scholarly journals Regulation of Seed Dormancy and Germination Mechanisms in a Changing Environment

2021 ◽  
Vol 22 (3) ◽  
pp. 1357
Author(s):  
Ewelina A. Klupczyńska ◽  
Tomasz A. Pawłowski

Environmental conditions are the basis of plant reproduction and are the critical factors controlling seed dormancy and germination. Global climate change is currently affecting environmental conditions and changing the reproduction of plants from seeds. Disturbances in germination will cause disturbances in the diversity of plant communities. Models developed for climate change scenarios show that some species will face a significant decrease in suitable habitat area. Dormancy is an adaptive mechanism that affects the probability of survival of a species. The ability of seeds of many plant species to survive until dormancy recedes and meet the requirements for germination is an adaptive strategy that can act as a buffer against the negative effects of environmental heterogeneity. The influence of temperature and humidity on seed dormancy status underlines the need to understand how changing environmental conditions will affect seed germination patterns. Knowledge of these processes is important for understanding plant evolution and adaptation to changes in the habitat. The network of genes controlling seed dormancy under the influence of environmental conditions is not fully characterized. Integrating research techniques from different disciplines of biology could aid understanding of the mechanisms of the processes controlling seed germination. Transcriptomics, proteomics, epigenetics, and other fields provide researchers with new opportunities to understand the many processes of plant life. This paper focuses on presenting the adaptation mechanism of seed dormancy and germination to the various environments, with emphasis on their prospective roles in adaptation to the changing climate.

2021 ◽  
Vol 118 (18) ◽  
pp. e2017105118
Author(s):  
Gwen S. Antell ◽  
Isabel S. Fenton ◽  
Paul J. Valdes ◽  
Erin E. Saupe

Abiotic niche lability reduces extinction risk by allowing species to adapt to changing environmental conditions in situ. In contrast, species with static niches must keep pace with the velocity of climate change as they track suitable habitat. The rate and frequency of niche lability have been studied on human timescales (months to decades) and geological timescales (millions of years), but lability on intermediate timescales (millennia) remains largely uninvestigated. Here, we quantified abiotic niche lability at 8-ka resolution across the last 700 ka of glacial–interglacial climate fluctuations, using the exceptionally well-known fossil record of planktonic foraminifera coupled with Atmosphere–Ocean Global Climate Model reconstructions of paleoclimate. We tracked foraminiferal niches through time along the univariate axis of mean annual temperature, measured both at the sea surface and at species’ depth habitats. Species’ temperature preferences were uncoupled from the global temperature regime, undermining a hypothesis of local adaptation to changing environmental conditions. Furthermore, intraspecific niches were equally similar through time, regardless of climate change magnitude on short timescales (8 ka) and across contrasts of glacial and interglacial extremes. Evolutionary trait models fitted to time series of occupied temperature values supported widespread niche stasis above randomly wandering or directional change. Ecotype explained little variation in species-level differences in niche lability after accounting for evolutionary relatedness. Together, these results suggest that warming and ocean acidification over the next hundreds to thousands of years could redistribute and reduce populations of foraminifera and other calcifying plankton, which are primary components of marine food webs and biogeochemical cycles.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1520
Author(s):  
Jin-Hong Zhang ◽  
Kun-Ji Li ◽  
Xiao-Fei Liu ◽  
Liu Yang ◽  
Shi-Kang Shen

Rapid temperature changes in mountain ecosystems pose a great threat to alpine plant species and communities. Rhododendron species, as the major component of alpine and sub-alpine vegetation, have been demonstrated to be sensitive to climate changes. Therefore, understanding how alpine Rhododendron species spread to new habitats and how their geographical distribution range shifts is crucial for predicting their response to global climate change and for facilitating species conservation and reintroduction. In this study, we applied MaxEnt modeling and integrated climate, topography, and soil variables in three periods under three climate change scenarios to predict the suitable habitat for four Rhododendron species in China. We measured the potential distribution change in each species using the change ratio and the direction of centroid shifts. The predicted results showed that (1) the threatened species R. protistum would have a maximum decrease of 85.84% in its distribution range in the 2070s under RCP 8.5, and R. rex subsp. rex as a threatened species would experience a distribution range expansion (6.62–43.10%) under all of the three climate change scenarios in the 2070s. (2) R. praestans would experience a reduction in its distribution range (7.82–28.34%) under all of the three climate change scenarios in the 2070s. (3) The four Rhododendron species would be moved to high latitudes in the north-westward direction as a whole in the future, especially the two threatened species R. protistum and R. rex subsp. rex. (4) Aside from climate variables, soil factors also exert an important influence on the distribution of Rhododendron species. This study revealed the species-specific response of Rhododendron species to climate change. The results can not only provide novel insights into conservation strategies of Rhododendron species, but also propose a valuable method for the habitat selection during the reintroduction of endangered species.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8894 ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Marco Porceddu ◽  
Caterina Angela Dettori ◽  
Gianluigi Bacchetta

Background Temperature is the main environmental factor controlling seed germination; it determines both the percentage and the rate of germination. According to the Intergovernmental Panel on Climate Change, the global mean surface temperature could increase of approximately 2–4 °C by 2090–2099. As a consequence of global warming, the period of snow cover is decreasing on several mountain areas. Thermal time approach can be used to characterise the seed germination of plants and to evaluate the germination behaviour under the climate change scenarios. In this study, the effect of different cold stratification periods on seed dormancy release and germination of Gentiana lutea subsp. lutea, a taxon listed in Annex V of the Habitats Directive (92/43/EEC), was evaluated. Furthermore, the thermal requirements and the consequences of the temperature rise for seed germination of this species were estimated. In addition, a conceptual representation of the thermal time approach is presented. Methods Seeds of G. lutea subsp. lutea were harvested from at least 50 randomly selected plants in two representative localities of the Gennargentu massif (Sardinia). Germination tests were carried out under laboratory conditions and the responses at 5, 10, 15, 20, 25 and 30 °C were recorded. Different cold stratification pre-treatments at 1 ± 1 °C (i.e. 0, 15, 30, 60 and 90 days) were applied. Successively, the base temperature (Tb) and the number of thermal units (θ, °Cd) for germination were estimated. Additionally, this study examined the consequences of an increase in temperatures based on the Representative Concentration Pathways (RPC) scenarios. Results The results indicated that from 0 to 30 days of cold stratification, the germination was null or very low. After 60 and 90 days of cold stratification the seed dormancy was removed; however, 25 and 30 °C negatively affected the germination capacity of non-dormant seeds. Seeds cold-stratified for 90 days showed a lower Tb than those stratified for 60 days. However, 60 and 90 days of cold stratification did not cause great variations in the thermal time units. Analysing the RPC scenarios, we detected that the number of days useful for dormancy release of seeds of G. lutea may be less than 30 days, a condition that does not permit an effective dormancy release. Conclusions We conclude that seeds of G. lutea need at least 60 days of cold stratification to remove dormancy and promote the germination. The thermal time model developed in this work allowed us to identify the thermal threshold requirements of seed germination of this species, increasing the knowledge of a plant threatened by global warming. Our results emphasise the need for further studies aiming at a better characterisation of germination efficiency, especially for species that require cold stratification. This would improve the knowledge on the germination mechanisms of adaptation to different future global warming conditions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Yang ◽  
Maigeng Zhou ◽  
Zhoupeng Ren ◽  
Mengmeng Li ◽  
Boguang Wang ◽  
...  

AbstractRecent studies have reported a variety of health consequences of climate change. However, the vulnerability of individuals and cities to climate change remains to be evaluated. We project the excess cause-, age-, region-, and education-specific mortality attributable to future high temperatures in 161 Chinese districts/counties using 28 global climate models (GCMs) under two representative concentration pathways (RCPs). To assess the influence of population ageing on the projection of future heat-related mortality, we further project the age-specific effect estimates under five shared socioeconomic pathways (SSPs). Heat-related excess mortality is projected to increase from 1.9% (95% eCI: 0.2–3.3%) in the 2010s to 2.4% (0.4–4.1%) in the 2030 s and 5.5% (0.5–9.9%) in the 2090 s under RCP8.5, with corresponding relative changes of 0.5% (0.0–1.2%) and 3.6% (−0.5–7.5%). The projected slopes are steeper in southern, eastern, central and northern China. People with cardiorespiratory diseases, females, the elderly and those with low educational attainment could be more affected. Population ageing amplifies future heat-related excess deaths 2.3- to 5.8-fold under different SSPs, particularly for the northeast region. Our findings can help guide public health responses to ameliorate the risk of climate change.


2020 ◽  
Vol 8 ◽  
Author(s):  
Pablo Medrano-Vizcaíno ◽  
Patricia Gutiérrez-Salazar

Nasuella olivacea is an endemic mammal from the Andes of Ecuador and Colombia. Due to its rarity, aspects about its natural history, ecology and distribution patterns are not well known, therefore, research is needed to generate knowledge about this carnivore and a first step is studying suitable habitat areas. We performed Ecological Niche Models and applied future climate change scenarios (2.6 and 8.5 RCP) to determine the potential distribution of this mammal in Colombia and Ecuador, with current and future climate change conditions; furthermore, we analysed its distribution along several land covers. We found that N. olivacea is likely to be found in areas where no records have been reported previously; likewise, climate change conditions would increase suitable distribution areas. Concerning land cover, 73.4% of N. olivacea potential distribution was located outside Protected Areas (PA), 46.1% in Forests and 40.3% in Agricultural Lands. These findings highlight the need to further research understudied species, furthering our understanding about distribution trends and responses to changing climatic conditions, as well as informig future PA designing. These are essential tools for supporting wildlife conservation plans, being applicable for rare species whose biology and ecology remain unknown.


BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Dol Raj Luitel ◽  
Mohan Siwakoti ◽  
Mohan D. Joshi ◽  
Muniappan Rangaswami ◽  
Pramod K. Jha

2019 ◽  
Vol 76 (4) ◽  
Author(s):  
Ying Guo ◽  
Yue Lu ◽  
Yousry A. El-Kassaby ◽  
Lei Feng ◽  
Guibing Wang ◽  
...  

Abstract Key message We developed a climatic response function using 20-year tree height observed from 45Ginkgo bilobaplantations in China and used it to predict the growth and habitat responses to anticipated climate change. We projected northward and upward shifts in the species habitat and productive areas, but a dramatic contraction of the species distribution is unlikely to occur at least during the present century. Context Ginkgo biloba is the only living species in the division Ginkgophyta. The species exists in small natural populations in southeastern China but is cultivated across China and the world. The species’ future under climate change is of concern. Aims This study was initiated to model the species’ growth response to climate change and to predict its range of suitable habitat under future climates. Methods Using height data from 45 20 years old plantations growing under a wide range of climatic conditions across China, we developed univariate and bivariate climatic response functions to identify the climate requirements of the species. Results According to the amount of variance explained (> 70%) and the high level of agreement (> 99%) with independent species occurrence coordinates, the developed climate response function was highly accurate and credible. Projections for future periods (2011–2040, 2041–2070, and 2071–2100) under the Representative Concentration Pathway 4.5 (RCP4.5) scenario indicated that the areas of potential suitable habitat would increase (25–67 million hectares). It would also be associated with northward (0.21–0.62° in latitude) and elevational (24–75 m) shifts. Conclusion Global climate change is projected to increase the area of potential suitable habitats for Ginkgo and shift its spatial distributions northward and upward.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 689
Author(s):  
Gisel Garza ◽  
Armida Rivera ◽  
Crystian Sadiel Venegas Barrera ◽  
José Guadalupe Martinez-Ávalos ◽  
Jon Dale ◽  
...  

Walker’s Manihot, Manihot walkerae, is an endangered plant that is endemic to the Tamaulipan thornscrub ecoregion of extreme southern Texas and northeastern Mexico. M. walkerae populations are highly fragmented and are found on both protected public lands and private property. Habitat loss and competition by invasive species are the most detrimental threats for M. walkerae; however, the effect of climate change on M. walkerae’s geographic distribution remains unexplored and could result in further range restrictions. Our objectives are to evaluate the potential effects of climate change on the distribution of M. walkerae and assess the usefulness of natural protected areas in future conservation. We predict current and future geographic distribution for M. walkerae (years 2050 and 2070) using three different general circulation models (CM3, CMIP5, and HADGEM) and two climate change scenarios (RCP 4.5 and 8.5). A total of nineteen spatially rarefied occurrences for M. walkerae and ten non-highly correlated bioclimatic variables were inputted to the maximum entropy algorithm (MaxEnt) to produce twenty replicates per scenario. The area under the curve (AUC) value for the consensus model was higher than 0.90 and the partial ROC value was higher than 1.80, indicating a high predictive ability. The potential reduction in geographic distribution for M. walkerae by the effect of climate change was variable throughout the models, but collectively they predict a restriction in distribution. The most severe reductions were 9% for the year 2050 with the CM3 model at an 8.5 RCP, and 14% for the year 2070 with the CMIP5 model at the 4.5 RCP. The future geographic distribution of M. walkerae was overlapped with protected lands in the U.S. and Mexico in order to identify areas that could be suitable for future conservation efforts. In the U.S. there are several protected areas that are potentially suitable for M. walkerae, whereas in Mexico no protected areas exist within M. walkerae suitable habitat.


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