scholarly journals Does avian gut passage favour seed germination of woody species of the Chaco Serrano Woodland in Argentina?

Botany ◽  
2017 ◽  
Vol 95 (5) ◽  
pp. 493-501 ◽  
Author(s):  
María Celeste Díaz Vélez ◽  
Ana Elisa Ferreras ◽  
Wesley Rodrigues Silva ◽  
Leonardo Galetto

Frugivorous birds are key dispersal agents of many plant species and also may facilitate seed germination after gut passage. However, the general effects of gut passage on seed germination are still not clear, with positive, negative, and neutral effects reported on seed germination. We evaluated seed germination of seven bird-dispersed plant species of the Chaco Serrano Woodland in Córdoba, Argentina: Celtis ehrenbergiana (Klotzsch) Liebm., Condalia spp. Cav., Lantana camara L., Lithraea molleoides (Vell.) Engl., Lycium cestroides Schltdl., Schinus fasciculatus (Griseb.) I.M. Johnst., and Zanthoxylum coco Gillies. We compared germination percentages and germination speed among seeds ingested by birds, manually extracted seeds, and seeds from intact fruits to understand which mechanisms are acting on bird gut-passed seeds. For six plant species, the action of frugivorous birds increased seed germination percentages and germination speed, through scarification, deinhibition, or combined mechanisms. Our results contribute to a better understanding of the mechanisms acting on seeds passed through bird gut. Also, we show the pivotal role that frugivorous birds exert on the seed germination of native woody plant species in the threatened ecosystem of the Chaco Serrano Woodland.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Abyot Dibaba ◽  
Teshome Soromessa ◽  
Alemayehu Kefalew ◽  
Admassu Addi

This study was conducted in Agama Forest in Kafa Zone, Southwestern Ethiopia, to assess species diversity, vegetation structure, and regeneration status of woody species. A systematic sampling technique was employed to collect vegetation data. Sixty (60) sample plots of 25 m × 25 m were laid at 300 m intervals all along ten grids interspaced 800 m apart. Sample plots of 25 m × 25 m were used to record DBH and H of all woody plant species reaching a DBH >2.5 cm and height >2 m. For the inventory of seedling and sapling, two subplots of 2 m × 5 m were used at the beginning and the end of the baseline on opposite sides of the main quadrat. Vegetation data such as DBH, height, seedling, and sapling density of woody species were recorded in each plot. Altogether, 72 woody plant species of 65 genera and 35 families were identified. Analysis of selected tree species showed diverse population structures. This study showed that small trees and shrubs dominated the Agama Forest, which revealed its status under a secondary regeneration stage. Study on the structure and regeneration of some woody species indicated that there are species that require urgent conservation measures. Sound management and monitoring, as well as maintenance of biodiversity and cultural and economic values of the forest, require conservation activities that encourage sustainable uses of the forest and its products.


2016 ◽  
Vol 64 (2) ◽  
pp. 859 ◽  
Author(s):  
José Miguel Romero Saritama ◽  
César Pérez-Rúiz

The study of functional morphological traits enables us to know fundamental aspects of the dynamics of plant communities in local and global habitats. Regenerative morphological traits play an important role in defining plant history and ecological behavior. Seed and fruit characteristics determine to a large extent the patterns for dispersal, germination, establishment and seedling recruitment a given species exhibits on its natural habitat. Despite their prominent role, seed and fruit traits have been poorly studied at the community level of woody plant species in neo-tropical dry forests. In the present study we aimed at i) evaluate the functional role of morphological traits of seeds, fruits and embryo in woody plant species; ii) determine which are the morphological patterns present in seeds collected from the community of woody species that occur in neo-tropical dry forests; and iii) compare woody plant species seed mass values comparatively between neo-tropical dry and tropical forests. To do so, mature seeds were collected from 79 plant species that occur in the Tumbesian forest of Southwest Ecuador. The studied species included the 42 and 37 most representative tree and shrubbery species of the Tumbesian forest respectively. A total of 18 morphological traits (seven quantitative and 11 qualitative) were measured and evaluated in the seeds, fruits and embryos of the selected species, and we compared the seeds mass with other forest types. Our results showed a huge heterogeneity among traits values in the studied species. Seed mass, volume and number were the traits that vary the most at the community level, i.e. seed length ranged from 1.3 to 39 mm, and seed width from 0.6 to 25 mm. Only six embryo types were found among the 79 plant species. In 40 % of the cases, fully developed inverted embryos with large and thick cotyledons to store considerable amount of nutrients were recorded. We concluded that highly variable and functionally complementary morphological traits occur among the studied woody plants of the dry Tumbesian forest. The latter favors a plethora of behavioral mechanisms to coexist among woody species of the dry forest in response to the environmental stress that is typical of arid areas.


2017 ◽  
Vol 1 (1) ◽  
pp. 40-53
Author(s):  
SISAY TEGEGNE ◽  
BIKILA WORKINEH

Tegegne S, Workineh B. 2017. Vegetative structure, floristic composition and natural regeneration of a species in Ylat Forest in Meket Woreda, Northeastern Ethiopia. Asian J For 1: 40-53. The natural forest of Ylat in Meket Woreda, Northeastern Ethiopia was examined to decide the vegetative structure, floristic formation and natural regeneration of woodland species and to supply data on sustainable administration of the woody plants in specific and the woodland founts in common. Systematic sampling design was used in this study to gather vegetation information. For each of the sampling sites, five transect lines having fiftyfour primary plots with 400 m2 (20m × 20m) each were laid out to gather the information on woody species along 200m line transects. A total of 60 vascular plant species having a place to 41 families and 56 genera were identified of which 13 (21.67%) were trees, 31 (51.67%) bushes, 6 (10%) climbers and 10 species (16.66) of herbs. Of all the families, Lamiaceae (8.33%) and Fabaceae, Rosaceae, Solanaceae and Euphorbiaceae 3 species (5%) were the most overwhelming woody plant species and followed by Sapindaceae, Aloaceae, Ranunclaceae, Poaceae, Oleaceae, Polygonaceae and Cucurbitaceae contains 2 species each (3.33%). A total of 2652 woody plant species individuals (1227.77 individual/ha) were found of which 405 individuals were Myrsine africana and 19 individuals were Millettia ferruginea and 20 individuals were Dombeya torrida. This data showed the highest and the lowest number of woody plant species. The thickness of woody species with DBH ≥ 2.5cm was 1227.77 individual/ha, basal zone was 1 m2 /ha, frequency of woody species was 258. The overall Shannon diversity and evenness of woody species was 2.94 and 0.84 respectively, demonstrating that the diversity and evenness of woody species within the timberland is moderately high. The woody plant species having the highest importance value index (IVI) were Erica arborea (36.31) followed by Allophylus abyssinicus (28.65) whereas Hagenia abyssinica, Myrica salicifolia, Euphorbia tirucalli, Calpurnia aurea were the lowest IVI and should be given conservation priority. Finally, this study showed that the population structure of the most woody plant species in Ylat Timberland was in a great state of regeneration recruitment level.


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Ayalew Sebsibe Tegene ◽  
Feleke Woldeyes Gamo ◽  
Simon Shibru Cheche

This study was conducted on Doshke forest in Chencha wereda, Gamo Gofa zone, South Ethiopia, with the objective of determining woody vegetation composition, structuren, and community types of woody plant species. Systematic sampling method was used to collect vegetation data. A total of 42 quadrats each with 400 m2 (20 m X 20 m) were established along four lines transects for woody species and regenerations. All the collected woody plant species were identified in National Herbarium of Ethiopia. Data used to describe vegetation structure were recorded from the quadrats. Sorensens’s similarity coefficient and Shannon-Wiener diversity index were also used to detect similarities and to compute species diversity and evenness respectively. A total of 44 woody species belonging to 40 genera and 28 families were recorded in the forest. The family Myrsinaceae and Rubiaceae were found to exhibit the highest number of species each with 4 species. The hierarchical cluster analysis using PC-ORD version 5.0 computer programs revealed four community types, of which Maesa lanceolata-Allophylus abyssinicus community type (C2) exhibited the highest species diversity and evenness. The structural analysis of Doshke forest revealed that the density of tree species in Doshke forest decreases with increasing height and DBH classes. The forest is characterized by high density of woody species in the lower class than in the higher. The most dominant tree species recorded were Syzygium guineense, Ilex mitis, and Galiniera saxiferaga. Three layers of woody species were identified from the study of vertical stratification. Studies on the regeneration of the forest indicated that there are species that require urgent conservation measures. Generally, Doshke forest possesses many economically and ecologically important plant species. It can be considered as the biodiversity conservation center in general and the forest genetic resources conservation in particular.


2011 ◽  
Vol 27 (03) ◽  
pp. 249-258 ◽  
Author(s):  
Christopher A. J. O'Kane ◽  
Kevin J. Duffy ◽  
Bruce R. Page ◽  
David W. Macdonald

Abstract:To clarify the potential influence of different browsers in the same guild on woody vegetation, dietary overlap and separation between elephant, giraffe, kudu, nyala and impala was assessed in Hluhluwe-iMfolozi Park, South Africa. Woody species browsed, browsing heights, plant-parts browsed and browsing versus grazing were recorded over 2 y by direct observation. We obtained 3068 browse records. Niche breadth (Levins' measure) and overlap (Schoener's index) in species browsed and browsing heights were calculated. Annual and seasonal differences in these measurements, plant-part use and browsing versus grazing were assessed. Elephant utilized the largest number (n = 78) of different woody plant species. Overlap in species browsed was lower between elephant and other browsers than amongst the latter. Seasonal rainfall influenced the range of woody plants utilized, niche breadth in terms of species browsed and browsing versus grazing. Marked resource depletion caused elephant, contrary to theoretical predictions, to narrow niche breadth in terms of species browsed. However, resource depletion rarely had a significant effect on interspecific overlap in species browsed or overlap in browsing heights, on actual browsing heights or plant-parts utilized. A small suite (n = 8) of woody species formed the core diet of all guild members, implying the potential for synergistic impacts by guild members on these species and for competition between populations of different guild members.


Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jan W. van Wagtendonk ◽  
Peggy E. Moore ◽  
Julie L. Yee ◽  
James A. Lutz

Abstract Background The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Results Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. Conclusions In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.


Sign in / Sign up

Export Citation Format

Share Document