scholarly journals Daño por herbivoría en plántulas de encino en bordes de fragmentos de bosque mesófilo de montaña

2017 ◽  
pp. 29
Author(s):  
Juan Antonio Reynoso ◽  
Guadalupe Williams-Linera

Herbivory damage on Quercus xalapensis Humb. et Bonpl. seedlings was experimentally determined in two cloud forest fragments (Veracruz, Mexico), one with an abrupt edge (forest contiguous to a one-year old stand), and another with a soft edge (forest contiguous to a 10 year-old stand). Sets of seedlings were planted in transects parallel to the border. The experiments were conducted in the warm-dry (April-May) and warm-wet (July-August) seasons. Herbivory damage was measured at the beginning and at the end of each season. Weekly, microclimatic variables were measured in the same positions in which seedlings were planted. During the wet season, herbivory was similar at different distances from the border (ca. 2%), but during the dry season, herbivory was higher at the forest border (2.75-11.75%) than at the old-field (0.50-0.75%). Herbivory and air temperature were higher, and air humidity and soil water content were lower in the abrupt than in the soft edge. Our results suggest that herbivory levels on oak seedlings depend on modulating factors such as the edge type and the season of the year.

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Amanda M. Hale

Abstract I used playbacks of recorded group song to survey and capture Black-breasted Wood-Quail (Odontophorus leucolaemus), a cloud forest endemic, in Monteverde, Costa Rica. This species is abundant in the dense understory of large windbreaks, forest fragments, and continuous forest of the Monteverde Reserve Complex. Mean covey size was four adults (range = 2–9 adults) and mean density, which did not differ between fragmented and continuous forest, was one covey per 3.3 ha. Wood-Quail defended all-purpose group territories and coveys persisted from one year to the next, indicating a group structure that is very different from what is found in most New World quail. A peak in breeding activity occurred at the transition from the wet to the dry season and larger groups produced significantly more juveniles than smaller groups in this population. Playbacks were a useful technique for detecting Black-breasted Wood-Quail; coveys responded to 65% of survey attempts by chorus and approach. By repeating the survey just three times, I was able to detect 91% ± 5% of all coveys that were known from extensive searches to occur in the remnant forest patches of the Monteverde community. The year-round sociality that is seen in this species is due in part to the retention of young on the natal territory beyond the age of sexual maturity. The intriguing relationship between group size and reproductive success in this population suggests the wood-quail may provide the first demonstration of a cooperative breeding system in the Galliformes.


2019 ◽  
Vol 85 ◽  
pp. 31
Author(s):  
Ana Luisa Santiago Pérez ◽  
Enrique José Jardel Peláez ◽  
Ramón Cuevas Guzmán ◽  
Francisco Martín Huerta Martínez

<p>Species composition, diversity, structure and microclimate were compared in two edge type of montane cloud forest (FF, edges with pine forest and FS, secondary shrubland) within a forest-edge-exterior gradient at Sierra de Manantlán Biosphere Reserve (Jalisco, Mexico). The cloud forest presented higher richness (126 species, 52 interior habitat specifi c) than pine forests (84) and shrublands (71). Richness and diversity were similar in FF, but species replacement was higher in FS. Density, diameter structure, basal area and canopy cover were major in FF than in FS. Microclimatic and soil condition, was gradual in FF edges and abrupt in FS edges. Tree species of the cloud forests (high density of seedlings and saplings &lt;5 cm diameter breast height) are colonizing the understory of adjacent pine forests, whereas in shrublands their establishment appears to be limited by competition with shrubs and herbaceous species and microclimatic conditions. Our results highlight the importance of considering edge type contrast in conservation and restoration of cloud forest in forest landscapes.</p>


1999 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Luis Bernardo Vázquez Hernández ◽  
Guy N. Cameron ◽  
Rodrigo A. Medellín Legorreta

Resumen:En el presente trabajo se presentan las relaciones entre dieta y demografía de dos especies de roedores (Reithrodontomys fulvescens y Peromyscus aztecus) en un bosque mesófilo de montaña y en un área perturbada del occidente de México. La información se obtuvo mediante técnicas de captura-recaptura. Las especies difirieron en la densidad poblacional, abundancia y en el tiempo de reproducción. La actividad reproductiva de P. aztecus en bosque mesófilo alcanzó sus máximos valores a mitad de la estación lluviosa y en a mitad de la estación seca-fría en el área perturbada. R. fulvescens registró la mayor actividad reproductiva en la estación húmeda en ambos hábitats. La densidad de P. aztecus mantuvo fluctuaciones a lo largo de todo el año, con picos en los meses de enero y febrero. R. fulvescens mostró el mismo patrón de densidad en ambos hábitats con lo máximos valores al final de la estación húmeda. Los hábitos alimentarios y la sobreposición de la dieta fueron evaluados mediante técnicas microhistológicas. La dieta de P. aztecus en bosque mesófilo estuvo dominada por frutos de Solanaceae, Melastomataceae, Araliaceae y Myrsinaceae. Dicotiledóneas (hojas y tallos), semillas de monocotiledóneas (Zea diploperennis) y de dicotiledóneas (Lupinus y Acacia) dominaron la dieta en R. fulvescens. Los valores más altos de sobreposición de la dieta en bosque mesófilo ocurrieron en la estación húmeda (77.6%) y el valor menor en la estación seca-caliente (25.1%). Las características nutrimentales de la dieta mostraron variación estacional. No existió una relación evidente entre los diferentes nutrimentos y la reproducción.Abstract: The relationship between diet and demography of two rodents (Reithrodontomys fulvescens and Peromyscus aztecus) in clouded forest and disturbed area of western Mexico was described. A live-traps study was conducted to obtain information about population dynamics. Species varied in population density, relative abundance, and reproduction timing, which was seasonal. Reproductive activity for P. aztecus peaked in the middle of the wet season in the clouded forest and in the wet season and middle of the dry-cold season indisturbed areas. R. fulvescens showed reproductive activity in the wet season in both habitats. Density fluctuated annually for P. aztecus in both habitats, with a peak in January - February;R. fulvescens showed the same patterns of density in both habitats with the highest values at the end of the wet season. Food habits and dietary overlap were evaluated by microhistological techniques. The diet of P. aztecus in the clouded forest was dominated by dicot fruits of Solanaceae, Melastomataceae, Araliaceae, and Myrsinaceae species. In disturbed area this species did not prefer a particular food item. Dicots (leaves and stems) dominated the diet, but seeds of monocots (Zea diploperennis) and dicots (Lupinus and Acacia) were also included. Reithrodontomys fulvescens consumed dicots species (seeds, fruits, leaves and stems). The greatest dietary overlap between species occurred in cloud forest during the wet season (77.6%), with less overlap in the dry-hot season (35.2 %). High overlap occurred in disturbed area during the wet season (68.2 %) and low values in the dry-hot season (25.1 %). Nutritional characteristics of diets showed seasonal variation.Palabras clave: Peromyscus aztecus, Reithrodontomys fulvescens, ecología poblacional, hábitos alimentarios, reproducción, occidente de México.


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.


2005 ◽  
Vol 21 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Matthew Guy Letts ◽  
Mark Mulligan

Photosynthesis was limited by low-intensity photosynthetically active radiation (PAR) and leaf wetness in a lower montane cloud forest (LMCF) of Cauca, Colombia. Mean PAR intensity remained below the saturation level for leaf-scale net photosynthesis (Pn) throughout the solar day during the wet season and for most of the solar day during the dry season. PAR represented a smaller fraction of total solar radiation (K↓) in LMCF than in lowland rain forest (LRF). In LMCF trees and shrubs, mean PAR-saturated Pn ranged from 4.3–10.6 μmol C m−2 s−1 at 1450 m, and from 3.5–10.2 μmol C m−2 s−1 at 2150 m. Pn was reduced by abaxial wetness in leaves of some trees and shrubs, and eliminated in others. This study indicates that persistent cloudiness and interception of cloud water by leaves limit LMCF productivity.


2021 ◽  
Author(s):  
Victor L Barradas ◽  
Monica Ballinas

&lt;p&gt;This research is a general reflection of the possible transmission not only of COVID-19 but of any influenza disease depending on environmental parameters such as solar radiation, air humidity and air temperature (vapor pressure deficit), evoking the Penman-Monteith model regarding the evaporation of the water that constitutes the small water droplets (aerosols) that carry the virus. In this case the evapotranspiration demand of the atmosphere with which it can be deduced that the spread of the disease will be higher in those places with less evaporative demand, that is, high air humidity and / or low temperatures, and / or low radiation intensities, and vice versa. It can also be deduced that the hours of greatest potential contagion are the night hours, while those with the lowest risk are between 2:00 p.m. and 4:00 p.m. On the other hand, in those rooms with low temperatures the contagion would be more effective. So, considering that the drops produced by a sneeze, by speaking or breathing can go beyond two meters away, it is roughly explained that the use of face masks and keeping a safe minimum distance of two meters can limit transmission of viruses and / or infections. However, this practice is not entirely safe as the environment can play an important role. What is recommended to reduce the spread of these pathogens is to produce high evaporative demands: increasing solar radiation, and increasing air temperature and reducing air humidity, which is practice that can be effective in closed rooms.&lt;/p&gt;


2021 ◽  
Author(s):  
Csenge Nevezi ◽  
Tamás Bazsó ◽  
Zoltán Gribovszki ◽  
Előd Szőke ◽  
Péter Kalicz

&lt;p&gt;In the Hidegv&amp;#237;z Valley experimental catchment in Hungary the meteorological data have been collected since the 1990s and used for various purposes including hydrological studies. Current research began in 2018&amp;#8211;19, that aimed to reveal the connections between the hydrological and botanical characteristics in riparian forests and a wet meadow. Changes that occurred in both ecosystems in the groundwater levels, soil moisture and vegetation, showed that the local meteorological events influence these factors. Therefore we decided to analyse longer periods in which meteorological extremes&lt;br&gt;strongly influenced hydrological conditions and so status of ecosystems. Further measurements and their analysis were also required because more accuracy and detail were needed for future water balance modelling.&lt;/p&gt;&lt;p&gt;The measured data between 2017&amp;#8211;2020 were chosen as a starting database. For the first analysis we selected three meteorological parameters, i. e. the precipitation, the air temperature, and the air humidity. These parameters were measured by automated instruments, except for the precipitation. We found that the automated tipping-bucket rain gauge needs validation by a manual measurement (Hellmann-type rain gauge), because the data that collected by the automated device will be invalid if the rain intensity is too high.&lt;/p&gt;&lt;p&gt;In 2017 and 2018, the annual precipitation was distributed evenly, but in the following two years we observed some extremes. In 2019 and&lt;br&gt;2020, the spring was especially dry, the lowest monthly sum was 1.2 mm in 2020 April. 2019 April was similar (19.5 mm), but after the drought&lt;br&gt;period intense rainfall events arrived in May, resulted a monthly total of 214.1 mm. Air temperature and air humidity has not been showed such extremes as the precipitation.&lt;/p&gt;&lt;p&gt;This study showed that detailed analysis of meteorological parameters is crucial for hydrological modelling data preparation because errors and extreme event can cause serious problems during modelling process and, also in case of evaluation of model results.&lt;/p&gt;&lt;p&gt;The research has been supported by the Ministry of Agriculture in Hungary.&lt;/p&gt;


2008 ◽  
Vol 25 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Carlos Henrique de Freitas ◽  
Eleonore Z. F. Setz ◽  
Alba R. B. Araújo ◽  
Nivar Gobbi

Capuchin monkeys occupy a wide range of habitats where they feed on fruits, arthropods, and vertebrates. Their large home ranges (80-900 ha) suggest that living in forest fragments may challenge their adaptability. We identified and quantified the main food items of Cebus libidinosus Spix, 1823 in forests fragments (100 ha) in southeastern Brazil. We recorded the feeding activities of two groups using scan sampling over a 13-month period. The diet was composed of fruits, crops, animal prey, seeds, plant matter and undetermined. Fruit was eaten more in the wet season than in the dry season, and maize and sugar cane consumption peaked in the early dry season. The proportion of fruit in the diet was positively correlated with fruiting intensity of zoochorous trees. The plant diet included 54 species, with maize, Rhamnidium elaeocarpus, Acrocomia aculeata, Guazuma ulmifolia and Cariniana, being most important. Although dietary composition and diversity were similar to capuchins in larger forest fragments, feeding on crops attained higher percentages at times when zoochorous fruit production was low in fragments.


Hoehnea ◽  
2009 ◽  
Vol 36 (3) ◽  
pp. 437-444 ◽  
Author(s):  
Davi Rodrigo Rossatto

Here is a communicating about time differences between branch and diameter growth in a tree community of ten species in Neotropical savanna ("cerrado") of Central Brazil. This work was conducted to study branch expansion and diameter growth in a period of one year between 2006 and 2007. Branch growth had begin in middle dry season and had the peak occurrence during the dry period in September, while diameter growth had begin in late dry season and peaked in the middle of wet season in December. The majority of species followed the same pattern. Branch growth did not have relation with rainfall, while diameter growth had a clear and positive relation with rainfall records. These results suggested that branch growth was not depend on rainfall but only on water status recover, while diameter growth probably depends strongly on water and to carbon assimilation that occurs after branch and leaf expansion.


2017 ◽  
pp. 43
Author(s):  
Guadalupe Cornejo-Tenorio ◽  
Alejandro Casas ◽  
Berenice Farfán ◽  
José Luis Villaseñor ◽  
Guillermo Ibarra-Manríquez

A study of the flora and vegetation physiognomy was conducted at the core zones of the Monarch Butterfly Biosphere Reserve, in the states of México and Michoacán. Collection of plant specimens was carried out du ring one year of field work and this activity was supplemented by a review of voucher specimens previously collected in the area and deposited at the Mexican herbaria IEB, EBUM, and MEXU. A total of 423 vascular plant species including 32 infraespecific taxa and grouped in 86 families and 244 genera were identified, Families with the largest species richness were Asteraceae (103), Lamiaceae (21), Fabaceae (17), and Scrophulariaceae (17).The most speciose genera were Salvia (13), Stevia (8), and Ageratina (7). Mexican endemic species comprised 135 (31.9%) species, which included 13 infrae spec ific taxa; 40 of these species belong to Asteraceae. Herbs were represented by 326 species, followed by shrubs (5 1) and trees (33). The main vegetation types recognized were coniferous forest (including combinations of fir, pine, and oak forests), cloud forest, anthropogenic grass land, and Quercus forest.


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