For many species of conservation significance, multiple factors limit reproduction. In a new study published in AoB PLANTS, Walsh et al. examined the contribution of plant height, number of flowers, number of stems, as well as the joint impacts of mutualists and antagonists on the pollination biology and seed production of the imperiled, deceptive orchid, Cypripedium candidum. They found flowering stem height to be the only morphological feature significant in reproduction, with taller flowering stems simultaneously receiving increased pollination and decreased seed predation. Furthermore they found decreased seed mass in individuals subjected to hand-self pollination treatments. Their results may help explain the factors limiting seed production in other Cypripedium and further emphasize the importance of management in orchid conservation.
Invasive species cause ecological, economic and social impacts and are key drivers of global change. This is the case for the genus Prosopis (mesquite; Fabaceae) where several taxa are among the world’s most damaging invasive species. Prosopis taxa are currently naturalised or invasive in 103 countries and are bioclimatically suitable for many more. There are numerous management practices available to control Prosopis invasions, each with their benefits and costs, however, in most areas management has had only limited success. In a new article published in AoB PLANTS, Shackleton et al. present a global review of Prosopis, focusing on its distribution, impacts, benefits and approaches to management. Key gaps in knowledge and promising options for management are highlighted.
Genome doubling and changes in genome size are fundamental evolutionary processes, with polyploidy being one of the most important forces influencing plant diversification. However, little is currently known about the extent of genome size variation within taxa and the evolutionary forces acting on this variation. Arabidopsis kamchatica has been reported to contain both diploid and tetraploid individuals (2 or 4 copies of every chromosome). In a new study in AoB PLANTS, Wolf et al. found genome size differences among populations, and among populations genome size varied by 7%. However, all sampled A. kamchatica plants from a wide geographic range were tetraploids. This level of intraspecific genome size variation in A. kamchatica is lower than in other Arabidopsis taxa. Due to its close relationship to A. thaliana, A. kamchatica has the potential to be very useful in the study of polyploidy and genome evolution.
Clonal plants are common in frequently flooded habitats because of their resilience to disturbance. In a new study published in AoB PLANTS, Huber et al. investigated whether submergence prior to fragmentation of clones of two clover species reduced survival and regrowth of clonal fragments, and whether these fitness parameters differed between genotypes from highly disturbed river forelands and less disturbed coastal dune slacks. They found that soil flooding severely decreased survival and regrowth, and that plants from the more disturbance-prone habitat were less negatively affected by fragmentation. However, internode size was, surprisingly, often negatively correlated with survival after fragmentation, but positively correlated with regrowth. Apparently, contrasting selection pressures exist on internode size in stoloniferous species growing in disturbed habitats.
The energetic cost of plant organ construction is a functional trait that is useful in understanding carbon investment during growth (e.g., the resource acquisition vs. tissue longevity tradeoff), as well as in response to global change factors like elevated CO2 and N. Despite the enormous importance of roots and rhizomes in acquiring soil resources and responding to global change, construction costs have been studied almost exclusively in leaves. In a new study in AoB PLANTS, the energetic costs of tissue construction were compared in two subspecies of Phragmites australis, the common reed – namely the primary native and introduced lineages in North America. Caplan et al. report that the introduced lineage has lower construction costs than the native under all environmental conditions assessed, driven mainly by its lower cost rhizomes. These results highlight the fact that belowground energetics, which are seldom investigated, can influence the performance advantages that drive many plant invasions. The authors also demonstrate that tissue construction costs in organs not typically assessed can shift with global change, suggesting that they may have increasingly important implications into the future.
AoB PLANTS, the premier open-access journal for plant sciences, is seeking a part-time social media editor to develop features for our website and to expand the journal’s presence on Facebook, Twitter, blogs and other social media outlets, with the general objective of increasing the visibility, influence and reputation of our journal.
The ideal candidate will meet the following criteria:
• a graduate degree in biology
• demonstrated research experience in some area of the plant sciences
• in-depth knowledge of social-media tools and applications
• evidence of social-media publishing experience
For details see http://bit.ly/1wfniSJ. Interested individuals should contact the Chief Editor Hall Cushman (email@example.com) and/or Managing Editor Gail Rice (firstname.lastname@example.org).
Most investigations of plant responses to changes in temperature have focused on a constant increase in temperature. However, changes in fluctuation in temperature, even if the mean temperature is the same, may affect plant growth. In a new article published in AoB PLANTS, Cerasoli et al. tested the effects of weekly warm and then cool moderate (5oC) and large (10oC) fluctuation in temperature (with the same biweekly temperature sum) on plant growth. They found that, while the ratio of photosynthesis to respiration did not change, fluctuations in temperature did increase biomass accumulation and alter biomass allocation. Their findings suggest that, like mean temperature, fluctuation in temperature can significantly impact plant growth.
In recent years, research in invasion biology has focused increasing attention on understanding the role of phenology in shaping plant invasions. Multiple studies have found non-native species that tend to flower distinctly early or late in the growing season, advance more with warming or have shifted earlier with climate change compared to native species. In a new article published in AoB PLANTS, Wolkovich and Cleland review recent evidence that non-native and invasive plant species may have distinct timings of their seasonal life history characteristics (such as date of leaf out or flowering, that is, their phenology) that allow them to establish in new communities. In particular they examine how invasions may be bolstered by the longer growing seasons associated with climate change. Based on current knowledge of plant phenology and growth strategies—especially rapid growing, early-flowering species versus later-flowering species that make slower-return investments in growth—they project optimal periods for invasions across three distinct systems under current climate change scenarios.
Floods have a severe impact on plant performance. In general, crops are flood intolerant and are at an increased risk to flooding events due to global climate change. Given that the human population is expected to increase to approximately 9 billion people by 2050, the need for increased agricultural productivity is self-evident, and this will require a better mechanistic understanding of the interaction between plants and abiotic stresses such as flooding.
In a new article published in AoB PLANTS, Voesenek et al. argue that, in seeking this understanding, we should not restrict research to model species such as rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), as wild plants from flood-prone environments have evolved in frequently flooded environments and therefore possess unique traits that facilitate growth and reproduction during and after flooding stress. Flooding research with these non-model wild plants might help us to identify novel adaptive traits that can be applied to improve flooding tolerance of crops.
Seedling growth rates can have important long-term effects on forest dynamics. Environmental variables such as light availability and edaphic factors can exert a strong influence on seedling growth. The aim of a new article by Offord et al., published in AoB PLANTS, was to uncover the drivers of seedling growth in a rare rainforest conifer. Wollemia nobilis is limited to canyons, characterized by deeply shaded understories and acid soils. In a glasshouse experiment, the authors grew seedlings at a range of pH and light levels. Growth increased with increasing light, and was higher at low pH, regardless of light. The number of stems, however, was greatest in lower light. Thus Wollemia nobilis seedlings may vary their architecture – growing up when light is high, and growing out when light is lower. Nevertheless, low light is likely the key limitation of W. nobilis growth in the wild.