The Croonian lecture, 1995 Natural communities: structure and dynamics

1996 ◽  
Vol 351 (1344) ◽  
pp. 1113-1129 ◽  
Keyword(s):  
Species Richness ◽  
Community Ecology ◽  
Guild Structure ◽  
Structure And Dynamics ◽  
Natural Communities

A review is undertaken of various concepts in community ecology that relate to observed patterns in nature; these are species richness, diversity, guild structure, niche structure, constancy of structure, succession and the bionomic profile of communities. This understanding may allow us to better predict the effects of changes we are making in our environment.

scholarly journals Structure of three subtropical bat assemblages (Chiroptera) in the Andean rainforests of Argentina

Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Common Species ◽  
Guild Structure ◽  
Trophic Guild ◽  
Long Tail ◽  
Mist Net ◽  
Yungas Forests

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus

scholarly journals Keystone species and food webs

2009 ◽  
Vol 364 (1524) ◽  
pp. 1733-1741 ◽  
Author(s):  
Ferenc Jordán
Keyword(s):  
Current Knowledge ◽  
Interspecific Interactions ◽  
Keystone Species ◽  
Ecosystem Functions ◽  
General Interest ◽  
Interaction Structure ◽  
Structure And Dynamics ◽  
Rich Interaction ◽  
Natural Communities

Different species are of different importance in maintaining ecosystem functions in natural communities. Quantitative approaches are needed to identify unusually important or influential, ‘keystone’ species particularly for conservation purposes. Since the importance of some species may largely be the consequence of their rich interaction structure, one possible quantitative approach to identify the most influential species is to study their position in the network of interspecific interactions. In this paper, I discuss the role of network analysis (and centrality indices in particular) in this process and present a new and simple approach to characterizing the interaction structures of each species in a complex network. Understanding the linkage between structure and dynamics is a condition to test the results of topological studies, I briefly overview our current knowledge on this issue. The study of key nodes in networks has become an increasingly general interest in several disciplines: I will discuss some parallels. Finally, I will argue that conservation biology needs to devote more attention to identify and conserve keystone species and relatively less attention to rarity.

Variability in species richness and guild structure in two species-rich grasslands

1995 ◽  
Vol 30 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Leoš Klimeš ◽  
Jan Wim Jongepier ◽  
Ivana Jongepierová
Keyword(s):  
Species Richness ◽  
Guild Structure

scholarly journals Signal categorization by foraging animals depends on ecological diversity

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
David William Kikuchi ◽  
Anna Dornhaus ◽  
Vandana Gopeechund ◽  
Thomas N Sherratt
Keyword(s):  
Species Richness ◽  
Community Ecology ◽  
Phenotypic Diversity ◽  
Ecological Diversity ◽  
Evolutionary Processes ◽  
Warning Signals ◽  
Prey Diversity ◽  
Virtual Ecosystem ◽  
Predator Psychology ◽  
The Way

Warning signals displayed by defended prey are mimicked by both mutualistic (Müllerian) and parasitic (Batesian) species. Yet mimicry is often imperfect: why does selection not improve mimicry? Predators create selection on warning signals, so predator psychology is crucial to understanding mimicry. We conducted experiments where humans acted as predators in a virtual ecosystem to ask how prey diversity affects the way that predators categorize prey phenotypes as profitable or unprofitable. The phenotypic diversity of prey communities strongly affected predator categorization. Higher diversity increased the likelihood that predators would use a ‘key’ trait to form broad categories, even if it meant committing errors. Broad categorization favors the evolution of mimicry. Both species richness and evenness contributed significantly to this effect. This lets us view the behavioral and evolutionary processes leading to mimicry in light of classical community ecology. Broad categorization by receivers is also likely to affect other forms of signaling.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Community Ecology ◽  
Community Dynamics ◽  
Spatial Scales ◽  
River Mouth ◽  
Extrinsic Factors ◽  
Local Species Richness ◽  
Community Convergence ◽  
Local Filters

<em>Abstract</em>.—Community ecology increasingly seeks to integrate the influences of regional and historical processes with species interactions within local habitats. This broadened perspective is largely based on comparative approaches that employ “natural experiments” to identify factors shaping community structure. Because coastal rivers are separated from one another by insurmountable barriers (oceans or land), freshwater fishes are particularly well suited for comparative analyses of factors that influence fish community organization. In this chapter, we review how this comparative approach shed light on large-scale biodiversity gradients, community saturation, community convergence, density compensation, and the role of intrinsic and extrinsic factors in community dynamics. The main factors (e.g., river mouth discharge and history) empirically related to species richness of a river are well identified, and metacommunity ecology provides a fruitful conceptual framework for understanding how regional (river) species richness translates into local species richness. Much work remains to identify factors explaining differences among whole river basin assemblages with regard to ecological traits (e.g., trophic status and life history) composition and to assess whether trait-related environmental and biotic local filters act similarly over large spatial scales. One important conclusion that can be drawn from the studies reviewed here is that history cannot be neglected whatever the scale of investigation (global, river, or site). A second conclusion is that historical effects are not strong enough to blur the occurrence of qualitatively repeatable patterns of community structure over large spatial scale, which is encouraging because it suggests development of general predictive models of community structure is an attainable goal.

scholarly journals Spider diversity (Arachnida; Araneae) in different plantations of Western Ghats, Wayanad region, India

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fathima P Shabnam ◽  
Smija M K ◽  
Sruthi Rajeevan ◽  
Puthanpurayil K Prasadan ◽  
Ambalaparambil V Sudhikumar
Keyword(s):  
Species Richness ◽  
Functional Groups ◽  
Western Ghats ◽  
Rubber Plantation ◽  
Guild Structure ◽  
Coffee Plantation ◽  
Tea Plantation ◽  
Orb Web ◽  
Kerala State ◽  
The Western Ghats

The study was conducted to explore the spider diversity in different plantations of Western Ghats Wayanad, Kerala state, India. The investigation was carried out for the period from February 2019 to February 2020. A total of 100 species belonging to 74 genera under 20 families were recorded from the selected habitats. This represents 51% families recorded from the Western Ghats, Kerala. The highest species richness was found in the coffee plantation (site A) with 56 species belonging to 12 families. The tea plantation (site B) recorded 27 species belonging to 11 families. The rubber plantation (site C) showed the lowest species richness with 17 species belonging to ten families. Guild structure analyses of the collected spiders revealed nine functional groups viz.., orb-web builders, stalkers, ambushers, cob-web builders, ground runners, foliage runners, tent web builders, sheet-web builders and funnel web builders. The pattern and the architecture of webs varied among different families. During the period of study, five different web patterns were recorded- orb web, tent web, cob web, sheet web and funnel web. It is concluded that the structure of the vegetation is expected to influence the diversity of spiders in different plantations.

A numerical model for biodiversity

1992 ◽  
Vol 338 (1286) ◽  
pp. 383-391 ◽  
Keyword(s):  
Species Richness ◽  
Numerical Model ◽  
Community Ecology ◽  
Physical Environment ◽  
Preliminary Report ◽  
Trophic Levels ◽  
The Sun ◽  
Evolutionary Models ◽  
Single Process ◽  
Environmental Feedback

A numerical model is presented based on Alfred Lotka’s notion that the mathematics of evolutionary models would be simpler, not more complex, if the evolution of the organisms and of their physical environment was considered as a single process. The model is concerned with the climate and the com m unity ecology of an imaginary planet, Daisyworld, in orbit around a star like the Sun. The stabilizing influence of environmental feedback is used to enable experiments in community ecology that might otherwise be impossible. The model planetary ecosystem is populated with numerous types of organism distributed in up to three trophic levels. There follows a preliminary report of an exploration of this model planet and an account of its biodiversity and species richness.

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