Conservation Traps and Long-Term Species Persistence in Human-Dominated Systems

Cardador L., Brotons L., Mougeot F., Giralt D., Bota G., Pomarol M., Arroyo B. (2015) Conservation Traps and Long-Term Species Persistence in Human-Dominated Systems. Conservation Letters. : 0-0.
Link
Doi: 10.1111/conl.12160

Abstract:

Major conservation efforts in human-dominated systems, such as farmland, have focused on the establishment of subsidies and compensation promoting low-impact management practices to reverse the impacts of conservation threats in the short term (reactive approaches). In this study, we discuss how a different way of framing conservation policy (proactive approaches) could lead to fundamentally different long-term conservation outcomes. We define proactive approaches as those not necessarily including measures directly addressing the threats affecting biodiversity, but promoting transitions from current scenarios in which species are threatened to new states in which the threat is no longer present. We illustrate reactive and proactive approaches using as a case study two contrasting conservation frameworks for a vulnerable farmland bird, the Montagu's harrier (Circus pygargus) in northeastern Spain. This example shows that reactive approaches can lead to "conservation traps," which we defined as situations where the application of biologically focused actions in response to conservation problems results in an unsustainable need to perpetuate the implementation of those actions. Our aim is to offer a fresh perspective on biodiversity conservation in human-dominated systems and to stimulate alternative, more holistic approaches in conservation promoting transitions to new states not requiring long-term active and costly conservation action. © 2015 The uthors.

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Tools for exploring habitat suitability for steppe birds under land use change scenarios

Cardador L., Caceres M.D., Giralt D., Bota G., Aquilue N., Arroyo B., Mougeot F., Cantero-Martinez C., Viladomiu L., Rosell J., Casas F., Estrada A., Alvaro-Fuentes J., Brotons L. (2015) Tools for exploring habitat suitability for steppe birds under land use change scenarios. Agriculture, Ecosystems and Environment. 200: 119-125.
Link
Doi: 10.1016/j.agee.2014.11.013

Abstract:

In this study, scenario development based on changes in key socioeconomic drivers (namely, the prices of conventional food products, rural development policies and agro-environmental regulations) was used together with resource-based habitat suitability models to develop plausible visions of future pathways of agricultural land use and evaluate their potential consequences on conservation of target species. Analyses focused on three steppe bird species in a protected Natura 2000 area, located in the Iberian Peninsula. Our results showed that changes in land use composition under different scenarios can have important effects on habitat suitability, but that the size of those effects would vary depending on species-specific requirements and spatial distribution of land use changes. Positive effects of some new crops in the study area (grain legumes and aromatic plants) on studied species were suggested by our analyses. A positive effect of aggregation of land use changes was also found for two of the studied species. Scenario building and forecasting using transferable inter-disciplinary knowledge can therefore improve our capability to anticipate future changes and provide timely advice towards long-term conservation planning in agricultural systems. © 2014 Elsevier B.V.

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European wilderness in a time of farmland abandonment

Ceauşu S., Carver S., Verburg P.H., Kuechly H.U., Hölker F., Brotons L., Pereira H.M. (2015) European wilderness in a time of farmland abandonment. Rewilding European Landscapes. : 25-46.
Link
Doi: 10.1007/978-3-319-12039-3_2

Abstract:

Wilderness is a multidimensional concept that has evolved from an aesthetic idea to a science-based conservation approach. We analyze here several subjective and ecological dimensions of wilderness in Europe: Human access from roads and settlements, impact of artificial night light, deviation from potential natural vegetation and proportion of harvested primary productivity. As expected, high wilderness in Europe is concentrated mainly in low primary productivity areas at high latitudes and in mountainous regions. The use of various wilderness metrics also reveals additional aspects, allowing the identification of regional differences in the types of human impact and a better understanding of future modifications of wilderness values in the context of land-use change. This is because farmland abandonment in the next decades is projected to occur especially at intermediate wilderness values in marginal agricultural landscapes, and thus can release additional areas for wild ecosystems. Although the subjective wilderness experience will likely improve at a slower pace due to the long-term persistence of infrastructures, the ecological effects of higher resource availability and landscape connectivity will have direct positive impacts on wildlife. Positive correlation between megafauna species richness and wilderness indicate that they spatially coincide and for abandoned areas close to high wilderness areas, these species can provide source populations for the recovery of the European biota. Challenges remain in bringing together different views on rewilding and in deciding the best management approach for expanding wilderness on the continent. However the prospects are positive for the growth of self-regulating ecosystems, natural ecological processes and the wilderness experience in Europe. © The Author(s) 2015.

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Contemporary evolution of an invasive plant is associated with climate but not with herbivory

Colomer-Ventura F., Martínez-Vilalta J., Zuccarini P., Escolà A., Armengot L., Castells E. (2015) Contemporary evolution of an invasive plant is associated with climate but not with herbivory. Functional Ecology. 29: 1475-1485.
Link
Doi: 10.1111/1365-2435.12463

Abstract:

Divergence in plant traits and trait plasticity after invasion has been proposed as mechanisms favouring invasion success. Current hypotheses predict a rapid evolution in response to changes in the abiotic conditions in the area of introduction or to differences in the herbivore consumption pressure caused by a decrease in the enemies associated with the area of origin [e.g. evolution of increased competitive ability (EICA) hypothesis]. The importance of these factors in determining plant geographical divergence has not been yet simultaneously evaluated. Senecio pterophorus (Asteraceae) is a perennial shrub native to eastern South Africa and a recent invader in western South Africa (since ~100 years ago), Australia (>70-100 years) and Europe (>30 years). These areas differ in their summer drought stress [measured as the ratio of summer precipitation to potential evapotranspiration (P/PET)] and their interactions with herbivores. We performed a common garden experiment with S. pterophorus sampled throughout its entire known distributional area to determine (i) whether native and non-native populations diverge in their traits, as well as the plasticity of these traits in response to water availability and (ii) whether climate and herbivory play a role in the genetic differentiation across regions. Plants from the non-native regions were smaller and had a lower reproductive output than plants from the indigenous area. No geographical differences in phenotypic plasticity were found in response to water availability. Herbivory was not related to the plant geographical divergence. In contrast, our results are consistent with the role of climate as a driver for postinvasive evolution, as suggested by adaptation of plants to a drought cline in the native range, the analogous change in plant traits in independently invaded regions and the convergence of vegetative traits between non-native plants and native plants under similar drought conditions. Native and non-native populations of S. pterophorus differed in plant traits, but not in trait plasticity, in response to their local climatic conditions. Our results are contrary to the role of herbivory as a selective factor after invasion and highlight the importance of climate driving rapid evolution of exotic plants. © 2015 The Authors.

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Fodder biomass monitoring in Sahelian rangelands using phenological metrics from FAPAR time series

Diouf A.A., Brandt M., Verger A., El Jarroudi M., Djaby B., Fensholt R., Ndione J.A., Tychon B. (2015) Fodder biomass monitoring in Sahelian rangelands using phenological metrics from FAPAR time series. Remote Sensing. 7: 9122-9148.
Link
Doi: 10.3390/rs70709122

Abstract:

Timely monitoring of plant biomass is critical for the management of forage resources in Sahelian rangelands. The estimation of annual biomass production in the Sahel is based on a simple relationship between satellite annual Normalized Difference Vegetation Index (NDVI) and in situ biomass data. This study proposes a new methodology using multi-linear models between phenological metrics from the SPOT-VEGETATION time series of Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) and in situ biomass. A model with three variables-large seasonal integral (LINTG), length of growing season, and end of season decreasing rate-performed best (MAE = 605 kg·DM/ha; R2 = 0.68) across Sahelian ecosystems in Senegal (data for the period 1999-2013). A model with annual maximum (PEAK) and start date of season showed similar performances (MAE = 625 kg·DM/ha; R2 = 0.64), allowing a timely estimation of forage availability. The subdivision of the study area in ecoregions increased overall accuracy (MAE = 489.21 kg·DM/ha; R2 = 0.77), indicating that a relation between metrics and ecosystem properties exists. LINTG was the main explanatory variable for woody rangelands with high leaf biomass, whereas for areas dominated by herbaceous vegetation, it was the PEAK metric. The proposed approach outperformed the established biomass NDVI-based product (MAE = 818 kg·DM/ha and R2 = 0.51) and should improve the operational monitoring of forage resources in Sahelian rangelands. © 2015 by the authors.

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Localized effects of coarse woody material on soil oribatid communities diminish over 700 years of stand development in black-spruce-feathermoss forests

Doblas-Miranda E., Work T.T. (2015) Localized effects of coarse woody material on soil oribatid communities diminish over 700 years of stand development in black-spruce-feathermoss forests. Forests. 6: 914-928.
Link
Doi: 10.3390/f6040914

Abstract:

In the black-spruce clay-belt region of Western Québec, soil nutrients are limited due to paludification. Under paludified conditions, nutrient subsidies from decomposing surface coarse woody material (CWM) may be important particularly during the later stages of ecosystem development when deadwood from senescent trees has accumulated. For soil organisms, CWM can alter microclimatic conditions and resource availability. We compared abundance and species richness of oribatid mites below or adjacent to CWM across a chronosequence which spans ca. 700 years of stand development. We hypothesized that oribatid abundance and richness would be greater under the logs, particularly in later stages of forest development when logs may act as localized sources of carbon and nutrients in the paludified substrate. However, oribatid density was lower directly under CWM than adjacent to CWM but these differences were attenuated with time. We suggest that oribatids may be affected by soil compaction and also that such microarthropods are most likely feeding on recently fallen leaf litter, which may be rendered inaccessible by the presence of overlying CWM. This may also explain the progressive decline in oribatid density and diversity with time, which are presumably caused by decreases in litter availability due to self-thinning and Sphagnum growth. This is also supported by changes of different oribatid trophic groups, as litter feeders maintain different numbers relative to CWM with time while more generalist fungi feeders only show differences related to position in the beginning of the succession. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

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Brown and brook trout populations in the Tatra Mountain lakes (Slovakia, Poland) and contamination by long-range transported pollutants

Dockalova K., Holubcova J., Bacardit M., Bartrons M., Camarero L., Gallego E., Grimalt J.O., Hardekopf D., Horicka Z., Rosseland B.O., Tatosova J., Stuchlik E. (2015) Brown and brook trout populations in the Tatra Mountain lakes (Slovakia, Poland) and contamination by long-range transported pollutants. Biologia (Poland). 70: 516-529.
Link
Doi: 10.1515/biolog-2015-0052

Abstract:

Fish living in the extreme conditions of the Tatra Mountain lakes were evaluated from a biological point of view as well as an important biomarker of long-range transported pollutants. In Velké Hincovo pleso and in Morskie Oko, specimens of brown trout (Salmo trutta) of extraordinarily advanced age were found (ages of 18+ and 17+ years, respectively). The capture of a 17+ year-old brown trout in Morskie Oko (2400 g, 540 mm) indicated the presence of the so-called ferox life strategy. The growth of brook trout (Salvelinus fontinalis) was faster than the growth of brown trout in the younger year classes, and while the growth of brook trout stopped after the age of 5+, the growth of brown trout continued. Concentrations of long-range transported pollutants (HCHs, HCB, DDTs, PCBs, PBDEs, and trace metals) in the Tatra Mountain fish were mostly associated with fish age, body weight and length, type of fish tissue, and lake altitude. Persistent organic pollutants (POPs) in fish muscle were dominated by PCBs 138, 153, 180, and p,p'-DDE. Conversely, PBDEs concentrations ranged at substantially lower levels compared to other POPs. Altitude correlated significantly with concentrations of a-HCH, HCB, p,p'-DDT, p,p'-DDE, and with PCBs 28 and 52. The highest contents of trace metals were found in kidney and liver samples, with higher concentrations in Velké Hincovo pleso than in Morskie Oko. The overall highest trace metal concentration levels were found for Fe, Cu, and Zn. In comparison with other European mountain lakes, the Tatra Mountain lakes are among the more contaminated. © 2015 Institute of Zoology, Slovak Academy of Sciences.

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Ecotoxicological characterization of biochars: Role of feedstock and pyrolysis temperature

Domene X., Enders A., Hanley K., Lehmann J. (2015) Ecotoxicological characterization of biochars: Role of feedstock and pyrolysis temperature. Science of the Total Environment. 512-513: 552-561.
Link
Doi: 10.1016/j.scitotenv.2014.12.035

Abstract:

Seven contrasting feedstocks were subjected to slow pyrolysis at low (300 or 350°C) and high temperature (550 or 600°C), and both biochars and the corresponding feedstocks tested for short-term ecotoxicity using basal soil respiration and collembolan reproduction tests. After a 28-d incubation, soil basal respiration was not inhibited but stimulated by additions of feedstocks and biochars. However, variation in soil respiration was dependent on both feedstock and pyrolysis temperature. In the last case, respiration decreased with pyrolysis temperature (r=-0.78; p<0.0001, n=21) and increased with a higher volatile matter content (r=0.51; p<0.017), these two variables being correlated (r=-0.86, p<0.0001). Collembolan reproduction was generally unaffected by any of the additions, but when inhibited, it was mostly influenced by feedstock, and generally without any influence of charring itself and pyrolysis temperature. Strong inhibition was only observed in uncharred food waste and resulting biochars. Inhibition effects were probably linked to high soluble Na and NH4 concentrations when both feedstocks and biochars were considered, but mostly to soluble Na when only biochars were taken into account. The general lack of toxicity of the set of slow pyrolysis biochars in this study at typical field application rates (≤20Mgha-1) suggests a low short-term toxicity risk. At higher application rates (20-540Mgha-1), some biochars affected collembolan reproduction to some extent, but only strongly in the food waste biochars. Such negative impacts were not anticipated by the criteria set in currently available biochar quality standards, pointing out the need to consider ecotoxicological criteria either explicitly or implicitly in biochar characterization schemes or in management recommendations. © 2014 Elsevier B.V.

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Short-term mesofauna responses to soil additions of corn stover biochar and the role of microbial biomass

Domene X., Hanley K., Enders A., Lehmann J. (2015) Short-term mesofauna responses to soil additions of corn stover biochar and the role of microbial biomass. Applied Soil Ecology. 89: 10-17.
Link
Doi: 10.1016/j.apsoil.2014.12.005

Abstract:

Biochar additions have been suggested to influence soil microbial communities that, through a cascade effect, may also impact soil fauna. In turn, any direct biochar effects on fauna can influence microbial communities through grazing, physical fragmentation of organic debris (and biochar) and modifying soil structure. If biochar creates a favorable environment for soil microorganisms, it is also plausible for fauna to be attracted to such microbially enriched habitats. However, how soil fauna respond to biochar addition to soil and what are the main factors that drive their behavior has rarely been experimentally addressed. Therefore, the behavior of two mesofauna species was assessed as a result of corn stover biochar (slow pyrolysis at 600°C) additions to a loamy temperate soil, after preincubation for 2, 17, 31 and 61d, and related to variations in microbial biomass and activity. Microbial biomass increased by 5-56% and activity by 6-156% with increasing biochar rates for the different preincubation times. Over the incubation time, microbial biomass did not change or increased at most 15% with the different biochar rates, while in turn microbial activity decreased steadily (around 70-80% at day 61). Enchytraeids generally did not show avoidance or preference to biochar when provided with an alternative unamended soil, while collembolans often showed avoidance responses. However, collembolan avoidance to biochar decreased or disappeared in biochar mixtures with higher microbial biomass and soluble NH4-N content, agreeing with the plausible role of microorganisms to potentially attract soil fauna after biochar applications. Avoidance response was mainly explained by environmental preferences of the test species and not by any toxic effect of the biochar in this study. However, avoidance after the application of biochar may still need to be considered due to the potential negative impacts of individuals' migration on soil ecosystem functioning. © 2014 Elsevier B.V.

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Predictive modelling of fire occurrences from different fire spread patterns in Mediterranean landscapes

Duane A., Pique M., Castellnou M., Brotons L. (2015) Predictive modelling of fire occurrences from different fire spread patterns in Mediterranean landscapes. International Journal of Wildland Fire. 24: 407-418.
Link
Doi: 10.1071/WF14040

Abstract:

Fire regimes are shifting worldwide because of global changes. The relative contribution of climate, topography and vegetation greatly determines spatial and temporal variations in fire regimes, but the interplay of these factors is not yet well understood. We introduce here a novel classification of fires according to dominant fire spread pattern, an approach considered in operational firefighting, to help understand regional-scale spatial variability in fire regimes. Here, we studied whether climate, topography and fuel variables allowed the prediction of occurrences from different fire spread patterns in Catalonia, NE Spain. We used a correlative modelling approach based on maximum entropy methods, and examined, through variation partitioning, the relative contribution of different factors on determining their occurrence. Our results accurately predicted the occurrence of different fire spread patterns, and the results were consistent when temporal validation was conducted. Although forest fuel factors made a higher contribution to the occurrence of convective fires, wind-driven fires were strongly related to topographic and climate factors. These findings may have a strong impact on investigations into how fire regimes may be projected into the future under forecast global change as they suggest that future environmental changes may affect different fire spread patterns in an idiosyncratic manner. © IAWF 2015.

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