Search results for "Macro"

Structure and vulnerability of the multi‐interaction network in macrophyte‐dominated lakes

2019

The network approach is crucial to understand how ecosystems are structured and how they will respond to the disturbances (e.g. the current global change). We have recreated the multi‐interaction network of a shallow freshwater lake dominated by submerged macrophytes (Charophytes), a known system very vulnerable to environmental changes, considering both trophic and non‐trophic relationships among its elements. To minimize the environmental variability, we established it in an experimental mesocosm, including three habitats: the pelagic, the habitat around the meadow and the periphytic community living on macrophytes. We aimed to study the structure of this network and the roles of its elem…

Persistence of submerged macrophytes in a drying world: Unravelling the timing and the environmental drivers to produce drought-resistant propagules

2018

Comparing stressor-specific indices and general measures of taxonomic composition for assessing the status of boreal lacustrine macrophyte communities

2013

Abstract Biotic communities are increasingly used to assess and monitor aquatic ecosystems with two fundamentally contrasting approaches: (i) responses sensitive to, and indicative of specific stressors; and (ii) general measures of community change. For assessment of lacustrine macrophyte communities, we compared three trophy-related and one water level fluctuation-related stressor-specific indices (SSIs) with three general measures of taxonomic composition (MTC), using data from 48 reference, 33 eutrophicated and 24 water level regulated boreal lakes. Our hypothesis was that MTCs would yield robust ecological quality estimates across these differing stress-gradients, while the SSIs would …

On the tolerance of charophytes to high-nitrate concentrations

2017

Currently a debate exists about whether the reduced growth of macrophytes with increased nitrogen loading in shallow ecosystems is determined by ecological or physiological factors. To discover whe...

Eight decades of adaptive changes in herring reproductive investment: the joint effect of environment and exploitation

2021

Abstract Reproductive investment is a central trait for population dynamics and productivity. Fishing and environmental variations are major drivers affecting population structure, dynamics, and adaptation of life-history and behavioural traits. However, those factors are often considered independently, and few studies take into account their joint effect. In this study, we investigate the contribution of environment, fishing pressure, and intra-specific competition to variation in the reproductive investment of the Norwegian spring-spawning herring (Clupea harengus), a stock that has been fished for centuries, and monitored for decades. Reproductive investment and post-spawning weight were…

Species specificity of trail pheromones of fungus-growing termites from northern Vietnam

2001

Trail-following pheromones were studied in four fungus-growing termites from northern Vietnam: Macrotermes annandalei, M. barneyi, Odontotermes hainanensis and O. maesodensis. From bioassays, we suggest that trail pheromones of these species are composed of a common or anony-mous signal, as well as species-specific signals. The anonymous signal has been identified by GC-MS as (Z)-dodec-3-en-1-ol for each species from extracts of sternal glands and from solid phase microextraction of the surface of their sternal gland. This compound is secreted in much higher quantities (up to 1.4 ng/worker) than dodecatrienol, another anonymous signal of trail-following in termites. (Z)-dodec-3-en-1-ol is a…

Macrophyte assessment in European lakes: Diverse approaches but convergent views of ‘good’ ecological status

2018

Graphical abstract

Enforced monoandry over generations induces a reduction of female investment into reproduction in a promiscuous bird.

2021

Abstract While uncovering the costs and benefits of polyandry has attracted considerable attention, assessing the net effect of sexual selection on population fitness requires the experimental manipulation of female mating over generations, which is usually only achievable in laboratory populations of arthropods. However, knowing if sexual selection improves or impairs the expression of life‐history traits is key for the management of captive populations of endangered species, which are mostly long‐lived birds and mammals. It might therefore be questionable to extrapolate the results gathered on laboratory populations of insects to infer the net effect of sexual selection on populations of …

Carnivore stable carbon isotope niches reflect predator-prey size relationships in African savannas.

2017

Predator-prey size relationships are among the most important patterns underlying the structure and function of ecological communities. Indeed, these relationships have already been shown to be important for understanding patterns of macroevolution and differential extinction in the terrestrial vertebrate fossil record. Stable isotope analysis (SIA) is a powerful remote approach to examining animal diets and paleodiets. The approach is based on the principle that isotope compositions of consumer tissues reflect those of their prey. In systems where resource isotope compositions are distributed along a body size gradient, SIA could be used to reconstruct predator-prey size relationships. We …

Vitality and growth of the threatened lichen Lobaria pulmonaria (L.) Hoffm. in response to logging and implications for its conservation in mediterra…

2020

Forest logging can be detrimental for non-vascular epiphytes, determining the loss of key components for ecosystem functioning. Legal logging in a Mediterranean mixed oak forest (Tuscany, Central Italy) in 2016 heavily impacted sensitive non-vascular epiphytes, including a large population of the threatened forest lichen Lobaria pulmonaria (L.) Hoffm. This event offered the background for this experiment, where the potential effects of logging in oak forests are simulated by means of L. pulmonaria micro-transplants (thallus fragments &lt