Extensive contemporary pollen-mediated gene flow in two herb species, Ranunculus bulbosus and Trifolium montanum, along an altitudinal gradient in a meadow landscape

Background and Aims Genetic connectivity between plant populations allows for exchange and dispersal of adaptive genes, which can facilitate plant population persistence particularly in rapidly changing environments. Methods Patterns of historic gene flow, flowering phenology and contemporary pollen flow were investigated in two common herbs, Ranunculus bulbosus and Trifolium montanum, along an altitudinal gradient of 1200-1800 m a.s.l. over a distance of 1 km among five alpine meadows in Switzerland. Key Results Historic gene flow was extensive, as revealed by Fst values of 0·01 and 0·007 in R. bulbosus and T. montanum, respectively, by similar levels of allelic richness among meadows and by the grouping of all individuals into one genetic cluster. Our data suggest contemporary pollen flow is not limited across altitudes in either species but is more pronounced in T. montanum, as indicated by the differential decay of among-sibships correlated paternity with increasing spatial distance. Flowering phenology among meadows was not a barrier to pollen flow in T. montanum, as the large overlap between meadow pairs was consistent with the extensive pollen flow. The smaller flowering overlap among R. bulbosus meadows might explain the slightly more limited pollen flow detected. Conclusions High levels of pollen flow among altitudes in both R. bulbosus and T. montanum should facilitate exchange of genes which may enhance adaptive responses to rapid climate chang

Landscape Composition Has Limited Impact on Local Genetic Structure in Mountain Clover, Trifolium montanum L

Semi-dry grasslands in the European Alps have been increasingly fragmented over the last 150 years. Few studies have investigated the implications of landscape configuration for genetic structure and gene flow among remnant habitat patches. Conservation management of semi-dry grassland plants rarely accounts for possible effects of major landscape elements, such as forest patches, as barriers to gene flow and dispersal via seed and pollen, despite their potential importance for biodiversity conservation. Using 1416 individuals from 61 sampling sites across 2 valleys in South-Eastern Switzerland and Amplified fragment length polymorphism (AFLP) fingerprints, we applied a spatial strip and a circle approach to determine the impact of different landscape elements on genetic differentiation in the semi-dry grassland herb Trifolium montanum (mountain clover). Overall genetic differentiation among sampling sites was low (overall F ST = 0.044). Forest area had no effect on gene flow at the landscape scale, but area of semi-dry grassland, the potential habitat of T. montanum, road area, and altitude influenced genetic differentiation among sampling sites. The observed pattern of genetic differentiation suggests that a future increase in forest area, due to land use abandonment, at least in the short term, are unlikely to directly impact patterns of genetic variation in T. montanu

Are patterns of fine-scale spatial genetic structure consistent between sites within tropical tree species?

JRS was funded by the Swiss National Science Foundation (SNF) (http://www.snf.ch/en/Pages/default.aspx) grant number PDFMP3_132479 / 1 awarded to JG. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Genetic diversity affects seedling survival but not growth or seed germination in the Bornean endemic dipterocarp Parashorea tomentella

Background: Logging and habitat fragmentation of tropical rain forests may disrupt patterns of gene flow and genetic diversity. Consequently, inbreeding in tree populations may reduce fitness and increase extinction risks, especially among species that are predominantly outcrossing, dependent on biotic pollination and/or display limited seed dispersal such as species of the Dipterocarpaceae. Aims: To test the hypothesis that heterozygosity of individual progeny affects their likelihood of germination and the growth and survival of seedlings. Methods: Standardised measure of multilocus heterozygosity (sMLH) was estimated from seven microsatellite loci for individual progeny collected from 18 mother trees of the large dipterocarp Parashorea tomentella. The relationships among sMLH, germination and seedling growth and survival were determined for the progeny. Results: Seedling survival over 18 months increased with greater sMLH and fresh fruit weight. This result was expressed under all experimentally controlled combinations of light and nutrient availability in the nursery and in the shaded understorey of primary forest where survival overall was much lower than in the nursery. sMLH did not affect the probability of germination or seedling growth rate in any experimental treatment. Conclusions: These results provide evidence that reduced heterozygosity is associated with reduced seedling survival in a tropical forest tree species

Impacts of an extreme precipitation event on dipterocarp mortality and habitat filtering in a Bornean tropical rainforest

The frequency of extreme precipitation events is predicted to increase in some tropical regions in response to global climate change, but the impacts of this form of disturbance on the structure and dynamics of tropical tree communities across heterogeneous landscapes remain understudied. We determined the effects of an extreme precipitation event (EPE) in July 2006 on mortality of dipterocarps on a 68 ha permanent inventory plot in Sepilok Forest Reserve, Sabah. For stems ≥30 cm dbh, 12 of the 15 species of Dipterocarpaceae on this plot have significant positive and/or negative associations to habitats defined by topography and soil type. Short-term mortality induced by the EPE was much greater for individuals growing on the alluvial floodplain (13.7%) than in the mudstone (1.4%) or sandstone (0.0%) habitats, but mortality of dipterocarps did not differ among these habitats in the subsequent 5-yr interval. The likelihood of mortality in response to the EPE was highest for a small group of fast growing dipterocarps that possess low wood density and a strong association to the alluvial forest habitat. This group of species represents a high percentage of dipterocarp individuals but a low proportion of dipterocarp diversity in this habitat. We conclude that disturbance induced by high rainfall events contributes to the episodic nature of tropical forest dynamics, and that increases in the frequency of these events would disproportionately impact low-lying alluvial forest environments and some of the species growing in them

Diversity under threat: Connecting genetic diversity and threat mapping to set conservation priorities for Juglans regia L. populations in Central Asia

Central Asia is an important center of diversity for common walnut (Juglans regia L.). We characterized the genetic diversity of 21 wild and cultivated populations across Kyrgyzstan, Tajikistan and Uzbekistan. A complete threat assessment was performed evaluating the short-term threats from overexploitation, overgrazing, landslides, and fragmentation as well as long-term threats from climate change. Based on key indicators of genetic diversity and threat magnitude, we developed an approach to identify wild populations for priority conservation and defined appropriate measures to conserve their genetic diversity based on the specific threat magnitudes. We propose (i) ex-situ conservation in areas with ‘severe threat level’ due to climate change and (ii) in-situ conservation in areas with ‘minor threat level’ due to climate change. In addition, we suggest (iii) assisted natural regeneration in areas where ‘minor threat levels’ from climate change coincide with ‘severe threat levels’ from one or more short-term threats. Our research shows high levels of genetic diversity as well as high threat levels in the walnut populations examined across three countries. Overgrazing and overexploitation were identified as the two most important threats whereas climate changed turned out to be of minor concern in the near future. Four out of the five populations selected for priority conservation are severely threatened: Kara-Alma (KGP3) and Sariosiyo (UZP4) by overexploitation and overgrazing, Vanj (TJP2) by landslides and fragmentation and Bostanlyk_2 (UZP2) by overexploitation. Only the Baljuvon population (TJP4) in Tajikistan shows minor threat levels in the short and long term. Thus, for all five priority populations the most appropriate conservation approach appears to be in-situ conservation. Spontaneous natural regeneration should be sufficient to ensure the long-term survival of the Baljuvon population (TJP4), while for the other four priority populations assisted natural regeneration may be needed. This network of five sites represents the minimum number of conservation areas for wild walnut in the three countries that should be established to capture a significant amount of the species genetic diversity. Conservation efforts could be extended to home gardens, which are a valuable genetic reservoir for the wild diversity found in the region

Ecological implications of a flower size/number trade-off in tropical forest trees

Peer reviewedPublisher PD

Achieving sustainable quality in maternity services – using audit of incontinence and dyspareunia to identify shortfalls in meeting standards

BACKGROUND: Some complications of childbirth (for example, faecal incontinence) are a source of social embarrassment for women, and are often under reported. Therefore, it was felt important to determine levels of complications (against established standards) and to consider obstetric measures aimed at reducing them. METHODS: Clinical information was collected on 1036 primiparous women delivering at North and South Staffordshire Acute and Community Trusts over a 5-month period in 1997. A questionnaire was sent to 970 women which included self-assessment of levels of incontinence and dyspareunia prior to pregnancy, at 6 weeks post delivery and 9 to 14 months post delivery. RESULTS: The response rate was 48%(470/970). Relatively high levels of obstetric interventions were found. In addition, the rates of instrumental deliveries differed between the two hospitals. The highest rates of postnatal symptoms had occurred at 6 weeks, but for many women problems were still present at the time of the survey. At 9–14 months high rates of dyspareunia (29%(102/347)) and urinary incontinence (35%(133/382)) were reported. Seventeen women (4%) complained of faecal incontinence at this time. Similar rates of urinary incontinence and dyspareunia were seen regardless of mode of delivery. CONCLUSION: Further work should be undertaken to reduce the obstetric interventions, especially instrumental deliveries. Improvements in a number of areas of care should be undertaken, including improved patient information, improved professional communication and improved professional recognition and management of third degree tears. It is likely that these measures would lead to a reduction in incontinence and dyspareunia after childbirth

Tapping into the environmental co-benefits of improved tropical forages for an agroecological transformation of livestock production systems

Livestock are critical for incomes, livelihoods, nutrition and ecosystems management throughout the global South. Livestock production and the consumption of livestock-based foods such as meat, cheese, and milk is, however, under global scrutiny for its contribution to global warming, deforestation, biodiversity loss, water use, pollution, and land/soil degradation. This paper argues that, although the environmental footprint of livestock production presents a real threat to planetary sustainability, also in the global south, this is highly contextual. Under certain context-specific management regimes livestock can deliver multiple benefits for people and planet. We provide evidence that a move toward sustainable intensification of livestock production is possible and could mitigate negative environmental impacts and even provide critical ecosystem services, such as improved soil health, carbon sequestration, and enhanced biodiversity on farms. The use of cultivated forages, many improved through selection or breeding and including grasses, legumes and trees, in integrated crop-tree-livestock systems is proposed as a stepping stone toward agroecological transformation. We introduce cultivated forages, explain their multi-functionality and provide an overview of where and to what extent the forages have been applied and how this has benefited people and the planet alike. We then examine their potential to contribute to the 13 principles of agroecology and find that integrating cultivated forages in mixed crop-tree-livestock systems follows a wide range of agroecological principles and increases the sustainability of livestock production across the globe. More research is, however, needed at the food system scale to fully understand the role of forages in the sociological and process aspects of agroecology. We make the case for further genetic improvement of cultivated forages and strong multi-disciplinary systems research to strengthen our understanding of the multidimensional impacts of forages and for managing agro-environmental trade-offs. We finish with a call for action, for the agroecological and livestock research and development communities to improve communication and join hands for a sustainable agri-food system transformation

Are tree seed systems for forest landscape restoration fit for purpose? An analysis of four Asian countries

High-quality, suitably adapted tree seed at volume is a key component for the implementation and long-term success of forest landscape restoration (FLR). We analysed the tree seed systems in four Asian countries—the Philippines, Indonesia, Malaysia and India—which have committed to restore in total over 47.5 million hectares of degraded lands by 2030. We assessed the national seed systems using an established indicator framework, literature review and expert surveys and interviews. Additionally, we surveyed 61 FLR practitioners about their challenges in acquiring seed to understand how the strengths and weaknesses identified at the national level were reflected in FLR projects on the ground. Identified key constraints common to the studied countries are (i) a mismatch between the growing demand for priority native species and the limited seed supply in terms of quantity and quality, (ii) lack of effective quality control for seed of native species and (iii) lack of information about the effects of climate change on native species to guide species selection and seed sourcing and to improve the resilience of restored ecosystems. We discuss options to strengthen seed systems for native tree species both in terms of quality and volume to enable them to effectively respond to the national FLR commitments and make recommendations on promising technical solutions