and emphasized allometric scaling of dispersal based on morphology. Our community-level networks predicted that larger-bodied species had a relatively high potential for connectivity, while small-bodied species had lower connectivity. These community networks explained substantial variation in observed bird diversity across protected areas. Our results highlight that harnessing allometric scaling can be an effective way of determining large-scale community connectivity. We argue that this trait-based framework founded on allometric scaling provides a means to predict connectivity for entire communities, which can foster empirical tests of community theory and contribute to biodiversity conservation strategies aimed at mitigating the effects of environmental change.

scholarly journals Fencing affects African wild dog movement patterns and population dynamics

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Helen M. K. O'Neill ◽  
Sarah M. Durant ◽  
Stefanie Strebel ◽  
Rosie Woodroffe
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Animal Movement ◽  
Landscape Connectivity ◽  
Ecological Impact ◽  
Movement Patterns ◽  
Wrong Side ◽  
African Wild Dog ◽  
Wild Dog ◽  
Wild Dogs

Abstract Wildlife fences are often considered an important tool in conservation. Fences are used in attempts to prevent human–wildlife conflict and reduce poaching, despite known negative impacts on landscape connectivity and animal movement patterns. Such impacts are likely to be particularly important for wide-ranging species, such as the African wild dog Lycaon pictus, which requires large areas of continuous habitat to fulfil its resource requirements. Laikipia County in northern Kenya is an important area for wild dogs but new wildlife fences are increasingly being built in this ecosystem. Using a long-term dataset from the area's free-ranging wild dog population, we evaluated the effect of wildlife fence structure on the ability of wild dogs to cross them. The extent to which fences impeded wild dog movement differed between fence designs, although individuals crossed fences of all types. Purpose-built fence gaps increased passage through relatively impermeable fences. Nevertheless, low fence permeability can lead to packs, or parts of packs, becoming trapped on the wrong side of a fence, with consequences for population dynamics. Careful evaluation should be given to the necessity of erecting fences; ecological impact assessments should incorporate evaluation of impacts on animal movement patterns and should be undertaken for all large-scale fencing interventions. Where fencing is unavoidable, projects should use the most permeable fencing structures possible, both in the design of the fence and including as many purpose-built gaps as possible, to minimize impacts on wide-ranging wildlife.

scholarly journals Winter fidelity, movements, and energy expenditure of Midcontinent Greater White-fronted Geese

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jay A. VonBank ◽  
Mitch D. Weegman ◽  
Paul T. Link ◽  
Stephanie A. Cunningham ◽  
Kevin J. Kraai ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Time Allocation ◽  
Large Scale ◽  
Animal Movement ◽  
Transition Probabilities ◽  
Winter Period ◽  
Daily Movement ◽  
Regional Energy ◽  
Wintering Areas ◽  
Wintering Distribution

Abstract Background Animal movement patterns are the result of both environmental and physiological effects, and the rates of movement and energy expenditure of given movement strategies are influenced by the physical environment an animal inhabits. Greater white-fronted geese in North America winter in ecologically distinct regions and have undergone a large-scale shift in wintering distribution over the past 20 years. White-fronts continue to winter in historical wintering areas in addition to contemporary areas, but the rates of movement among regions, and energetic consequences of those decisions, are unknown. Additionally, linkages between wintering and breeding regions are generally unknown, and may influence within-winter movement rates. Methods We used Global Positioning System and acceleration data from 97 white-fronts during two winters to elucidate movement characteristics, model regional transition probabilities using a multistate model in a Bayesian framework, estimate regional energy expenditure, and determine behavior time-allocation influences on energy expenditure using overall dynamic body acceleration and linear mixed-effects models. We assess the linkages between wintering and breeding regions by evaluating the winter distributions for each breeding region. Results White-fronts exhibited greater daily movement early in the winter period, and decreased movements as winter progressed. Transition probabilities were greatest towards contemporary winter regions and away from historical wintering regions. Energy expenditure was up to 55% greater, and white-fronts spent more time feeding and flying, in contemporary wintering regions compared to historical regions. White-fronts subsequently summered across their entire previously known breeding distribution, indicating substantial mixing of individuals of varying breeding provenance during winter. Conclusions White-fronts revealed extreme plasticity in their wintering strategy, including high immigration probability to contemporary wintering regions, high emigration from historical wintering regions, and high regional fidelity to western regions, but frequent movements among eastern regions. Given that movements of white-fronts trended toward contemporary wintering regions, we anticipate that a wintering distribution shift eastward will continue. Unexpectedly, greater energy expenditure in contemporary wintering regions revealed variable energetic consequences of choice in wintering region and shifting distribution. Because geese spent more time feeding in contemporary regions than historical regions, increased energy expenditure is likely balanced by increased energy acquisition in contemporary wintering areas.

scholarly journals Modeling large-scale dispersal distances

2002 ◽  
Vol 151 (2-3) ◽  
pp. 279-292 ◽  
Author(s):  
Emmanuel Paradis ◽  
Stephen R. Baillie ◽  
William J. Sutherland
Keyword(s):  
Large Scale ◽  
Dispersal Distances

scholarly journals A trait-based approach to assess climate change sensitivity of freshwater invertebrates across Swedish ecoregions

2014 ◽  
Vol 60 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Leonard Sandin ◽  
Astrid Schmidt-Kloiber ◽  
Jens-Christian Svenning ◽  
Erik Jeppesen ◽  
Nikolai Friberg
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Species Traits ◽  
Freshwater Ecosystems ◽  
Biological Data ◽  
Conservation Strategies ◽  
Measured Temperature ◽  
Buffer Strips

Abstract Freshwater habitats and organisms are among the most threatened on Earth, and freshwater ecosystems have been subject to large biodiversity losses. We developed a Climate Change Sensitivity (CCS) indicator based on trait information for a selection of stream- and lake-dwelling Ephemeroptera, Plecoptera and Trichoptera taxa. We calculated the CCS scores based on ten species traits identified as sensitive to global climate change. We then assessed climate change sensitivity between the six main ecoregions of Sweden as well as the three Swedish regions based on Illies. This was done using biological data from 1, 382 stream and lake sites where we compared large-scale (ecoregional) patterns in climate change sensitivity with potential future exposure of these ecosystems to increased temperatures using ensemble-modelled future changes in air temperature. Current (1961~1990) measured temperature and ensemble-modelled future (2100) temperature showed an increase from the northernmost towards the southern ecoregions, whereas the predicted temperature change increased from south to north. The CCS indicator scores were highest in the two northernmost boreal ecoregions where we also can expect the largest global climate change-induced increase in temperature, indicating an unfortunate congruence of exposure and sensitivity to climate change. These results are of vital importance when planning and implementing management and conservation strategies in freshwater ecosystems, e.g., to mitigate increased temperatures using riparian buffer strips. We conclude that traits information on taxa specialization, e.g., in terms of feeding specialism or taxa having a preference for high altitudes as well as sensitivity to changes in temperature are important when assessing the risk from future global climate change to freshwater ecosystems.

scholarly journals Changes in landscape composition influence the decline of a threatened woodland caribou population

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
B McLellan ◽  
R Serrouya ◽  
C Apps
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Apparent Competition ◽  
Timber Harvesting ◽  
Conservation Strategies ◽  
Home Ranges ◽  
Vital Rates ◽  
Population Declines ◽  
Woodland Caribou ◽  
Habitat Alterations

Large-scale habitat loss is frequently identified with loss of biodiversity, but examples of the direct effect of habitat alterations on changes in vital rates remain rare. Quantifying and understanding the relationship between habitat composition and changes in vital rates, however, is essential for the development of effective conservation strategies. It has been suggested that the decline of woodland caribou Rangifer tarandus caribou populations in North America is precipitated by timber harvesting that creates landscapes of early seral forests. Such habitat changes have altered the predator-prey system resulting in asymmetric predation, where predators are maintained by alternative prey (i.e. apparent competition). However, a direct link between habitat condition and caribou population declines has not been documented. We estimated survival probabilities for the threatened arboreal lichen-feeding ecotype of woodland caribou in British Columbia, Canada, at two different spatial scales. At the broader scale, observed variation in adult female survival rates among 10 distinct populations (range = 0.67-0.93) was best explained by variation in the amount of early seral stands within population ranges and population density. At the finer scale, home ranges of caribou killed by predators had lower proportions of old forest and more mid-aged forest as compared with multi-annual home ranges where caribou were alive. These results are consistent with predictions from the apparent competition hypothesis and quantify direct fitness consequences for caribou following habitat alterations. We conclude that apparent competition can cause rapid population declines and even extinction where changes in species composition occur following large scale habitat change. © 2007 The Authors. Journal compilation © 2007 British Ecological Society.

Multispecies and Watershed Approaches to Freshwater Fish Conservation

2019 ◽  
Keyword(s):  
Habitat Diversity ◽  
Reserve Design ◽  
Conservation Strategies ◽  
Individual Species ◽  
Aquatic Communities ◽  
Fish Conservation ◽  
Ecological Processes ◽  
Current Conservation ◽  
The Status ◽  
Effective Conservation

<em>Abstract</em>.—Traditional approaches to fish conservation have focused on the protection of small habitat patches or on individual species at risk of extinction. These strategies have been important yet largely have been too little and too late for widespread protection of aquatic faunas. Such small-scale and reactive approaches also are costly in terms of recovery programs and aggressive in terms of regulatory controls. Further, the linear nature of streams and the networked configuration of drainage systems suggest that a fundamentally different approach to reserve design and protected areas is necessary for effective conservation of freshwater communities when compared to terrestrial systems. Larger-scale, multispecies approaches to native fish conservation offer a more efficient and effective conservation strategy because entire fish communities and the ecological processes that support maintenance of habitat diversity can be sustained before the status of individual species deteriorates to critical levels. Protecting entire communities and watersheds also offers some resistance to climate change impacts, which rapidly are altering flow regimes and disturbance dynamics in aquatic systems. Identification and protection of high-value aquatic communities will provide an important supplement to current conservation strategies during times of increasing threats and future uncertainty.

scholarly journals Microbial Interactions in Oral Communities Mediate Emergent Biofilm Properties

2019 ◽  
Vol 99 (1) ◽  
pp. 18-25 ◽  
Author(s):  
P.I. Diaz ◽  
A.M. Valm
Keyword(s):  
Large Scale ◽  
Taxonomic Composition ◽  
Cell Interactions ◽  
Microbial Interactions ◽  
Spatial Proximity ◽  
Individual Species ◽  
Emergent Properties ◽  
Oral Diseases ◽  
Metabolic Cooperation ◽  
Cell Cell

Oral microbial communities are extraordinarily complex in taxonomic composition and comprise interdependent biological systems. The bacteria, archaea, fungi, and viruses that thrive within these communities engage in extensive cell-cell interactions, which are both beneficial and antagonistic. Direct physical interactions among individual cells mediate large-scale architectural biofilm arrangements and provide spatial proximity for chemical communication and metabolic cooperation. In this review, we summarize recent work in identifying specific molecular components that mediate cell-cell interactions and describe metabolic interactions, such as cross-feeding and exchange of electron acceptors and small molecules, that modify the growth and virulence of individual species. We argue, however, that although pairwise interaction models have provided useful information, complex community-like systems are needed to study the properties of oral communities. The networks of multiple synergistic and antagonistic interactions within oral biofilms give rise to the emergent properties of persistence, stability, and long-range spatial structure, with these properties mediating the dysbiotic transitions from health to oral diseases. A better understanding of the fundamental properties of interspecies networks will lead to the development of effective strategies to manipulate oral communities.

scholarly journals Animal movement drives variation in seed dispersal distance in a plant–animal network

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182007 ◽  
Author(s):  
E. Rehm ◽  
E. Fricke ◽  
J. Bender ◽  
J. Savidge ◽  
H. Rogers
Keyword(s):  
Seed Dispersal ◽  
Animal Movement ◽  
Bird Species ◽  
Dispersal Distance ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Gut Passage ◽  
Dispersal Distances ◽  
Seed Dispersal Distance ◽  
Passage Times

Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

scholarly journals Regeneration Technique of Bamboo Species through Nodal Segments: A Review

2020 ◽  
Vol 8 (1) ◽  
pp. 54-68
Author(s):  
Meena Maiya Suwal ◽  
Janardan Lamichhane ◽  
Dhurva Prasad Gauchan
Keyword(s):  
Large Scale ◽  
Physiological Stress ◽  
Perennial Grass ◽  
Shoot Multiplication ◽  
Nodal Segments ◽  
Individual Species ◽  
Small Scale ◽  
Scale Production ◽  
Bamboo Species

Micropropagation is an alternative technique to propagate at large scale plants to meet global plant demand. Various researchers have worked on the micropropagation technique to regenerate bamboo species by using nodal segments from years. Contamination, browning, necrosis, and acclimatization with physiological stress are the extreme problems of the micropropagation technique. But, many numbers of papers have been published on micropropagation of the bamboo species through nodal segments as explants. The proliferation of the bamboo shoots is dependent on the season of collection, size of explants, the position of explants, diversity of plants, concentration and combination of plant growth regulators, most adequate culture medium, environmental condition of the equipment, handling, and individual species. Bamboo is a monocarpic fast-growing, tall perennial grass and having the high potential to generate economic and social benefits. It helps to maintain land patterns and control soil erosion.  The long life cycle of the bamboo produces a huge amount of seeds but unfortunately, mostly, they are non-viable. So, bamboos are propagated from vegetative by cutting and air layering. However, these methods are only for a small scale and they also tend to destroy large mother plant stocks and difficult to be transported. So, the in vitro propagation technique is useful to obtain large progenies from desired genotypes. Mostly, BAP and TDZ growth hormones are widely used for shoot multiplication and IBA, NAA and IAA are used for root initiation as per developed protocols in tissue culture for large scale production. This review intends to explore an overview of the recent literature reports to summarize the importance of micropropagation by using nodal segments of bamboo species and factors influencing it.

Sign in / Sign up

Export Citation Format

Share Document