Comparative effects of desiccation, heat shock and high temperatures on seed germination of savanna and forest tree species

2013 ◽  
Vol 39 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Leandro C. Ribeiro ◽  
Fabian Borghetti
2014 ◽  
Vol 37 (2) ◽  
pp. 161-164
Author(s):  
Pitambar Negi

The natural regeneration in Juniperus polycarpos is quite low due to seed dormancy. While studying the seed germination behaviour of Juniperus polycarpos, a twin seedling was found germinated from a single seed which has been reported. This is the first instance of occurrence of polyembryonic seedlings in Juniperus polycarpos which have been reported in this paper. The twin seedlings have been resulted due to the phenomenon of polyembryony which is of rare occurrence in this species, however, the production of twin seedlings has been reported earlier also in other forest tree species. The twin seedlings were found to be independent having separate taproots and cotyledons. The seedlings were later transplanted in a polybags filled with Soil: Sand: FYM (2:1:1 :) to observe the further growth of twin seedlings. After three months, it was noticed that both the twin seedlings shriveled and died where as normal seedlings continued to grow normally and produced all the essential features of a plant.


2011 ◽  
Vol 31 (4) ◽  
pp. 402-413 ◽  
Author(s):  
Ting-Wu Liu ◽  
Fei-Hua Wu ◽  
Wen-Hua Wang ◽  
Juan Chen ◽  
Zhen-Ji Li ◽  
...  

Plant Ecology ◽  
2021 ◽  
Author(s):  
Valéria Forni Martins ◽  
Rafaela Letícia Brito Bispo ◽  
Priscilla de Paula Loiola

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Fujita

AbstractThis study examined the mechanisms of facilitation and importance of seed dispersal during establishment of forest tree species in an Afrotropical woodland. Seedling survival of Syzygium guineense ssp. afromontanum was monitored for 2.5 years at four different microsites in savannah woodland in Malawi (southeastern Africa) under Ficus natalensis (a potential nurse plant), Brachystegia floribunda (a woodland tree), Uapaca kirkiana (a woodland tree), and at a treeless site. The number of naturally established forest tree seedlings in the woodland was also counted. Additionally, S. guineense ssp. afromontanum seed deposition was monitored at the four microsites. Insect damage (9% of the total cause of mortality) and trampling by ungulates (1%) had limited impact on seedling survival in this area. Fire (43%) was found to be the most important cause of seedling mortality and fire induced mortality was especially high under U. kirkiana (74%) and at treeless site (51%). The rate was comparatively low under F. natalensis (4%) and B. floribunda (23%), where fire is thought to be inhibited due to the lack of light-demanding C4 grasses. Consequently, seedling survival under F. natalensis and B. floribunda was higher compared with the other two microsites. The seedling survival rate was similar under F. natalensis (57%) and B. floribunda (59%). However, only a few S. guineense ssp. afromontanum seedlings naturally established under B. floribunda (25/285) whereas many seedlings established under F. natalensis (146/285). These findings indicate that the facilitative mechanism of fire suppression is not the only factor affecting establishment. The seed deposition investigation revealed that most of the seeds (85%) were deposited under F. natalensis. As such, these findings suggest that in addition to fire suppression, dispersal limitations also play a role in forest-savannah dynamics in this region, especially at the community level.


2021 ◽  
Vol 161 ◽  
pp. 106158
Author(s):  
Misagh Parhizkar ◽  
Mahmood Shabanpour ◽  
Isabel Miralles ◽  
Artemio Cerdà ◽  
Nobuaki Tanaka ◽  
...  

2001 ◽  
Vol 158 (12) ◽  
pp. 1547-1554 ◽  
Author(s):  
Agueda María González-Rodríguez ◽  
Michael Tausz ◽  
Astrid Wonisch ◽  
María Soledad Jiménez ◽  
Dieter Grill ◽  
...  

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