Protecting Ecosystems from Underground Invasions - Seed Bank Dynamics in a Semi-Arid Shrub-Steppe

10.5772/37706 ◽  
2012 ◽  
Author(s):  
David R. ◽  
Lynne B.
2015 ◽  
Vol 8 ◽  
pp. 651
Author(s):  
Mark K. J. Ooi

The dynamics surrounding seeds are arguably the most important drivers of population persistence in semi-arid ecosystems. To fully understand plant population persistence and, in particular, to predict the impacts of changing climatic conditions, we need to develop a clearer picture of the ecological consequences of variation in seed dormancy and germination. In this review, I focus on seeds with physical dormancy in semi-arid regions, looking at the mechanistic effects of climate on seed bank dynamics. Both pre-dispersal and post-dispersal environment effects are considered. Knowledge is lacking in the understanding of the effects of changing climate on seed production, dormancy-breaking temperature thresholds, seed longevity and seed vigour. While lessons can be learnt from the broader range of studies conducted in the agricultural sector, there is a limit as to how the results from such studies can be applied to wild species in natural ecosystems. A concerted effort to increase the amount of ecological research in native environments is needed to gain a better understanding of the effects of climate change on biodiversity.


Plant Ecology ◽  
2021 ◽  
Vol 222 (5) ◽  
pp. 647-657
Author(s):  
Alejandro Polo ◽  
Alba Fragoso ◽  
María D. Infante-Izquierdo ◽  
Francisco J. J. Nieva ◽  
Adolfo F. Muñoz-Rodríguez ◽  
...  

2005 ◽  
Vol 21 (2) ◽  
pp. 223-226 ◽  
Author(s):  
D. A. Fornara ◽  
J. W. Dalling

Many tropical pioneer species depend on the presence of high seed densities in the soil for successful recruitment following canopy disturbance (Cheke et al. 1979, Dalling & Hubbell 2002, Guevara Sada & Gómez Pompa 1972, Whitmore 1983). However determinants of variation in the composition and abundance of soil seed banks remain poorly understood. Seed bank densities can be affected by rates of seed predation and pathogen infection on the surface and in the soil, by intrinsic rates of loss in viability following dispersal, and by variation in the timing and duration of fruit production (Dalling et al. 1997, Garwood 1983, Murray & Garcia 2002). Here we compare seasonal fluctuations in seed bank density in five Panamanian forests varying in elevation and seasonality of precipitation (Table 1). We predict that lowland forests should show stronger intra-annual fluctuation in seed bank densities than montane forests because seed production and loss rates should be higher under conditions of greater resource availability, and where consistent high temperatures support greater abundance or activity of seed predators and pathogens (Brühl et al. 1999). Secondly, among lowland sites, we predict greater fluctuations in seed bank densities at drier, more seasonal sites where seasonally favourable conditions for seedling recruitment may select for interspecific synchrony in fruit production (Daubenmire 1972, Garwood 1983).


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