A multi-year experiment shows that lower precipitation predictability encourages plants’ early life stages and enhances population viability

Climate change is a key factor that may cause the extinction of species. The associated reduced weather predictability may alter the survival of plants, especially during their early life stages, when individuals are most fragile. While it is expected that extreme weather events will be highly detrimental for species, the effects of more subtle environmental changes have been little considered. In a four-year experiment on two herbaceous plants, Papaver rhoeas and Onobrychis viciifolia, we manipulated the predictability of precipitation by changing the temporal correlation of precipitation events while maintaining average precipitation constant, leading to more and less predictable treatments. We assessed the effect of predictability on plant viability in terms of seedling emergence, survival, seed production, and population growth rate. We found greater seedling emergence, survival, and population growth for plants experiencing lower intra-seasonal predictability, but more so during early compared to late life stages. Since predictability levels were maintained across four generations, we have also tested whether descendants exhibited transgenerational responses to previous predictability conditions. In P. rhoeas, descendants had increased the seedling emergence compared to ancestors under both treatments, but more so under lower precipitation predictability. However, higher predictability in the late treatment induced higher survival in descendants, showing that these conditions may benefit long-term survival. This experiment highlights the ability of some plants to rapidly exploit environmental resources and increase their survival under less predictable conditions, especially during early life stages. Therefore, this study provides relevant evidence of the survival capacity of some species under current and future short-term environmental alterations

Evidencias experimentales para el conocimiento de los mecanismos de adaptación de las plantas a los cambios ambientales

2 páginasPeer reviewe

Warmer and less variable temperatures favour an accelerated plant phenology of two invasive weeds across sub-Antarctic Macquarie Island

The great plasticity and diverse reproductive strategies of invasive alien plants are widely assumed to contribute to invasion success, even in extreme areas, often displacing native species. In this context, climate change creates new opportunities for biological invasions. Environmental variability and global warming are two of the climatic processes that may promote invasiveness, since alien species modulate their phenology to succeed under these circumstances. We monitored the phenological development (phenological stage advancement) of the two main invasive alien species: Poa annua L. and Cerastium fontanum Baumg. in the sub-Antarctic Macquarie Island during the austral summer period along an altitudinal gradient. We found that higher temperatures lead to increased plant height and accelerated phenological development than lower temperatures in P. annua but found no direct evidence of the latter in C. fontanum. However, increased temperature variability negatively affected the phenological development of both species. Interestingly, despite their different reproductive strategy (rapid and impromptu in P. annua, and more synchronic and gradual in C. fontanum), both species prolifically succeeded in producing seeds at all sites showing the great acclimation of these two alien species even in limiting conditions. Since both alien species in Macquarie Island showed larger size and faster phenology at lower altitudes (i.e. milder conditions), this would indicate a great influence of ameliorating abiotic extremes on alien plant invasive capabilities at environmental extremes. Thus, our results warn of the increasing capabilities under climatic warming scenarios for alien plants to reproduce even at such remote ranges. This highlights the need to reinforce calls for special attention to prevent the spread of these kinds of species to other similar sub-polar areas, where intensive post-introduction management may be difficult or expensive.Field research of LRP was supported by AAS 4158 project of the Australian Antarctic Science Program.LRP was also recipient of a SCAR fellowship. MMS was supported by a FPI PhD Grant (BES-2013-062910) that was funded by the Spanish Ministry of Economy and Competitiveness

Changes in environmental predictability alter a plant's chemical composition and associated ecosystem services

Current climate change alters the frequency and intensity of precipitation events, and the temporal autocorrelation between these events, i.e. their predictability. Little is known about how differences in predictability affect a plant¿s chemical composition, and whether such differences may affect the provided ecosystem services. Here we experimentally tested this question by using a two-factorial field experiment, in which the forage legume Onobrychis viciifolia was exposed to more and less predictable daily (predictability of the summed simulated and natural daily precipitation) and seasonal precipitation over four consecutive years. Using an individual trait-based approach we show that less predictable precipitation led to higher aboveground and root biomass, and to higher nitrogen content in leaves and roots. Consequently, less predictable precipitation led to higher productivity. In contrast, lignin content and the C:N ratio were lower, which favours palatability, digestibility and litter decay. These results indicate that differences in precipitation predictability alter a plant¿s chemical composition, plant-soil interactions, and that less predictable precipitation may improve ecosystem services provided by O. viciifolia, agricultural yields, and even, economic benefits, at least as long as no extreme events occur.Funding was provided by the Spanish Ministry of Economy and Competitiveness (CGL2012-32459, CGL2016-76918 to PSF) and the Swiss National Science Foundation (PPOOP3_128375, PP00P3_152929/1 to PSF). MMS was supported by a PhD grant (BES-2013-062910) financed by the Spanish Ministry of Economy and Competitiveness.Peer Reviewe

Effects of intrinsic environmental predictability on intra-individual and intra-population variability of plant reproductive traits and eco-evolutionary consequence

[Background and Aims]: It is widely accepted that changes in the environment affect mean trait expression, but little is known regarding how the environment shapes intra-individual and intra-population variance. Theory suggests that intra-individual variance might be plastic and under natural selection, rather than reflecting developmental noise, but evidence for this hypothesis is scarce. Here, we experimentally tested whether differences in intrinsic environmental predictability affect intra-individual and intra-population variability of different reproductive traits, and whether intra-individual variability is under selection.[Methods]: Under field-conditions, we subjected Onobrychis viciifolia to more and less predictable precipitation over four generations and four years. We analysed effects on the coefficient of intra-individual (CVi-i) and the coefficient of intra-population variation (CVi-p), assessed whether the coefficients of intra-individual variation (CsVi-i) are under natural selection and tested for transgenerational responses (ancestor environmental effects on offspring).[Key Results]: Less predictable precipitation let to higher CsVi-i and CsVi-p, consistent with plastic responses. The CsVi-i of all studied traits were under consistent stabilizing selection, and precipitation predictability affected the strength of selection and the location of the optimal CVi-i of a single trait. All CsVi-i differed from the optimal CVi-i and the maternal and offspring CVi-i were positively correlated, showing that there was scope for change. Nevertheless, no consistent transgenerational effects were found in any of the three descendant generations, which contrasts with recent studies that detected rapid transgenerational responses in trait means of different plant species. This suggests that changes in intra-individual variability take longer to evolve than changes in trait means, which may explain why high intra-individual variability is maintained, despite the stabilizing selection.[Conclusions]: The results indicate that plastic changes of intra-individual variability are an important determinant of whether plants will be able to cope with changes in environmental predictability induced by the currently observed climatic change.Funding was provided by the Swiss National Foundation (PPOOP3_128375, PP00P3_152929/1 to P.S.F.) and the Spanish Ministry of Economy and Competitiveness, the latter cofinanced by the European Fund for Regional Development, (CGL2012-32459, CGL2016-76918 AEI/FEDER, UE to PSF). M.M.S. was supported by a PhD grant (BES-2013–062910) financed by the Spanish Ministry of Economy and Competitiveness

Effects of intrinsic precipitation‐predictability on root traits, allocation strategies and the selective regimes acting on them

Climate change affects means, variances and the intrinsic predictability of the climate. However, experimental tests of how changes in intrinsic climatic predictability affects plant traits, allocation strategies and the selective regime acting on them are scarce, as well as evidence for the importance of root functional traits to cope with climatic uncertainty. Here, we experimentally manipulated intrinsic daily and inter-seasonal precipitation-predictabilities and tested their effect on root traits, root allocation strategies, the selective regime acting on them, and transgenerational root responses, using a four-year field experiment and Onobrychis viciifolia. More predictable precipitation led to lower root biomass and a lower overall plant performance, and to higher allocation to roots and higher within-root allocation (i.e. allocation to root branching and maximum rooting depth relative to allocation to roots). Differences in intrinsic daily and inter-seasonal predictability induced differences in the strength of selection acting on the studied traits, but did not affect the type of the selective regime, nor the transgenerational responses. The results indicate that higher predictability constrained a plant’s performance, while plants were able to cope with lower predictability. Absence of transgenerational responses in root traits with respect to the predictability treatments, points to slow or no inter-generational changes of root traits in unpredictable habitats. Thus, adjustments in root allocation strategies and changes therein might be key to deal with increasing climatic uncertainty.publishe

Rapid and positive responses of plants to lower precipitation predictability

[EN] Current climate change is characterized by an increase in weather variability, which includes altered means, variance and predictability of weather parameters, and which may affect an organism's ecology and evolution. Few studies have experimentally manipulated the variability of weather parameters, and very little is known about the effects of changes in the intrinsic predictability of weather parameters on living organisms. Here, we experimentally tested the effects of differences in intrinsic precipitation-predictability on two herbaceous plants (Onobrychis viciifolia and Papaver rhoeas). Lower precipitation-predictability led to phenological advance and to an increase in reproductive success, and population growth. Both species exhibited rapid transgenerational responses in phenology and fitness-related traits across four generations that mitigated most effects of precipitation-predictability on fitness proxies of ancestors. Transgenerational responses appeared to be the result of changes in phenotypic plasticity rather than local adaptation. They mainly existed with respect to conditions prevailing during early, but not during late growth, suggesting that responses to differences in predictability during late growth might be more difficult. The results show that lower short-term predictability of precipitation positively affected fitness, rapid transgenerational responses existed and different time scales of predictability (short-term, seasonal and transgenerational predictability) may affect organisms differently. This shows that the time scale of predictability should be considered in evolutionary and ecological theories, and in assessments of the consequences of climate change.Funding was provided by the Spanish Ministry of Economy and Competitiveness (grant no. CGL2012-32459 to P.S.F.), Ministerio de Ciencias, Investigación, y Universidades (grant no. CGL2016-76918 AEI/FEDER, UE to P.S.F.) and the Swiss National Foundation(grant nos. PPOOP3_128375, PP00P3_152929/1 to P.S.F.). M.M.-S.was supported by a PhD grant (grant no. BES-2013-062910) financedby the Spanish Ministry of Economy and Competitiveness and a travel grant of the Universidad Rey Juan Carlo

Assessment of the potential risk of rock-climbing for cliff plant species and natural protected areas of Spain

In recent years, the popularity of rock-climbing has grown tremendously, setting an increasing pressure on cliff habitats. Climbing may be particularly harmful in the Mediterranean biome due to its appropriate environmental conditions for climbing. A few studies have identified the effect of climbing on plant diversity at a small-scale (namely locally or even just in specific climbing areas). However, no studies exist assessing the potential risk of rock-climbing on a broad-scale (e.g., regional or national). The study aims to identify the priority locations and priority cliff plant species in Spain to focus future study efforts. Spain was selected because it is a plant biodiversity hotspot, with a great diversity of endemic and endangered species, and one of the most popular destinations for climbers. We used a geographic information system-based approach to model the spatial concurrence among Spanish climbing areas (and climbing intensity), natural protected areas (NPAs), and distribution of threatened cliff plants (and their IUCN threat category). We found that 53.5% of climbing areas in Spain are located within a NPA, most of them falling into NPAs of medium protection level. We mapped 151 threatened cliff plants, identifying four medium priority Mediterranean locations and eight priority species in which future research efforts should be focused. High-priority study locations are absent in Spain according to our spatial modeling. For the first time on a national scale, this study identifies areas in which climbing represents a potential threat for cliff habitats and threatened plants. These findings contribute to designing field studies on the effects of rock-climbing on Mediterranean cliffs, laying the groundwork for a sustainable, yet challenging, balance between the protection of these unique habitats and rock-climbing

Spatial partitioning of perching on plants by tropical dung beetles depends on body size and leaf characteristics: a sit-and-wait strategy for food location

[1.] Many animals invest a great amount of time and energy foraging.However, the sit-and-wait strategy is a common behaviour, which reduces the cost of moving by using perches. In the case of dung beetles, individuals of many species use leaves as perches. The factors for the selection of these perches are still unknown, but one hypothesis proposes that plant features may be key, creating an ecological animal–plant network.[2.] We identified dung beetles and plant species in a tropical rain forest and measured the height and area of the leaves, and the body length for each species. We fitted linear regression models to test the relationship between the height and area of the leaf and a beetle’s body size. We also analysed the number of perching interactions through a bipartite analysis to quantify the network modularity.[3.] We collected 369 dung beetles of 21 species that were perching on 32 plant species.There were significant differences in the selection of perches related to dung beetle body size and functional group. Larger beetle species selected higher and larger leaves, whereas telecoprids perched on higher leaves than paracoprids.[4.] Our findings show a distinct network of beetle-plant relationships with clear preferences by some dung beetles for particular plant species. The findings also suggest that the processes driving network structure lead to spatial segregation of dung beetle species. In conclusion, sit-and-wait behaviour is a common and apparently effective strategy for foraging, and reduces competition in dung beetles in tropical rain forests.JAN was supported by a Colombian COLCIENCIAS PhD scholarship and MMS was supported by an FPI PhD Grant (BES-2013-062910 from the CGL2012-32459 project)