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Range Expansion

description1,775 papers
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lightbulbAbout this topic
Range expansion refers to the process by which a species increases its geographic distribution, often due to environmental changes, ecological interactions, or human activities. This phenomenon can impact biodiversity, ecosystem dynamics, and species interactions, and is a key area of study in ecology and conservation biology.
lightbulbAbout this topic
Range expansion refers to the process by which a species increases its geographic distribution, often due to environmental changes, ecological interactions, or human activities. This phenomenon can impact biodiversity, ecosystem dynamics, and species interactions, and is a key area of study in ecology and conservation biology.

Key research themes

1. How can computational search algorithms be optimized to reduce surplus node generation and improve memory and time efficiency in range-based pathfinding problems?

This research area investigates improvements over classical A* search algorithms in domains with large branching factors, focusing on minimizing the generation of surplus nodes—nodes with costs exceeding the optimal solution cost—which negatively impact both memory and runtime efficiency. By incorporating heuristic and domain-specific knowledge to control node expansions and avoid unnecessary computations, these improved algorithms target range expansion scenarios effectively, especially where pathfinding is guided by admissible heuristics.

Key finding: Introduced Enhanced Partial Expansion A* (EPEA*), which improves upon Partial Expansion A* (PEA*) by using an Operator Selection Function (OSF) that leverages a priori domain- and heuristic-specific knowledge to generate only... Read more

2. What formal methods allow over-approximation and efficient computation of output ranges in neural networks, and how can they facilitate safety verification in range expansions of network outputs?

This theme focuses on formal verification approaches to compute output ranges of feed-forward neural networks, particularly with ReLU activation functions, leveraging abstraction techniques to reduce computational complexity. It addresses how interval neural networks (INNs) can be constructed to over-approximate output ranges, enabling scalability in safety-critical applications where reachable sets and safe operation ranges must be determined under uncertain inputs. The goal is to maintain soundness while improving verification tractability within expanded input and output domains.

Key finding: Presented a novel abstraction technique that reduces a given feed-forward ReLU network to an interval neural network (INN) with fewer neurons and interval weights, over-approximating the original output range. By encoding... Read more

3. How do urbanization, land cover, and human population density changes influence large carnivore range expansions in Europe?

This theme investigates correlations between changes in human population density, land cover (forest and agriculture), and legislative protections with the distributional expansions of three large carnivores—grey wolf, Eurasian lynx, and brown bear—across Europe. It integrates multi-temporal species distribution models with landscape and socio-demographic data over two decades to understand habitat suitability changes and how anthropogenic factors promote or restrict large carnivore recolonization and range expansion in fragmented human-dominated territories.

Key finding: Using species distribution models fitted with over 50,000 occurrence points and 24 years of land cover and human population data, the study showed that increasing habitat suitability for large carnivores was positively... Read more

4. What behavioral and ecological mechanisms contribute to successful colonization and range expansion in social species and marine top predators?

This theme explores how animal prospecting behavior, social information use, and habitat selection influence dispersal decisions in social species such as Audouin's gulls, as well as how large-scale breeding range shifts affect foraging ecology and population dynamics in top marine predators like Laysan albatrosses. It synthesizes telemetry and long-term monitoring data to understand how range expansions impact the species' use of novel environments, breeding performance, and foraging strategies in new ecological ranges.

Key finding: Tracking of colonial Audouin's gulls revealed that 65% of birds prospect occupied patches and 62% visited empty patches that were colonized later, demonstrating high frequency of informed dispersal and colonization behavior... Read more
Key finding: The study documented a 4,000-km breeding range expansion of Laysan albatrosses from the Central Pacific to the Eastern Pacific off Baja California and demonstrated distinct at-sea distribution, habitat use, and foraging... Read more

5. How can range reduction and modular arithmetic techniques be utilized to optimize computation of mathematical functions over expanded argument ranges?

This theme encompasses algorithmic strategies for decomposing large-range function evaluations into computations over smaller, manageable argument intervals, employing modular and multiplicative range reduction techniques. These methods enable the usage of polynomial or rational approximations within convergence domains, improving computational accuracy and efficiency for transcendental functions. The focus is on addressing challenges due to argument size, cancellation errors, and efficient reduction steps critical for implementations in numerical and computer arithmetic.

Key finding: Developed a range reduction algorithm that accurately computes reduced arguments for functions like sine, cosine, exponential, and logarithm by decomposing computations using modular arithmetic and carefully chosen constants... Read more

All papers in Range Expansion

, the Blackfeet Tribe and Defenders of Wildlife reintroduced 123 captive-reared swift foxes (Vulpes velox (Say, 1823)) to the Blackfeet Reservation in northern Montana. Because yearling swift foxes are colonizers of vacant habitats and... more
From 1998 to 2002, the Blackfeet Tribe and Defenders of Wildlife reintroduced 123 captive-reared swift foxes ( Vulpes velox (Say, 1823)) to the Blackfeet Reservation in northern Montana. Because yearling swift foxes are colonizers of... more
Aim: Invasive species are of increasing global concern. Nevertheless, the mechanisms driving further distribution after the initial establishment of non-native species remain largely unresolved, especially in marine systems. Ocean... more
Levels of genetic variation of 18 indigenous populations of silver fir (Abies alba Mill.) were studied in Switzerland. For each of 100 trees per population, multilocus genotypes were identified using isoenzyme gene markers at 14 enzyme... more
The tropical Andes are a biodiversity hotspot, partly due to their rich and complex floristic composition. A fundamental question regarding this outstanding biodiversity is what role the Andean orogeny has played in species... more
Aim: Invasive species are of increasing global concern. Nevertheless, the mechanisms driving further distribution after the initial establishment of non-native species remain largely unresolved, especially in marine systems. Ocean... more
1. Ecological restoration often involves returning ecosystem structure to some predisturbance reference state, but ecosystem function must also recover if restoration efforts are to be self-sustaining over the long term. In the... more
Historical and modern disturbance regimes, stand structures, and landscape dynamics in piñon-juniper vegetation of the western United States. Rangeland Ecology & Management, 62(3), 203-222.
Ø Golden jackals seem to favor heterogeneous landscapes and proximity to rivers and wetlands. Ø Discrepancies among countries with different history of colonization highlight the dynamic nature of the species distribution. Ø The... more
Survival after cold chilling and spring emergence of pea leafminer, Liriomyza huidobrensis (Blanchard), were evaluated in both the Þeld and laboratory in 2001 and 2002. Spring emergence was evaluated through the use of traps placed in... more