| 1. |
- Ehrlén, Johan, et al.
(författare)
-
Climate drives among-year variation in natural selection on flowering time
- 2020
-
Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:4, s. 653-662
-
Tidskriftsartikel (refereegranskat)abstract
- To predict long-term responses to climate change, we need to understand how changes in temperature and precipitation elicit both immediate phenotypic responses and changes in natural selection. We used 22 years of data for the perennial herb Lathyrus vernus to examine how climate influences flowering phenology and phenotypic selection on phenology. Plants flowered earlier in springs with higher temperatures and higher precipitation. Early flowering was associated with a higher fitness in nearly all years, but selection for early flowering was significantly stronger in springs with higher temperatures and lower precipitation. Climate influenced selection through trait distributions, mean fitness and trait-fitness relationships, the latter accounting for most of the among-year variation in selection. Our results show that climate both induces phenotypic responses and alters natural selection, and that the change in the optimal phenotype might be either weaker, as for spring temperature, or stronger, as for precipitation, than the optimal response.
|
|
| 2. |
- Ehrlén, Johan, 1956-, et al.
(författare)
-
Maladaptive plastic responses of flowering time to geothermal heating
- 2023
-
Ingår i: Ecology. - 0012-9658 .- 1939-9170. ; 104:10
-
Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity might increase fitness if the conditions under which it evolved remain unaltered, but becomes maladaptive if the environment no longer provides reliable cues for subsequent conditions. In seasonal environments, timing of reproduction can respond plastically to spring temperature, maximizing the benefits of a long season while minimizing the exposure to unfavorable cold temperatures. However, if the relationship between early spring temperatures and later conditions changes, the optimal response might change. In geothermally heated ecosystems, the plastic response of flowering time to springtime soil temperature that has evolved in unheated areas is likely to be non-optimal, because soil temperatures are higher and decoupled from air temperatures in heated areas. We therefore expect natural selection to favor a lower plasticity and a delayed flowering in these areas. Using observational data along a natural geothermal warming gradient, we tested the hypothesis that selection on flowering time depends on soil temperature and favors later flowering on warmer soils in the perennial Cerastium fontanum. In both study years, plants growing in warmer soils began flowering earlier than plants growing in colder soils, suggesting that first flowering date (FFD) responds plastically to soil temperature. In one of the two study years, selection favored earlier flowering in colder soils but later flowering in warmer soils, suggesting that the current level of plastic advance of FFD on warmer soils may be maladaptive in some years. Our results illustrate the advantages of using natural experiments, such as geothermal ecosystems, to examine selection in environments that recently have undergone major changes. Such knowledge is essential to understand and predict both ecological and evolutionary responses to climate warming.
|
|
| 3. |
|
|
| 4. |
- Ryberg, Eleonor E S, 1989-, et al.
(författare)
-
Quantitative assessment of past variations in Sphagnum bog community structure using paleo-species distribution modelling
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A common approach to investigating species’ niches is to examine relationships between spatial variation in environmental conditions and contemporary species occurrences, using Species Distribution Models (SDM or niche models). The relationships between past species distributions and environmental variation over time are less commonly explored. One way to examine effects on species changes over time is to use paleo-datasets to parameterize niche models, where the use of temporal variation allows for making more direct links between past species and environmental conditions through records of past changes. We examined the impact of five environmental variables (temperature, incidence of external nutrient input, local moisture, incidence of regionally dry periods, and fire activity) on temporal variation in peatland species composition, occurrences and abundances (Sphagnum, Eriophorum, Carex, and Ericaceous dwarf shrubs) using a high-resolution peat paleo-record. The paleo-dataset represents a plant macrofossil record spanning the last ~10 000 years from the Store Mosse bog (south-central Sweden). Our results showed that species composition was most strongly affected by temperature, and that the presence and abundance of different species groups were also affected by external nutrient input and the incidence of regionally dry periods. Moreover, hummock Sphagna benefited from external nutrient input and low moisture, intermediate Sphagna from cooler temperatures with no external nutrient input, and hollow Sphagna from cooler temperatures and external nutrient input. Lastly, our results showed that environmental effects in some cases differed between the successional stages of the peatland. Overall, the observed species’ responses imply that peatland carbon dynamics is expected to shift with future changes in climate. By examining links between climate and species responses of the past, the paleo-data approach in SDMs can contribute to a better understanding of the relative importance of environmental effects influencing species distributions on longer time-scales, thereby providing a valuable tool to improve predictions of future effects of climate change.
|
|
| 5. |
- Valdés, Alicia, et al.
(författare)
-
A natural heating experiment : Phenotypic and genotypic responses of plant phenology to geothermal soil warming
- 2019
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 25:3, s. 954-962
-
Tidskriftsartikel (refereegranskat)abstract
- Under global warming, the survival of many populations of sedentary organisms in seasonal environments will largely depend on their ability to cope with warming in situ by means of phenotypic plasticity or adaptive evolution. This is particularly true in high‐latitude environments, where current growing seasons are short, and expected temperature increases large. In such short‐growing season environments, the timing of growth and reproduction is critical to survival. Here, we use the unique setting provided by a natural geothermal soil warming gradient (Hengill geothermal area, Iceland) to study the response of Cerastium fontanum flowering phenology to temperature. We hypothesized that trait expression and phenotypic selection on flowering phenology are related to soil temperature, and tested the hypothesis that temperature‐driven differences in selection on phenology have resulted in genetic differentiation using a common garden experiment. In the field, phenology was related to soil temperature, with plants in warmer microsites flowering earlier than plants at colder microsites. In the common garden, plants responded to spring warming in a counter‐gradient fashion; plants originating from warmer microsites flowered relatively later than those originating from colder microsites. A likely explanation for this pattern is that plants from colder microsites have been selected to compensate for the shorter growing season by starting development at lower temperatures. However, in our study we did not find evidence of variation in phenotypic selection on phenology in relation to temperature, but selection consistently favoured early flowering. Our results show that soil temperature influences trait expression and suggest the existence of genetically based variation in flowering phenology leading to counter‐gradient local adaptation along a gradient of soil temperatures. An important implication of our results is that observed phenotypic responses of phenology to global warming might often be a combination of short‐term plastic responses and long‐term evolutionary responses, acting in different directions.
|
|
| 6. |
- Valdés, Alicia, et al.
(författare)
-
Caterpillar seed predators mediate shifts in selection on flowering phenology in their host plant
- 2017
-
Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 98:1, s. 228-238
-
Tidskriftsartikel (refereegranskat)abstract
- Variation in selection among populations and years has important implications for evolutionary trajectories of populations. Yet, the agents of selection causing this variation have rarely been identified. Selection on the time of reproduction within a season in plants might differ both among populations and among years, and selection can be mediated by both mutualists and antagonists. We investigated if differences in the direction of phenotypic selection on flowering phenology among 20 populations of Gentiana pneumonanthe during 2 yr were related to the presence of the butterfly seed predator Phengaris alcon, and if butterfly incidence was associated with the abundance of the butterfly's second host, Myrmica ants. In plant populations without the butterfly, phenotypic selection favored earlier flowering. In populations where the butterfly was present, caterpillars preferentially attacked early-flowering individuals, shifting the direction of selection to favoring later flowering. Butterfly incidence in plant populations increased with ant abundance. Our results demonstrate that antagonistic interactions can shift the direction of selection on flowering phenology, and suggest that such shifts might be associated with differences in the community context.
|
|
| 7. |
- Valdes, Alicia, et al.
(författare)
-
Contrasting effects of different landscape characteristics on population growth of a perennial forest herb
- 2014
-
Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 37:3, s. 230-240
-
Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic changes in landscape structure, such as habitat loss, habitat subdivision and edge increase, can strongly affect the performance of plants, leading to population declines and extinctions. Many studies to date have focused on single characteristics of landscape structure or single life-cycle phases, but they poorly discern the different pathways through which landscape change influences plant population dynamics via different vital rates. In this study, we evaluated the effect of two structural characteristics (habitat quantity and edge length) on vital rates and population growth rates of a perennial forest plant (Primula vulgaris) in a historically managed landscape. Areas with higher amounts of forest habitat had higher population growth rates due to higher recruitment, survival and growth of seedlings, while increased forest edge length was positively associated with population growth rates primarily due to a higher survival of reproductive individuals. Effects were stronger during the first of the two transition intervals studied. The results demonstrate that changes in different landscape structural characteristics may result in opposing effects acting via different vital rates, and highlight the need for integrative analyses to evaluate the effects of rapid landscape transformation on the current and long term plant population dynamics.
|
|
| 8. |
- Valdés, Alicia, et al.
(författare)
-
Direct and plant trait-mediated effects of the local environmental context on butterfly oviposition patterns
- 2018
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 127:6, s. 825-833
-
Tidskriftsartikel (refereegranskat)abstract
- Variation in the intensity of plant-animal interactions over different spatial scales is widespread and might strongly influence fitness and trait selection in plants. Differences in traits among plant individuals have been shown to influence variation in interaction intensities within populations, while differences in environmental factors and community composition are shown to be important for variation over larger scales. However, little is still known about the relative importance of the local environmental context vs. plant traits for the outcome of interactions within plant populations. We investigated how oviposition by the seed-predator butterfly Phengaris alcon on its host plant Gentiana pneumonanthe was related to host plant traits and to local environmental variation, as well as how oviposition patterns translated into effects on host plant fruit set. We considered the local environmental context in terms of height of the surrounding vegetation and abundance of the butterfly's second host, Myrmica ants. The probability of oviposition was higher in plants that were surrounded by lower vegetation, and both the probability of oviposition and the number of eggs increased in early-flowering and tall plants with many flowers in the three study populations. Flowering phenology, shoot height and flower production were, in turn, related to higher surrounding vegetation. Myrmica abundance was correlated with vegetation height, but had no effect on oviposition patterns. Oviposition and subsequent seed predation by the caterpillars strongly reduced host plant fruit set. Our results show that plant-animal interactions are context-dependent not only because the context influences the abundance or the behavior of the animal interactor, but also because it influences the expression of plant traits that affect the outcome of the interaction. The results also demonstrate that heterogeneity in environmental conditions at a very local scale can be important for the outcomes of interactions.
|
|
| 9. |
- Valdés, Alicia, 1982-, et al.
(författare)
-
Microclimate influences plant reproductive performance via an antagonistic interaction
- 2022
-
Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 64, s. 13-29
-
Tidskriftsartikel (refereegranskat)abstract
- Climatic conditions can influence plant reproduction directly, but also via changes in plant traits, interactions with animals, and the surrounding environment. Such indirect effects can often be complex and involve multiple steps including climatic effects on interacting species, and on the context in which these interactions occur. The joint effects of climatic variation and indirect effects in terms of plant-animal interactions have sometimes been assessed at larger spatial scales. However, less is known about how microclimatic variation affects within-population variation in reproductive performance, in spite of that it is becoming increasingly clear that variation in climatic conditions can occur over very short distances. We studied the direct and indirect effects of microclimate on withinpopulation variation in reproductive performance of the plant Gentiana pneumonanthe in presence of the myrmecophagous and seed predator butterfly Phengaris alcon. We found that microclimatic effects on plant performance were mainly indirect, and that effects of temperature and moisture were interactive. The number of seeds per flower of G. pneumonanthe decreased in cold and moist microsites, and these effects were mediated by an increased oviposition by P. alcon in these microsites. The effects of soil temperature and moisture on the incidence of oviposition and plant performance were mediated by effects on plant phenology, density and phenology of neighbouring host plants, and host ant abundance. Plants that flowered earlier and where host ants were more abundant, and especially plants surrounded by fewer and later-flowering neighbours, produced fewer seeds per flower because of a higher incidence of oviposition. Our results demonstrate that effects of microclimatic variation on plant reproductive performance can be mostly indirect and largely mediated by species interactions. These findings highlight that among individual variation in small-scale environmental conditions within populations can cause variation in individual plant performance through multiple pathways.
|
|
| 10. |
- Valdés, Alicia, et al.
(författare)
-
Plant-animal interactions mediate climatic effects on selection on flowering time
- 2021
-
Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 102:9
-
Tidskriftsartikel (refereegranskat)abstract
- Selection on flowering time in plants is often mediated by multiple agents, including climatic conditions and the intensity of mutualistic and antagonistic interactions with animals. These selective agents can have both direct and indirect effects. For example, climate might not only influence phenotypic selection on flowering time directly by affecting plant physiology, but it can also alter selection indirectly by modifying the seasonal activity and relative timing of animals interacting with plants. We used 21 yr of data to identify the drivers of selection on flowering time in the perennial herb Lathyrus vernus, and to examine if antagonistic plant-animal interactions mediate effects of climate on selection. We examined the fitness consequences of vertebrate grazing and predispersal seed predation, and how these effects varied among years and among individuals within years. Although both antagonistic plant-animal interactions had important negative effects on plant fitness, only grazing intensity was consistently related to plant phenology, being higher in early-flowering individuals. Spring temperature influenced the intensity of both plant-animal interactions, as well as the covariance between seed predation and plant phenology. However, only differences in grazing intensity among years were associated with differences in selection on flowering time; the strength of selection for early flowering being stronger in years with lower mean intensity of grazing. Our results illustrate how climatic conditions can influence plant-animal interactions that are important selective agents for plant traits. A broader implication of our findings is that both ecological and evolutionary responses to climatic changes might be indirect, and largely mediated by species interactions.
|
|
