Use of time, space, and food by the gymnophthalmid lizardPrionodactylus eigenmanni from the western Amazon of Brazil

1998 ◽  
Vol 76 (9) ◽  
pp. 1681-1688 ◽  
Author(s):  
Laurie J Vitt ◽  
Shawn S Sartorius ◽  
Teresa Cristina S. Avila-Pires ◽  
Maria Cristina Espósito
Keyword(s):  
Sexual Dimorphism ◽  
Body Temperatures ◽  
Terra Firme ◽  
Food Items ◽  
Use Of Time ◽  
Air Temperatures ◽  
Time Space ◽  
Different Seasons ◽  
Terra Firme Forest ◽  
Two Populations

The gymnophthalmid lizard Prionodactylus eigenmanni lives in leaf litter of terra firme forest in the western Amazon. Lizards are active during sunny and cloudy periods and body temperatures are 27.2 ± 0.19°C (mean ± SE). Body temperatures did not correlate with substrate or air temperatures: P. eigenmanni apparently gain heat by seeking temporary patches of relatively warm microhabitat. Two populations (Rio Ituxí in Amazonas and central Rondônia) were compared with respect to diet and morphology. The diet consists of a wide variety of invertebrates, but spiders, homopterans, orthopterans, and roaches constitute the majority of food items. Prey types and sizes in the two localities were similar. Females are larger than males and there is no apparent sexual dimorphism in head size as is found in many other lizards. Even though the two populations were studied in different seasons, there was no indication that wet versus dry season affected the ecology of these lizards.

Thermoregulation of the lizard Barisia imbricata at altitudinal extremes

2019 ◽  
Vol 40 (3) ◽  
pp. 349-360
Author(s):  
Natalia Fierro-Estrada ◽  
Yasmin Guadalupe González González ◽  
Donald B. Miles ◽  
Margarita Martínez Gómez ◽  
Andrés García ◽  
...  
Keyword(s):  
Body Temperature ◽  
Narrow Range ◽  
Thermal Ecology ◽  
Body Temperatures ◽  
Mean Body Temperature ◽  
Thermal Requirements ◽  
Air Temperatures ◽  
Preferred Temperatures ◽  
Environmental Temperatures ◽  
Two Populations

Abstract Ambient temperature is a primary factor affecting the physiology and activity of reptiles. Thermoregulation involves a series of mechanisms to maintain an organism’s body temperature within a narrow range. The study of thermal ecology of lizards is relevant for understanding their distribution, life history, ecology and thermal requirements. Moreover, determining how species are able to attain physiologically active body temperatures in challenging environments is necessary for assessing the risk of extinction due to climate change, especially for threatened endemic species. We evaluated and compared the thermal ecology of two populations of the viviparous lizard Barisia imbricata, at contrasting elevations (2200 and 3700 m). We obtained variation in thermal data from winter through autumn for multiple years. We determined thermal efficiency indices based on field active body temperatures, preferred temperatures (in a thermal gradient), and operative environmental temperatures (according to null models). We also recorded substrate and air temperatures at the time of capture. Mean body temperature of both populations showed a positive correlation with environmental temperatures. We found significant seasonal differences in body temperature in both populations, and between body temperatures of the two populations. Our results suggest that B. imbricata is an eurythermic species and can thermoregulate actively at any given time. However, when environmental temperatures are within the range of preferred temperatures, the species does not engage in thermoregulatory behavior. This information expands knowledge on the range of possible thermal responses to environmental variation within a species.

A New Algorithm to Reduce PAPR in STBC MIMO-OFDM System

2013 ◽  
Vol 760-762 ◽  
pp. 190-193
Author(s):  
Ya Jing Wang ◽  
Ya Zhen Li ◽  
Jing Guan
Keyword(s):  
Ofdm System ◽  
The Core ◽  
Use Of Time ◽  
Time Space ◽  
Core Technology ◽  
Mimo Ofdm ◽  
Papr Performance ◽  
And Inversion ◽  
Development Prospects ◽  
Great Development

MIMO and OFDM technology is the core technology of 4G network, and have great development prospects. The main drawback of MIMO-OFDM system is the high PAPR. This paper is based on Cross-antenna rotation and inversion and Active Constellation Extension. The paper proposed the joint algorithm to reduce PAPR in STBC MIMO-OFDM system. It makes use of time, space and frequency freedom to improve the PAPR performance. The simulation results show that the joint algorithm can effectively reduce the PAPR value and do not increase the bit error rate in STBC MIMO-OFDM system.

Arbuscular mycorrhizal fungal communities along a pedo-hydrological gradient in a Central Amazonian terra firme forest

Mycorrhiza ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Rejane de Oliveira Freitas ◽  
Erika Buscardo ◽  
Laszlo Nagy ◽  
Alex Bruno dos Santos Maciel ◽  
Rosilaine Carrenho ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Terra Firme ◽  
Terra Firme Forest ◽  
Arbuscular Mycorrhizal Fungal

scholarly journals ESTRUTURA E DINÂMICA EM UMA FLORESTA DENSA DE TERRA FIRME, SUDESTE DO AMAPÁ, BRASIL

Nativa ◽  
2018 ◽  
Vol 6 ◽  
pp. 802
Author(s):  
Ronaldo Oliveira dos Santos ◽  
Rubiene Neto Soares ◽  
Bruno Costa do Rosário ◽  
Robson Borges de Lima ◽  
Jadson Coelho de Abreu
Keyword(s):  
Vertical Structure ◽  
Ecological Groups ◽  
Terra Firme ◽  
The Past ◽  
Structure And Dynamics ◽  
Major Species ◽  
Diameter Structure ◽  
Terra Firme Forest ◽  
Number Of Individuals ◽  
Late Stages

O objetivo deste estudo foi analisar a variação da estrutura diamétrica de uma comunidade arbórea em floresta densa de terra firme e dos principais grupos de espécies de estágios iniciais e tardios de sucessão, bem como caracterizar a estrutura vertical da floresta. Em 2016, foram inventariadas todas as árvores com DAP ≥ 10 cm e mensuradas suas alturas. Em 2017, as árvores foram reamostradas. A estrutura diamétrica foi analisada por meio do quociente “q” De Liocourt para: a comunidade, principais espécies de maior VI e os grupos ecológicos (GE). A análise da estrutura vertical da vegetação foi feita pela distribuição do número de árvores nos estratos, utilizando-se três métodos: (I) – Sanquetta (1995), (II) - Souza (1990), e (III) – Souza et al. (2003). A estrutura diamétrica da comunidade e dos GE no período avaliado foi caracterizada por árvores de pequeno porte nas menores classes de diâmetro. O Método II não trouxe bons resultados sobre o comportamento das espécies no estrato médio por apresentar fortes tendências em concentrar um maior número de indivíduos nesse estrato. Os resultados da estrutura altimétrica e diamétrica demonstraram indicativos que a exploração antrópica no passado alterou a estrutura da floresta.Palavras-chave: espécies amazônicas, “q” De Licocourt, estratificação, incremento. STRUCTURE AND DYNAMICS IN A DENSE OF TERRA FIRME FOREST, SOUTHEAST OF AMAPÁ, BRAZIL ABSTRACT:The study aimed to analyze the variation of the diameter structure of a arboreal community in a dense terra firme forest and the main groups of species of early and late stages of succession, as well as characterize the vertical structure of the forest. In 2016, all trees with DBH ≥ 10 cm were inventoried and their heights measured indirectly. In 2017, the trees were re-measured. The diametric structure was analyzed using the "q" De Liocourt quotient for: the community, major species of higher (VI) and ecological groups (EG). The analysis of the vertical structure of the vegetation was made by the distribution of the number of trees in the strata, using three methods: (I) – Sanquetta (1995), (II) - Souza (1990), and (III) – Souza et al. (2003). The diametric structure of the community and the EG during the period evaluated was characterized by small trees in the smallest diameter classes. Method II did not bring good results on the behavior of the species in the middle stratum because it presents strong tendencies to concentrate a greater number of individuals in this stratum. The results of the altimetric and diametric structure have demonstrated that antropic exploration in the past has altered the structure of the forest.Keywords: amazonian species, “q” De Licocourt, stratification, increment.

scholarly journals FLORISTIC COMPOSITION AND DIVERSITY IN TERRA FIRME FOREST UNDER WATER STRESS IN THE AMAZON

CERNE ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 403-412
Author(s):  
Ana Maria Moreira Fernandes ◽  
Maria de Lourdes Pinheiro Ruivo ◽  
Antônio Carlos Lola Costa
Keyword(s):  
Water Stress ◽  
Floristic Composition ◽  
Terra Firme ◽  
Terra Firme Forest

Analysis of Changes in the Natural and Climatic Conditions of the Functioning of the Construction Industry (Operation of Buildings and Structures) in the Region

2018 ◽  
Vol 931 ◽  
pp. 1031-1036
Author(s):  
Boris A. Ashabokov ◽  
Alexander V. Shapovalov ◽  
Alla A. Tashilova
Keyword(s):  
Construction Industry ◽  
Extreme Values ◽  
Climatic Conditions ◽  
Daily Maximum ◽  
Climatic Zones ◽  
Air Temperatures ◽  
Average Maximum ◽  
European Part Of Russia ◽  
Different Seasons ◽  
Southern Russia

The manifestations of climatic changes on the territory of the south of the European part of Russia are considered. The estimates for the changes in the seasonal and annual average, maximum and minimum air temperatures, in the seasonal and annual sum of precipitation, daily maximum precipitation as well as the dynamics of the number of their extreme values ​​in different climatic zones of southern Russia and in different seasons are obtained. Possible effects of climate change on the functioning of the construction industry in different climatic zones of the region are considered.

scholarly journals Vantanea maculicarpa (Humiriaceae): a new tree species from French Guiana

Phytotaxa ◽  
2018 ◽  
Vol 338 (1) ◽  
pp. 130 ◽  
Author(s):  
JULIEN ENGEL ◽  
DANIEL SABATIER
Keyword(s):  
New Species ◽  
Tree Species ◽  
French Guiana ◽  
Similar Species ◽  
Terra Firme ◽  
Terra Firme Forest ◽  
A New Species

A new species of Humiriaceae, Vantanea maculicarpa, growing in French Guiana terra-firme forest is described and illustrated. This new species is distinguished from all other species of Vantanea by fruits covered by white lenticels, a character so far unknown in this genus. It also presents a pubescent intrastaminal disk, a feature encountered in two other Vantanea species only: it is further distinguished from V. parviflora, the morphologically most similar species, by more stamens and from V. ovicarpa by a much smaller rough endocarp with five valves. A key to the species of French Guiana and the IUCN status Least Concern (LC) are proposed.

scholarly journals Amazon climatic factors driving terpene composition of Iryanthera polyneura Ducke in terra-firme forest: A statistical approach

PLoS ONE ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. e0224406 ◽  
Author(s):  
Erika Ramos Martins ◽  
Ingrit Elida Collantes Díaz ◽  
Mateus Luís Barradas Paciencia ◽  
Sergio Alexandre Frana ◽  
Márcia Ortiz Mayo Marques ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Climatic Factors ◽  
Terra Firme ◽  
Terra Firme Forest

scholarly journals Summer Diet of Two White-tailed Deer, Odocoileus virginianus, Populations Living at Low and High Density in Southern Québec

2004 ◽  
Vol 118 (3) ◽  
pp. 360 ◽  
Author(s):  
Claude Daigle ◽  
Michel Crête ◽  
Louis Lesage ◽  
Jean-Pierre Ouellet ◽  
Jean Huot
Keyword(s):  
Odocoileus Virginianus ◽  
Feeding Habits ◽  
High Density ◽  
Rumen Content ◽  
Régime Alimentaire ◽  
Food Items ◽  
Growing Seasons ◽  
Content Analyses ◽  
Two Populations ◽  
Foraging Time

We investigated summer diets of two White-tailed Deer (Odocoileus virginianus) populations through rumen content analyses. Samples from 93 deer were collected in a low density, LD (1 deer/km2) and a high density, HD (14 deer/km2) area of southern Québec during the growing seasons of 1997 and 1998. Availability of preferred forage in forests was greater in LD than in HD, whereas agriculture covered a larger proportion of the area in HD than LD. Rumen composition differed between the two populations. Deer from HD consumed less forbs and leaves of shrubs and trees than did LD deer, whereas they consumed more fruits, grasses and farm crops. The rarity in HD rumens of food items common in LD, as well as in many parts of the White-tailed Deer range (i.e., Lilliacae), indicated that deer could not compensate for the rarity of preferred forest forage by increasing foraging time and had to feed on cultivated crops. Rumen contents of LD deer had a higher level of cell solubles and lignin, which reflected their greater reliance on quality forage growing in forests. Feeding habits and forage quality can explain why deer body size decreased in HD between the 1970s and 1990s whereas LD deer remained large.Nous avons examiné le régime alimentaire estival de deux populations de cerf de Virginie (Odocoileus virginianus) par l’analyse du contenu des rumens. Des échantillons ont été prélevés sur 93 cerfs provenant d’un secteur à faible densité de cerfs, LD, (1 cerf/km2) et d’un secteur à haute densité, HD, (14 cerfs/km2) du sud du Québec durant la saison de croissance des végétaux de 1997 et 1998. La disponibilité des aliments forestiers préférés des cerfs était plus grande dans LD que dans HD alors que la proportion du territoire agricole était supérieure dans HD. La composition des rumens des cerfs de chacune des régions différait. Les cerfs de HD ont consommé de moins grandes proportions de plantes herbacées et de feuilles d’arbustes et d’arbres que ceux du secteur LD, mais de plus grandes proportions de fruits, de graminées et de plantes agricoles. La rareté dans les rumens du secteur HD d’aliments communs dans ceux du secteur LD et dans plusieurs autres régions de l’aire de répartition du cerf (e.g., Lilliacae), indique que les cerfs du secteur HD ne pouvaient compenser pour la rareté de leurs aliments préférés par un accroissement de la durée de la quête alimentaire, et qu’ils devaient consommer des plantes agricoles. Les cerfs de LD ont mangé des aliments contenant plus de solubles cellulaires et de lignine que ceux de HD, ce qui reflète une consommation de plantes forestières de bonne qualité. Le régime alimentaire et la qualité de la nourriture peuvent expliquer pourquoi la taille des cerfs de HD a diminué entre les années 1970 et 1990 alors que celle des cerfs de LD est demeurée grande.

Sign in / Sign up

Export Citation Format

Share Document