An integrative study of island diversification: Insights from the endemic Haemodracon geckos of the Socotra Archipelago

Tamar K., Simó-Riudalbas M., Garcia-Porta J., Santos X., Llorente G., Vasconcelos R., Carranza S. (2019) An integrative study of island diversification: Insights from the endemic Haemodracon geckos of the Socotra Archipelago. Molecular Phylogenetics and Evolution. 133: 166-175.
Link
Doi: 10.1016/j.ympev.2019.01.009

Abstract:

The Socotra Archipelago in the Arabian Sea is considered one of the most geo-politically isolated landforms on earth and a center of endemism. The archipelago is located at the western edge of the Indian Ocean and comprises four islands: Socotra, Darsa, Samha, and Abd al Kuri. Here we provide an integrative study on Haemodracon geckos, the sole genus of geckos strictly endemic to the archipelago. The sympatric distribution of Haemodracon riebeckii and H. trachyrhinus on Socotra Island provides a unique opportunity to explore evolutionary relationships and speciation patterns, examining the interplay between possible sympatric and allopatric scenarios. We used molecular data for phylogenetic inference, species delimitation analyses, and to infer the diversification timeframe. Multivariate statistics were used to analyze morphological data. Ecological comparisons were explored for macro-niches using species distribution models and observations were used for micro-habitat use. Haemodracon species exhibit great levels of intraspecific genetic diversity. Our calibration estimates revealed that Haemodracon diverged from its closest relative, the mainland genus Asaccus, in the Eocene, before the detachment of the archipelago. The two Haemodracon species diversified in situ on Socotra Island during the Middle Miocene, after the archipelago's isolation, into the two reciprocally monophyletic recognized species. Their divergence is associated mostly with remarkable body size differences and micro-habitat segregation, with low levels of climatic and body shape divergences within their sympatric distributions. These results display how ecological, sympatric speciation, and allopatric speciation followed by secondary contact, may both have varying roles at different evolutionary phases. © 2019 Elsevier Inc.

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Effects of boom and bust grazing management on vegetation and health of beef cattle used for wildfire prevention in a Mediterranean forest

Teruel-Coll M., Pareja J., Bartolomé J., Serrano E., Mentaberre G., Cuenca R., Espunyes J., Pauné F., Calleja J.A. (2019) Effects of boom and bust grazing management on vegetation and health of beef cattle used for wildfire prevention in a Mediterranean forest. Science of the Total Environment. 665: 18-22.
Link
Doi: 10.1016/j.scitotenv.2019.02.037

Abstract:

Humans and wildfires have historically driven landscape structure in the Mediterranean basin. The Iberian Peninsula is not an exception to that rule, and therefore, farmers, researchers, and governments seek alternative tools to minimize the loss of biodiversity and wildfire risks. Extensive livestock including beef cattle is currently promoted as a suitable management tool by European agro-environmental policies yet pieces of evidence exist regarding the reciprocal effects between cows and Mediterranean woody vegetation. In this work, we performed a field manipulation to evaluate whether free-ranging beef cattle without supplementary feeding, at high density (2 livestock units (LU)/ha) for a short period of time i.e. “boom and bust grazing” management, are able to adapt their grazing preferences to the Mediterranean woody vegetation without health impairment, and prevent from bush encroachment and wildfires. For our purposes, a native herd of 14 adult cows was kept captive without supplementary feeding in a 14 ha enclosure covered by Mediterranean vegetation for two months (April–June 2016). Plant and cattle fecal and blood samples were collected to assess diet composition (plant cuticle microhistological analysis), fecal nitrogen and protein contents of consumed plants, and the nutritional status (non-esterified fatty acids) of cattle. Our results showed that cattle adapted their feeding habits toward a more woody diet including potentially flammable taxa but with some detrimental effects on health status. Hence, cattle cannot control woody vegetation for long periods of time without supplementary feeding. Further research should be oriented to explore other alternative approaches to minimize the health impairment of cattle used for control flammable vegetation in Mediterranean regions. © 2019

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Traditional plant functional groups explain variation in economic but not size-related traits across the tundra biome

Thomas H.J.D., Myers-Smith I.H., Bjorkman A.D., Elmendorf S.C., Blok D., Cornelissen J.H.C., Forbes B.C., Hollister R.D., Normand S., Prevéy J.S., Rixen C., Schaepman-Strub G., Wilmking M., Wipf S., Cornwell W.K., Kattge J., Goetz S.J., Guay K.C., Alatalo J.M., Anadon-Rosell A., Angers-Blondin S., Berner L.T., Björk R.G., Buchwal A., Buras A., Carbognani M., Christie K., Siegwart Collier L., Cooper E.J., Eskelinen A., Frei E.R., Grau O., Grogan P., Hallinger M., Heijmans M.M.P.D., Hermanutz L., Hudson J.M.G., Hülber K., Iturrate-Garcia M., Iversen C.M., Jaroszynska F., Johnstone J.F., Kaarlejärvi E., Kulonen A., Lamarque L.J., Lévesque E., Little C.J., Michelsen A., Milbau A., Nabe-Nielsen J., Nielsen S.S., Ninot J.M., Oberbauer S.F., Olofsson J., Onipchenko V.G., Petraglia A., Rumpf S.B., Semenchuk P.R., Soudzilovskaia N.A., Spasojevic M.J., Speed J.D.M., Tape K.D., te Beest M., Tomaselli M., Trant A., Treier U.A., Venn S., Vowles T., Weijers S., Zamin T., Atkin O.K., Bahn M., Blonder B., Campetella G., Cerabolini B.E.L., Chapin III F.S., Dainese M., de Vries F.T., Díaz S., Green W., Jackson R.B., Manning P., Niinemets Ü., Ozinga W.A., Peñuelas J., Reich P.B., Schamp B., Sheremetev S., van Bodegom P.M. (2019) Traditional plant functional groups explain variation in economic but not size-related traits across the tundra biome. Global Ecology and Biogeography. 28: 78-95.
Link
Doi: 10.1111/geb.12783

Abstract:

Aim: Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits. Location: Tundra biome. Time period: Data collected between 1964 and 2016. Major taxa studied: 295 tundra vascular plant species. Methods: We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits. Results: Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression. Main conclusions: Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling. © 2018 The Authors Global Ecology and Biogeography Published by John Wiley & Sons Ltd

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Hybrid spatiotemporal simulation of future changes in open wetlands: A study of the Abitibi-Témiscamingue region, Québec, Canada

Tiné M., Perez L., Molowny-Horas R. (2019) Hybrid spatiotemporal simulation of future changes in open wetlands: A study of the Abitibi-Témiscamingue region, Québec, Canada. International Journal of Applied Earth Observation and Geoinformation. 74: 302-313.
Link
Doi: 10.1016/j.jag.2018.10.001

Abstract:

Among the most productive ecosystems around the world, wetlands support a wide range of biodiversity such as waterfowl, fish, amphibians, plants and many other species. They also provide ecosystem services that play important roles in relation to nutrient cycling, climate mitigation and adaptation, as well as food security. In this research, we examined and projected the spatiotemporal trends of change in open wetlands by coupling logistic regression, Markov chain methods and a multi-objective land allocation model into a hybrid geosimulation model. To study the changes in open wetlands we used multi-temporal land cover information interpreted from LANDSAT images (1985, 1995, and 2005). We predicted future spatial distributions of open wetlands in the administrative region of Abitibi-Témiscamingue, Quebec, Canada for 2015, 2025, 2035, 2045 and 2055. A comparison and assessment of the model's outcomes were performed using map-comparison techniques as well as landscape metrics. Change analysis between 1985 and 2005 showed an increase of about 63% in open wetlands, while simulation results indicated that this tendency would persist into 2055 with a continuous augmentation of open wetlands in the region. The spatial distribution of predicted trends in open wetlands could provide support to local biodiversity assessments, management and conservation planning of the open wetlands in Quebec, Canada. © 2018 Elsevier B.V.

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Variance in biomass-allocation fractions is explained by distribution in European trees

Veresoglou S.D., Peñuelas J. (2019) Variance in biomass-allocation fractions is explained by distribution in European trees. New Phytologist. 222: 1352-1363.
Link
Doi: 10.1111/nph.15686

Abstract:

Intraspecific variability in ecological traits confers the ability of a species to adapt to an ever-changing environment. Fractions of biomass allocation in plants (BAFs) represent both ecological traits and direct expressions of investment strategies and so have important implications on plant fitness, particularly under current global change. We combined data on BAFs of trees in > 10 000 forest plots with their distributions in Europe. We aimed to test whether plant species with wider distributions have more or less variable intraspecific variance of the BAFs foliage–woody biomass and shoot–root ratios than species with limited distribution. Irrespective of corrections for tree age and phylogenetic relatedness, the standard deviation in BAFs was up to three times higher in species with the most extensive distributions than in those with the least extensive distribution due to a higher genetic diversity. Variance in BAFs also increased with latitude. We show that a combination of 36% tree genetic diversity and 64% environmental variability explains variance in BAFs and implies that changes in genetic diversity occur quickly. Genetic diversity should thus play a key role in regulating species responses to future climate change. Loss of habitat, even if transient, could induce a loss of genetic diversity and hinder species survival. © 2019 The Authors. New Phytologist © 2019 New Phytologist Trust

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Refining predictions of population decline at species' rear edges

Vilà-Cabrera A., Premoli A.C., Jump A.S. (2019) Refining predictions of population decline at species' rear edges. Global Change Biology. 25: 1549-1560.
Link
Doi: 10.1111/gcb.14597

Abstract:

According to broad-scale application of biogeographical theory, widespread retractions of species' rear edges should be seen in response to ongoing climate change. This prediction rests on the assumption that rear edge populations are “marginal” since they occur at the limit of the species' ecological tolerance and are expected to decline in performance as climate warming pushes them to extirpation. However, conflicts between observations and predictions are increasingly accumulating and little progress has been made in explaining this disparity. We argue that a revision of the concept of marginality is necessary, together with explicit testing of population decline, which is increasingly possible as data availability improves. Such action should be based on taking the population perspective across a species' rear edge, encompassing the ecological, geographical and genetic dimensions of marginality. Refining our understanding of rear edge populations is essential to advance our ability to monitor, predict and plan for the impacts of environmental change on species range dynamics. © 2019 John Wiley & Sons Ltd

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Responses of greenhouse-gas emissions to land-use change from rice to jasmine production in subtropical China

Wang C., Li X., Min Q., Wang W., Sardans J., Zeng C., Tong C., Peñuelas J. (2019) Responses of greenhouse-gas emissions to land-use change from rice to jasmine production in subtropical China. Atmospheric Environment. 201: 391-401.
Link
Doi: 10.1016/j.atmosenv.2018.12.032

Abstract:

We studied the impacts of an increasingly common change in land use from paddy field to jasmine fields on the emission of greenhouse gases (GHGs), which have supposed the transformation of more than 1200 ha only in the last decade in the surroundings of Fuzhou city in response to economic changes. The possible increases that this can suppose constitutes and environmental concern in China. We studied areas dedicated to rice crop that have been partially converted to jasmine cultivation with some parts still kept as rice fields. Emissions of CO2, CH4 and N2O varied significantly among the seasons. CO2 and CH4 cumulative emissions and the global-warming potential (GWP) of these emissions were significantly lower in the jasmine than the paddy field. N2O emission, N2O cumulative emission, however, were higher in the jasmine than the paddy field, despite in some concrete studied periods the differences were not statistically significant. The total decrease in GHG emissions from the conversion from rice to jasmine production was strongly influenced by the indirect effects of various changes in soil conditions. The expected changes due to the great differences in water and fertilization use and management and organic matter input to soil between these two crops were in great part due to modified soil traits. According to structural equation models, the strong direct effects of the change from rice to Jasmine crop reducing the emissions of CO2 and N2O were partially decreased by the indirect effects of crop type change decreasing soil pH and soil [Fe2+] for CO2 emissions and by decreasing soil salinity and soil [Fe3+] for N2O emissions. The negative effects of the crop conversion on CH4 emissions were mostly due to the globally negative indirect effects on soil conditions, by decreases in soil salinity, water content and [Fe2+]. Soil salinity, water content, pH, [Fe2+], [Fe3+] and [total Fe] were significantly lower in the jasmine than the paddy field, but temperature had the opposite pattern. CO2 emissions were generally correlated positively with salinity, temperature, and water content and negatively with [Fe3+] and [total Fe] in both fields. CH4 emissions were positively correlated with salinity, temperature, water content and pH in both fields. N2O emissions were positively correlated with temperature and were negatively correlated with water content, pH, [Fe2+], [Fe3+] and [total Fe] in both fields. CO2 was the most important GHG for the GWPs, and the total GWP was significantly lower for the jasmine than for the rice cropland field. The change in the land use in this area of paddy fields will decreased the global GHG emission, and the effect on the GWPs was mostly due to changes in soil properties. © 2018 Elsevier Ltd

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Optimal coupling of straw and synthetic fertilizers incorporation on soil properties, active Fe dynamics, and green house gas emission in Jasminum sambac (L.) field in southeastern China

Wang C., Min Q., Abid A.A., Sardans J., Wu H., Lai D.Y.F., Peñuelas J., Wang W. (2019) Optimal coupling of straw and synthetic fertilizers incorporation on soil properties, active Fe dynamics, and green house gas emission in Jasminum sambac (L.) field in southeastern China. Sustainability (Switzerland). 11: 0-0.
Link
Doi: 10.3390/su11041092

Abstract:

In agriculture, synthetic fertilizers have played a key role in enhancing food production and keeping the world's population adequately fed. China's participation is essential to global efforts in reducing greenhouse gas (GHG) emissions because it is the largest producer and consumer of synthetic fertilizers. A field experiment was conducted in a Jasminum sambac (L.) field to evaluate the impact different doses of fertilizers (half, standard, and double) and their combination with straw on ecosystem (including crop plants and soil) GHG emissions. The results showed that in comparison with the control or straw treatments, the straw + standard fertilizer treatment increased the soil water content. The fertilizer treatments decreased the soil pH, but the straw and combination treatments, especially the straw + standard fertilizer treatment, had higher soil pH in comparison with the fertilizer treatment. The active soil Fe (Fe 2+ and Fe 3+ ) concentration was slightly increased in the straw + standard fertilizer treatment in comparison with the control. Moreover, fertilizer increased the CO 2 emission, and we detected a positive interaction between the straw application and the double fertilization dose that increased CO 2 emission, but the straw + standard fertilizer treatment decreased it. Fertilizer decreased CH 4 and N 2 O emissions, but when straw and fertilizer treatments were applied together, this increased CH 4 and N 2 O emissions. Overall, considering the soil properties and GHG emissions, the straw + standard fertilizer treatment was the best method to enhance soil water retention capacity, improve soil acid, and mitigate greenhouse gas emissions for sustainable management of J. sambac dry croplands. © 2019 by the authors.

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The response of stocks of C, N, and P to plant invasion in the coastal wetlands of China

Wang W., Sardans J., Wang C., Zeng C., Tong C., Chen G., Huang J., Pan H., Peguero G., Vallicrosa H., Peñuelas J. (2019) The response of stocks of C, N, and P to plant invasion in the coastal wetlands of China. Global Change Biology. 25: 733-743.
Link
Doi: 10.1111/gcb.14491

Abstract:

The increasing success of invasive plant species in wetland areas can threaten their capacity to store carbon, nitrogen, and phosphorus (C, N, and P). Here, we have investigated the relationships between the different stocks of soil organic carbon (SOC), and total C, N, and P pools in the plant–soil system from eight different wetland areas across the South-East coast of China, where the invasive tallgrass Spartina alterniflora has replaced the native tall grasses Phragmites australis and the mangrove communities, originally dominated by the native species Kandelia obovata and Avicennia marina. The invasive success of Spartina alterniflora replacing Phragmites australis did not greatly influence soil traits, biomass accumulation or plant–soil C and N storing capacity. However, the resulting higher ability to store P in both soil and standing plant biomass (approximately more than 70 and 15 kg P by ha, respectively) in the invasive than in the native tall grass communities suggesting the possibility of a decrease in the ecosystem N:P ratio with future consequences to below- and aboveground trophic chains. The results also showed that a future advance in the native mangrove replacement by Spartina alterniflora could constitute a serious environmental problem. This includes enrichment of sand in the soil, with the consequent loss of nutrient retention capacity, as well as a sharp decrease in the stocks of C (2.6 and 2.2 t C ha-1 in soil and stand biomass, respectively), N, and P in the plant–soil system. This should be associated with a worsening of the water quality by aggravating potential eutrophication processes. Moreover, the loss of carbon and nutrient decreases the potential overall fertility of the system, strongly hampering the reestablishment of woody mangrove communities in the future. © 2018 John Wiley & Sons Ltd

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Policy-driven monitoring and evaluation: Does it support adaptive management of socio-ecological systems?

Waylen K.A., Blackstock K.L., van Hulst F.J., Damian C., Horváth F., Johnson R.K., Kanka R., Külvik M., Macleod C.J.A., Meissner K., Oprina-Pavelescu M.M., Pino J., Primmer E., Rîșnoveanu G., Šatalová B., Silander J., Špulerová J., Suškevičs M., Van Uytvanck J. (2019) Policy-driven monitoring and evaluation: Does it support adaptive management of socio-ecological systems?. Science of the Total Environment. 662: 373-384.
Link
Doi: 10.1016/j.scitotenv.2018.12.462

Abstract:

Inadequate Monitoring and Evaluation (M&E) is often thought to hinder adaptive management of socio-ecological systems. A key influence on environmental management practices are environmental policies: however, their consequences for M&E practices have not been well-examined. We examine three policy areas - the Water Framework Directive, the Natura 2000 Directives, and the Agri-Environment Schemes of the Common Agricultural Policy - whose statutory requirements influence how the environment is managed and monitored across Europe. We use a comparative approach to examine what is monitored, how monitoring is carried out, and how results are used to update management, based on publicly available documentation across nine regional and national cases. The requirements and guidelines of these policies have provided significant impetus for monitoring: however, we find this policy-driven M&E usually does not match the ideals of what is needed to inform adaptive management. There is a tendency to focus on understanding state and trends rather than tracking the effect of interventions; a focus on specific biotic and abiotic indicators at the expense of understanding system functions and processes, especially social components; and limited attention to how context affects systems, though this is sometimes considered via secondary data. The resulting data are sometimes publicly-accessible, but it is rarely clear if and how these influence decisions at any level, whether this be in the original policy itself or at the level of measures such as site management plans. Adjustments to policy-driven M&E could better enable learning for adaptive management, by reconsidering what supports a balanced understanding of socio-ecological systems and decision-making. Useful strategies include making more use of secondary data, and more transparency in data-sharing and decision-making. Several countries and policy areas already offer useful examples. Such changes are essential given the influence of policy, and the urgency of enabling adaptive management to safeguard socio-ecological systems. © 2019 The Authors

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