scholarly journals Overlooked Parrot Seed Dispersal in Australia and South America: Insights on the Evolution of Dispersal Syndromes and Seed Size in Araucaria Trees

Author(s):  
José L. Tella ◽  
Guillermo Blanco ◽  
Francisco V. Dénes ◽  
Fernando Hiraldo
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Huiliang Liu ◽  
Daoyuan Zhang ◽  
Xuejun Yang ◽  
Zhenying Huang ◽  
Shimin Duan ◽  
...  

Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude) of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude), which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory), and anemochorous species were most abundant. Seed mass (F=3.50,P=0.01), seed size (F=8.31,P<0.01), and seed shape (F=2.62,P=0.04) differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight) (P=0.15), seed size (P=0.38), or seed shape (variance) (P=0.95) and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F=3.64,P=0.01) and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces.


2013 ◽  
Vol 20 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Yong Yang

A numerical analysis of Ephedra L. was conducted based on 29 characters of reproductive organs. The results indicate that species are not grouped according to their geographic ranges, sect. Alatae is in one group, sect. Asarca excluding E. cutleri and E. viridis consists of a Eu-asarca group while sect. Ephedra plus E. cutleri and E. viridis of the traditional sect. Asarca make up a third expanded Ephedra group. The Old World sect. Monospermae including E. rhytidosperma, E. equisetina, E. nebrodensis, E. monosperma and E. procera was rediscovered in this study while those Himalayan endemic species (e.g. E. minuta, E. likiangensis, E. saxatilis, E. dawuensis and E. gerardiana) used to be grouped in the Old World sect. Monospermae are clustered together with sect. Scandentes including E. foeminea, E. ciliata, E. altissima and E. fragilis. This study further confirms that the adaptive seed dispersal syndromes of sect. Asarca have originated for not only once. Some new features are introduced as related to dispersal, e.g. weight and size of seeds, and nature and thickness of the outer envelope.DOI: http://dx.doi.org/10.3329/bjpt.v20i1.15464Bangladesh J. Plant Taxon. 20(1): 51-60, 2013 (June) 


Oryx ◽  
2018 ◽  
Vol 52 (3) ◽  
pp. 418-426 ◽  
Author(s):  
Aurélie Albert-Daviaud ◽  
Sarah Perillo ◽  
Wolfgang Stuppy

AbstractMadagascar is one of the most threatened biodiversity hotspots, and protection of its biodiversity is becoming increasingly urgent as deforestation of the island continues. For the long-term success of conservation efforts it is essential that key ecological processes, such as seed dispersal, are protected and restored. Therefore, the identification of ecological gaps is a vital task. For Madagascar, only little is known about plant–animal interactions, and traditional methods of ecological research are too time-consuming to provide crucial information about breakdowns in these interactions. To identify likely dispersal gaps we therefore used a theoretical approach to analyse plant–disperser interactions in Madagascar. We used data science tools to impute missing data on relevant plant traits to subsequently predict the most likely dispersal agents for each of Madagascar's endemic plant species. We found that 38% of the endemic species (N = 8,784) are endozoochorous, and among these 26–41% display a primate syndrome and 17–19% a bird syndrome (depending on the definition of syndromes). This lower percentage of endozoochorous species and higher percentage of species with a primate syndrome in Madagascar compared to other tropical areas reflects the unusual disperser guild on the island. Only five bird species but 20 lemur species are frugivorous, and 16 of those lemur species are currently threatened with extinction. The disappearance of frugivorous lemurs would significantly change the vegetation dynamics of Madagascar's ecosystems, and a high proportion of Madagascar's endemic plants would enter an extinction vortex.


FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1751
Author(s):  
Wedson Batista dos Santos ◽  
Luiz Carlos Marangon ◽  
Fernando José Freire ◽  
Rafael Leite Braz ◽  
José Edson De Lima Torres ◽  
...  

The objective of this study was to assess the patterns of seed dispersal syndromes of woody plants from nine forest fragments distributed at different altitude levels on the Araripe plateau, in Pernambuco, Brazil. For data collection, we divided the altitudes within the region into three categories: lower level (altitudes ≤600 m); intermediate level (600< altitudes <750 m); and higher level (altitudes ≥750 m). We registered nine fragments, three per altitude level. In each of them, we distributed 20 rectangular sampling units with 250 m², totaling a sampling area of 4.5 ha. We quantified, collected, and identified woody plants with a diameter at breast height higher than or equal to 0.1 m (DBH 1.30 m ≥0.10 m). We characterized the dispersal syndrome according to the characteristics of the fruits and seeds and based on a literature review. In the whole region, we sampled 6,987 individuals, distributed in 35 families, 82 genera, and 153 species. Approximately 41% of all individuals are dispersed by animals, 37% by the plant’s own mechanisms, and 21% by the wind. In terms of dispersal, 47% of species were classified as zoochorous, 23% as autochorous, and 14% as anemochorous. Seed dispersal patterns vary according to altitude levels, with higher regions tending to present greater representativeness of biotic dispersers and lower ones, abiotic.


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