Journal of Applied Ecology

Journal: Journal of Applied Ecology

Abbreviation

J. Appl. Ecol.

Publisher

Wiley-Blackwell

ISSN

0021-8901
1365-2664

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Publications 1 - 10 of 41

Grassland extensification enhances nest densities of ground-nesting wild bees
Albrecht, Matthias; Bossart, Stefanie; Tschanz, Philippe; et al. (2023)
Journal of Applied Ecology
1. Ground-nesting wild bees provide essential pollination services in agroecosystems, but they are jeopardized by intensive agricultural management. To mitigate such negative impacts, agri-environment schemes have been implemented. While the success of enhancing floral food resources is relatively well studied, the role of agri-environmental schemes in providing suitable nesting habitat remains underexplored. 2. We studied the effectiveness of meadow extensification according to the Swiss agri-environment scheme in promoting nesting of ground-nesting bees. Using a paired design, we quantified their nests during four rounds (March-June) in pairs of nine randomly selected extensively (i.e. no fertilizer input, postponed first mowing) and nine intensively managed meadows with similar soil properties, slope, exposure and landscape context. Nest numbers and vegetation characteristics were surveyed in areas of 250 m². Vegetation properties were also assessed in 0.5 x 0.5 m plots around nest locations and randomly selected locations without nests within each meadow to assess their role as drivers of nesting incidence (nest presence/absence) at this plot scale. 3. We found substantially higher nest numbers of ground-nesting bees in extensively (mean +/- SE per sampling round = 46.8 +/- 14.2) compared to intensively managed meadows (0.8 +/- 0.3; no nests in three of nine intensively managed meadows). Extensively managed meadows harboured nests of several dominant crop pollinator species, including aggregations of, for example, Lasioglossum malachurum contributing to high nest densities in some of them. Number of nests was negatively related to grass cover and vegetation height, which were lower in extensively compared to intensively managed meadows. Plot-level nesting incidence increased with bare ground and moss cover, and decreased with grass cover. 4. Synthesis and applications. Our study shows that extensively managed meadows are better nesting habitats for ground-nesting bees than intensively managed meadows, if reduced management intensity is associated with altered vegetation characteristics such as reduced grass cover and vegetation height, and small-scale availability of bare ground, driving these effects. This highlights that maintaining and promoting extensive management of meadows can promote ground-nesting wild bees, including dominant crop pollinators, not only by enhancing floral resources but also by improving nesting opportunities in agroecosystems.
Genetic mixing from enhancement stocking in commercially exploited vendace populations
Mehner, T.; Pohlmann, K.; Elkin, C.; et al. (2009)
Journal of Applied Ecology
Towards smarter harvesting from natural palm populations by sparing the individuals that contribute most to population growth or productivity
Jansen, Merel; Anten, Niels P.R.; Bongers, Frans; et al. (2018)
Journal of Applied Ecology
1. Natural populations deliver a wide range of products that provide income for millions of people and need to be exploited sustainably. Large heterogeneity in individual performance within these exploited populations has the potential to improve population recovery after exploitation and thus help sustain yields over time. 2. We explored the potential of using individual heterogeneity to design smarter harvest schemes, by sparing individuals that contribute most to future productivity and population growth, using the understorey palm Chamaedorea elegans as a model system. Leaves of this palm are an important non‐timber forest product and long‐term inter‐individual growth variability can be evaluated from internode lengths. 3. We studied a population of 830 individuals, half of which was subjected to a 67% defoliation treatment for 3 years. We measured effects of defoliation on vital rates and leaf size—a trait that determines marketability. We constructed integral projection models in which vital rates depended on stem length, past growth rate and defoliation and evaluated transient population dynamics to quantify population development and leaf yield. We then simulated scenarios in which we spared individuals that were either most important for population growth or had leaves smaller than marketable size. 4. Individuals varying in size or past growth rate responded similar to leaf harvesting in terms of growth and reproduction. By contrast, a reduction in survival chance was smaller in large individuals than in small ones. Simulations showed that harvest‐induced population decline was greatly reduced when sparing individuals from size and past growth classes that contributed most to population growth. Under this scenario, cumulative leaf harvest over 20 years was somewhat reduced, but long‐term leaf production was sustained. A threefold increase in leaf yield was generated when individuals with small leaves were spared. 5. Synthesis and applications. This study demonstrates the potential to create smarter systems of palm leaf harvest by accounting for individual heterogeneity within exploited populations. Sparing individuals that contribute most to population growth ensured sustained leaf production over time. The concepts and methods presented here are generally applicable to exploited plant and animal species which exhibit considerable individual heterogeneity.
Population genetics suggests effectiveness of habitat connectivity measures for the European tree frog in Switzerland
Angelone, Sonia; Holderegger, Rolf (2009)
Journal of Applied Ecology
Extreme climate events counteract the effects of climate and land-use changes in Alpine tree lines
Barros, Ceres; Guéguen, Maya; Douzet, Rolland; et al. (2017)
Journal of Applied Ecology
Synergism between production and soil health through crop diversification, organic amendments and crop protection in wheat-based systems
Walder, Florian; Büchi, Lucie; Wagg, Cameron; et al. (2023)
Journal of Applied Ecology
1. One of the critical challenges in agriculture is enhancing yield without compromising its foundation, a healthy environment and, particularly, soils. Hence, there is an urgent need to identify management practices that simultaneously support soil health and production and help achieve environmentally sound production systems. 2. To investigate how management influences production and soil health under realistic agronomic conditions, we conducted an on-farm study involving 60 wheat fields managed conventionally, under no-till or organically. We assessed 68 variables defining management, production and soil health properties. We examined how management systems and individual practices describing crop diversification, fertiliser inputs, agrochemical use and soil disturbance influenced production—quantity and quality—and soil health focusing on aspects ranging from soil organic matter over soil structure to microbial abundance and diversity. 3. Our on-farm comparison showed marked differences between soil health and production in the current system: organic management resulted in the best overall soil health (+47%) but the most significant yield gap (−34%) compared to conventional management. No-till systems were generally intermediate, exhibiting a smaller yield gap (−17%) and only a marginally improved level of soil health (+5%) compared to conventional management. Yet, the overlap between management systems in production and soil health properties was considerably large. 4. Our results further highlight the importance of soil health for productivity by revealing positive associations between crop yield and soil health properties, particularly under conventional management, whereas factors such as weed pressure were more dominant in organic systems. 5. None of the three systems showed advantages in supporting production-soil health-based multifunctionality. In contrast, a cross-system analysis suggests that multifunctional agroecosystems could be achieved through a combination of crop diversification and organic amendments with effective crop protection. 6. Synthesis and applications: Our on-farm study implies that current trade-offs in managing production and soil health could be overcome through more balanced systems incorporating conventional and alternative approaches. Such multifunctionality supporting systems could unlock synergies between vital ecosystem services and help achieve productive yet environmentally sound agriculture supported by healthy soils.
Manipulation of light spectral quality disrupts host location and attachment by parasitic plants in the genus Cuscuta
Johnson, Beth I.; De Moraes, Consuelo M.; Mescher, Mark C. (2016)
Journal of Applied Ecology
Among stand heterogeneity is key for biodiversity in managed beech forests but does not question the value of unmanaged forests: Response to Bruun and Heilmann-Clausen (2021)
Schall, Peter; Heinrichs, Steffi; Ammer, Christian; et al. (2021)
Journal of Applied Ecology
Schall et al. (2020) assessed how a combination of different forest management systems in managed forest landscapes dominated by European beech may affect the biodiversity (alpha, beta and gamma) of 14 taxonomic groups. Current forest policy and nature conservation often demand for combining uneven-aged managed and unmanaged, set-aside for nature conservation, beech forests in order to promote biodiversity. In contrast to this, Schall et al. (2020) found even-aged shelterwood forests, represented by different developmental phases, to support highest regional (gamma) diversity. By pointing out that unmanaged forests included in our study are not old-growth forests, Bruun and Heilmann-Clausen (2021) challenge our conclusion as not providing sound scientific advice to societies. It is true that the studied unmanaged forests are not representing old-growth forests as defined in the literature. However, we demonstrate the representativeness of our unmanaged forests for current beech forest landscapes of Central Europe, where managed forests were more or less recently set-aside in order to develop old-growth structures. We also show that the managed and recently unmanaged forests in our study already differ distinctively in their forest structures. We use this response to stress the role of forest reserves for promoting certain species groups, and to emphasise their importance as valuable research sites today and in the future. Synthesis and applications. We see two main conclusions from our study. First, unmanaged forests still matter. We agree with Bruun and Heilmann-Clausen (2021) on the general importance of unmanaged, old-growth or long-untouched forests, and we do not question the importance of set-aside forests for biodiversity conservation. However, a complete complementarity to managed systems may only reveal after many decades of natural development. Second, safeguarding biodiversity in largely managed forest landscapes should focus on providing a landscape matrix of different developmental phases with varying environmental conditions rather than on maximising the vertical structure within stands. Such landscapes can partly compensate for structures that are still missing in vital, dense and closed forests recently set-aside or for unsuitable phases that may occur due to a cyclic synchronisation of forest structures in unmanaged forests.
Nesting sites of giant honeybees modulated by landscape patterns
Pavageau, Charlotte; Gaucherel, Cédric; Garcia, Claude; et al. (2018)
Journal of Applied Ecology
Predation risk shaped by habitat and landscape complexity in urban environments
Frey, David; Vega, Kevin; Zellweger, Florian; et al. (2018)
Journal of Applied Ecology

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