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Altered snowfall and soil disturbance influence the early life stage transitions and recruitment of a native and invasive grass in a cold desert.
- Source :
-
Oecologia [Oecologia] 2015 Feb; Vol. 177 (2), pp. 595-606. Date of Electronic Publication: 2014 Dec 25. - Publication Year :
- 2015
-
Abstract
- Climate change effects on plants are expected to be primarily mediated through early life stage transitions. Snowfall variability, in particular, may have profound impacts on seedling recruitment, structuring plant populations and communities, especially in mid-latitude systems. These water-limited and frequently invaded environments experience tremendous variation in snowfall, and species in these systems must contend with harsh winter conditions and frequent disturbance. In this study, we examined the mechanisms driving the effects of snowpack depth and soil disturbance on the germination, emergence, and establishment of the native Pseudoroegnaria spicata and the invasive Bromus tectorum, two grass species that are widely distributed across the cold deserts of North America. The absence of snow in winter exposed seeds to an increased frequency and intensity of freeze-thaw cycles and greater fungal pathogen infection. A shallower snowpack promoted the formation of a frozen surface crust, reducing the emergence of both species (more so for P. spicata). Conversely, a deeper snowpack recharged the soil and improved seedling establishment of both species by creating higher and more stable levels of soil moisture availability following spring thaw. Across several snow treatments, experimental disturbance served to decrease the cumulative survival of both species. Furthermore, we observed that, regardless of snowpack treatment, most seed mortality (70-80%) occurred between seed germination and seedling emergence (November-March), suggesting that other wintertime factors or just winter conditions in general limited survival. Our results suggest that snowpack variation and legacy effects of the snowpack influence emergence and establishment but might not facilitate invasion of cold deserts.
- Subjects :
- Bromus microbiology
Germination
Introduced Species
North America
Plants
Poaceae microbiology
Seasons
Seedlings growth & development
Seedlings microbiology
Seeds growth & development
Seeds microbiology
Soil
Bromus growth & development
Climate Change
Cold Temperature
Poaceae growth & development
Snow
Subjects
Details
- Language :
- English
- ISSN :
- 1432-1939
- Volume :
- 177
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Oecologia
- Publication Type :
- Academic Journal
- Accession number :
- 25539620
- Full Text :
- https://doi.org/10.1007/s00442-014-3180-7