Distribution Patterns of Buarremon Brush-Finches (Emberizinae) and Interspecific Competition in Andean Birds

The Auk ◽  
1995 ◽  
Vol 112 (1) ◽  
pp. 225-236 ◽  
Author(s):  
J. V. Remsen,
Keyword(s):  
Interspecific Competition ◽  
Distribution Patterns

scholarly journals The Effects of Water Levels and Interspecific Competition on Two Carex Species in a Temperate Wetland of Northeast China

2020 ◽  
Vol 12 (24) ◽  
pp. 10654
Author(s):  
Wenwen Tan ◽  
Li Sun ◽  
Xinhou Zhang ◽  
Changchun Song
Keyword(s):  
Spatial Distribution ◽  
Water Level ◽  
Interspecific Competition ◽  
Distribution Patterns ◽  
Wetland Plants ◽  
Water Levels ◽  
Carex Lasiocarpa ◽  
Temperate Wetland ◽  
The Relationship ◽  
Spatial Distribution Characteristic

Zonation along a water level is the main spatial distribution characteristic of wetland plants. This is mainly because of the influences of hydrological conditions and interspecific competition, which finally narrow the fundamental niche of a species to its realized niche. In the present study, a controlled experiment was conducted in order to analyze the relationship between Carex lasiocarpa/Carex pseudocuraica and Glyceria spiculosa, in conditions of three competitive treatments at four water levels. The results showed that in no competition, C. lasiocarpa preferred low water levels, but this preference receded when competing with G. spiculosa. In contrast, C. pseudocuraica had greater preference for low water level when competing with G. spiculosa. The root/shoot ratios of the two Carex species decreased with increasing water levels, but they were almost unaffected by different competition treatments. With the increase in water level during full competition with G. spiculosa, the competitive ability of C. lasiocarpa showed an increasing trend, whereas a contrary trend was observed in C. pseudocuraica. Our results suggested the effects of water levels and their interactions with interspecific competition varied between the two Carex species and played an important role in determining spatial distribution patterns and potential community succession of wetland plants.

Co-existence, Demography and Distribution Patterns of Two Co-occurring Ecologically Equivalent Fynbos Proteaceae Species

1998 ◽  
Vol 46 (4) ◽  
pp. 505 ◽  
Author(s):  
J. J. Midgley ◽  
N. J. Enright ◽  
R. M. Cowling
Keyword(s):  
Interspecific Competition ◽  
Competitive Exclusion ◽  
Distribution Patterns ◽  
Size Class ◽  
Fire Intensity ◽  
Shallow Soil ◽  
Cape Peninsula ◽  
Rocky Habitats

Leucospermum conocarpodendron (L.) Beuk. and Mimetes fimbriifolius Salisb. ex J.Knight co-occur in the southern Cape Peninsula, where we studied their distribution patterns, demography and fire responses. Leucospermum conocarpodendron has relatively larger seedlings and is therefore the likely competitive dominant. Adults and seedlings of both species are widely spaced and interspecific competition is unlikely to cause competitive exclusion. Differences between the two species in recruitment levels and fire-mortality are small. Thus their size-class distributions are very similar. They are restricted to shallow-soil rocky habitats, not only because of reduced fire intensity in these sites, but because these are habitats avoided by the faster growing more competitive reseeding Proteaceae. Co-existence of these two species appears to mainly be due to fire keeping populations sparse, and ants keeping individuals fairly isolated.

Distribution patterns and interthalline interactions of epiphytic foliose lichens

1992 ◽  
Vol 70 (4) ◽  
pp. 818-823 ◽  
Author(s):  
Elizabeth John
Keyword(s):  
Key Words ◽  
Interspecific Competition ◽  
Distribution Patterns ◽  
Nearest Neighbour ◽  
Tree Trunk ◽  
Ecological Strategies ◽  
Interspecific Differences ◽  
Flavoparmelia Caperata ◽  
Competition For Resources ◽  
Epiphyte Community

The foliose lichens of a corticolous epiphyte community were sampled using a grid of points and nearest neighbour sampling. Most species were found to have nonrandom distributions with respect to height and aspect on the tree trunk. The tendency of species to form exclusive patches and to contact other species showed large interspecific differences. Some formed monocultures and had fewer interspecific contacts than expected, while others did not form large patches and had more interspecific contacts than expected. Investigation of interspecific thallus overlaps revealed a hierarchy in which heavier species such as Flavoparmelia caperata (2.3 mg/mm2) overtop lighter ones such as Melanelia subaurifera (1.1 mg/mm2) more often than the converse is true. It is likely that being overtopped by another lichen puts a thallus at a disadvantage in competition for resources. The success of a species at overtopping another does not change according to location on the tree trunk. There was evidence that F. caperata excluded other species during succession. Key words: epiphytes, foliose lichens, thallus overlaps, interspecific competition, ecological strategies.

Modelling the abundance and productivity distribution to understand the habitat–species relationship: the guanaco (Lama guanicoe) case study

2020 ◽  
Vol 47 (6) ◽  
pp. 448
Author(s):  
Celina E. Flores ◽  
Laura M. Bellis ◽  
Schiavini Adrián
Keyword(s):  
Interspecific Competition ◽  
Breeding Season ◽  
Food Availability ◽  
Geographic Location ◽  
Distribution Patterns ◽  
Species Relationship ◽  
Productivity Distribution ◽  
Forage Availability ◽  
Feral Dogs ◽  
Family Groups

Abstract ContextThe conservation of large wild herbivores presents a challenge posed by the fact that their broad habitat requirements overlap with various human activities. Elucidating the factors that explain their distribution patterns provides us with a better understanding of habitat–species relationships and facilitates the design of effective management policies. AimsIdentify the natural (forage availability, weather) and anthropogenic (hunting, interspecific competition) factors that explain the abundance and productivity distribution of the guanaco. Estimate guanaco abundance and productivity and describe their distribution. MethodsWe estimated the abundance and productivity of guanaco by using aerial surveys during the breeding and non-breeding season of two consecutive years, following the strip-transect methodology; we then modelled these as a function of environmental factors by means of density surface models. Key resultsThe highest abundance and productivity of guanaco occurred mostly where mesic grassland was dominant. Guanaco abundance presented three hotspots on the basis of geographic location, and family groups were more productive at low to intermediate livestock level. Abundance was significantly higher in the breeding season for both years (5614 and 14092 individuals) than in the non-breeding season (2922 and 6926 individuals), and it was higher in 2015 than in 2014. Productivity was higher in 2015 than in 2014 (0.54 and 0.46 calves per adult respectively). ConclusionsGuanaco responded to forage availability, occupying zones with low to intermediate food availability in the breeding season, and those with the highest availability in the non-breeding season. This could be due to interspecific competition between livestock and guanaco family groups. We propose that the overall guanaco response could also be explained by social structure or by unassessed factors such as predation risk by feral dogs. ImplicationsThe guanaco could compensate for the use of habitats with a lower food availability during the breeding season by using better-quality habitats during the non-breeding season.

Zonation of two barnacle species not determined by competition

1999 ◽  
Vol 79 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Y. Miyamoto ◽  
T. Noda ◽  
S. Nakao
Keyword(s):  
Survival Rate ◽  
Interspecific Competition ◽  
Distribution Patterns ◽  
Physical Stress ◽  
Recruitment Process ◽  
Mortality Pattern ◽  
Barnacle Species ◽  
Tide Level ◽  
Chthamalus Challengeri ◽  
Northern Japan

Two barnacle species (Semibalanus cariosus and Chthamalus challengeri) were studied during two years at Hokkaido, northern Japan, to find the interspecies boundary and to determine whether interspecific competition (interference and pre-emption) is important in maintaining the zonation in our study system. Both barnacle species showed tide level dependent distribution patterns in the boundary zone. Semibalanus cariosus was dominant at lower levels; this pattern was determined by post-recruitment mortality. This mortality pattern seemed to be set by physical stress because recruitment density and survival rate were not correlated with the cover of other species, and mortality was higher in higher zones where physical stress is more severe. Chthamalus challengeri was dominant at higher levels; this pattern was determined by recruitment. The recruitment density and survival rate of this species were not affected by the covers of other species, thus, neither interference nor pre-emption significantly affected the distribution pattern. Interspecific competition appears to be less important in organizing barnacle communities in our study area than in previously studied areas, however, the recruitment process is of major importance.

Biogeography and habitats of carnivorous plants

2018 ◽  
Author(s):  
J. Stephen Brewer ◽  
Jan Schlauer
Keyword(s):  
Interspecific Competition ◽  
Woody Plants ◽  
Species Coexistence ◽  
Multiple Scales ◽  
Niche Partitioning ◽  
Distribution Patterns ◽  
Carnivorous Plants ◽  
Tropical Regions

Understanding the processes involved in generating distribution patterns of carnivorous plants requires investigation at multiple scales. Carnivorous plants typically occur in warm or hot and humid or wet climates in subtropical to tropical regions of all continents. Carnivorous plants tend to grow in wet, open, and nutrient-poor habitats. Most carnivorous plants are less tolerant of dry soils than are non-carnivorous plants. The reasons why many carnivorous plants are absent from habitats with nutrient-rich soils remain unclear, but the roles of competition and soil anoxia warrant greater attention. Reduced competition from woody plants (e.g., following fires) contributes to neutral coexistence of carnivorous and noncarnivorous herbs, and there is no evidence to date in support of nutrient-niche partitioning. More studies of interspecific competition are needed to understand better the distribution patterns and drivers of species coexistence of carnivorous and noncarnivorous plants.

HUBUNGAN KEPADATAN BIVALVIA DENGAN PARAMETER LINGKUNGAN DI PESISIR TANJUNG PURA KABUPATEN BANGKA TENGAH

2020 ◽  
Vol 13 (2) ◽  
pp. 112-121
Author(s):  
Sudiyar . ◽  
Okto Supratman ◽  
Indra Ambalika Syari
Keyword(s):  
Negative Impact ◽  
Principal Component ◽  
Environmental Parameters ◽  
Data Retrieval ◽  
Distribution Patterns ◽  
Random System ◽  
System Method ◽  
Relationship Of ◽  
The Relationship ◽  
Anadara Granosa

The destructive fishing feared will give a negative impact on the survival of this organism. This study aims to analyze the density of bivalves, distribution patterns, and to analyze the relationship of bivalves with environmental parameters in Tanjung Pura village. This research was conducted in March 2019. The systematic random system method was used for collecting data of bivalves. The collecting Data retrieval divided into five research stasions. The results obtained 6 types of bivalves from 3 families and the total is 115 individuals. The highest bivalve density is 4.56 ind / m², and the lowest bivalves are located at station 2,1.56 ind / m²,  The pattern of bivalve distribution in the Coastal of Tanjung Pura Village is grouping. The results of principal component analysis (PCA) showed that Anadara granosa species was positively correlated with TSS r = 0.890, Dosinia contusa, Anomalocardia squamosa, Mererix meretrix, Placamen isabellina, and Tellinella spengleri were positively correlated with currents r = 0.933.

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