Inconclusive Predictions and Contradictions: A Lack of Consensus on Seed Germination Response to Climate Change at High Altitude and High Latitude

Abstract

Climate change directly affects arctic-alpine plants and acute responses to increased temperatures may be seen in their reproductive fitness and germination ability. However, uncertainties prevail in predicting whether a future warmer climate favors or hampers seed germination in high latitude and high altitude soils and seed germination research in such systems has not been able to provide generalizable patterns of response. The available literature on this subject has been conducted at various locations contributing to difficulties in predicting the response of arctic-alpine seeds to climate change. Here, we show that discrepancies in seed collection, dormancy breaking treatments, and germination conditions found in the published literature are possible reasons for our inability to draw large scale conclusions. We explore how these factors influence the results and highlight the fact that many of the previous investigations have reported the effects of warmer temperature, rather than a warmer climate and all the associated complex environmental interactions, on seed germination. We recommend that long-term monitoring of seed response to treatments that mimic the present and future alpine climate is likely to produce more ecologically meaningful insights and suggest several practical steps that researchers can take that would facilitate greater coherence between studies.

Seeds and Seedlings in a Changing World: A Systematic Review and Meta-Analysis from High Altitude and High Latitude Ecosystems

“…Regarding the methods used by the studies included in our review, we found a great variation in the location (field or controlled conditions), instruments used, soil and substrate types, time scale and intensity in which the seeds, seedlings and environmental factors were manipulated ( Table 1 ). The wide diversity in the methods used in some of the studies included in our review have been discussed before [ 32 ]. Furthermore, the effectiveness of some of the methods used to modify environmental variables within the studies of our review and the complexity in climate change manipulation experiments have also been discussed before, for example, the unwanted side effects of open-top chambers on light, temperature and wind [ 45 , 46 , 47 ].…”

“…To date, there has been no systematic review or meta-analysis of the effects of climate change on the early life-history stages of high altitude and high latitude plants. Existing reviews and meta-analysis in the topic, while valuable, have not been systematic in their approach [ 23 ], have not included analyses of the meta-data from previously published articles [ 31 , 32 ], nor have they included ecosystems above the treeline [ 33 ]. Yet, the knowledge gaps that are revealed in a systematic review of this nature, and the new insights generated from a meta-analysis, are critical for increasing our understanding of the regeneration potential, the threats to growth and survival, and the management implications of these environments under predicted future climate change scenarios.…”

Ecology of soil seed banks: Implications for conservation and restoration of natural vegetation: A review

“…SB is the reservoir of seed capable of germinating in favorable conditions in the soil or on the surface (Jaganathan and Dalrymple, 2016). SBs are also considered to be an important potential seed source for the restoration of plant communities (Bossuyt and Honnay, 2008).…”