Search results for "11"

Ecological mechanisms can modify radiation effects in a key forest mammal of Chernobyl

2019

International audience; Nuclear accidents underpin the need to quantify the ecological mechanisms which determine injury to ecosystems from chronic low-dose radiation. Here, we tested the hypothesis that ecological mechanisms interact with ionizing radiation to affect natural populations in unexpected ways. We used large-scale replicated experiments and food manipulations in wild populations of the rodent, Myodes glareolus, inhabiting the region near the site of the Chernobyl disaster of 1986. We show linear decreases in breeding success with increasing ambient radiation levels with no evidence of any threshold below which effects are not seen. Food supplementation of experimental populatio…

A multisite-cooperative research programme on risk assessment of transgenic crops

1999

Genetically modified plants are now being commercialised in several countries as regulatory authorities consider that the balance of risk versus benefit is beneficial. However, numerous questions remain unanswered, especially the impact of these plants when used over large areas and under a range of variable environmental conditions. Some issues need to be re-evaluated [1, 2]. Risk/safety analysis, as well as prospects of transgenic crops depend on the scale which is to be considered. Extrapolation of methods, and laboratory and greenhouse results, to large-scale farmers’ fields, may provide useful preliminary data, but is not a sound approach to the study of the consequences of the commerc…

Limits and targets for a regional sustainability assessment: an interdisciplinary exploration of the threshold concept

2008

Part 5. Regional and local evaluation-18 ; International audience; Some encompassing terminology is required in order to accommodate different conceptual approaches in the three pillars of sustainability. So, this chapter provides a literature review exploring the threshold concept. In environmental research – especially in ecology – thresholds are often associated with limits which have certain system-inherent processes. In social and economic disciplines, if the notion of limit or critical limit is present, the concept of targets is often more appropriate which are linked to political objectives and social acceptability. The concept of threshold is accommodated within the general framewor…

Microbial communities as ecological indicators of ecosystem recovery following chemical pollution

2017

International audience; ‘Ecosystem recovery’ is a concept that emerged from the need to preserve our environment against increasing contamination from human activity. However, ecological indicators of ecosystem recovery remain scarce, and it is still difficult to assess recovery of ecological processes at relevant spatial and temporal scales. Microbial communities hold key relevance as indicators of ecosystem recovery as they are ubiquitous among diverse ecosystems, respond rapidly to environmental changes, and support many ecosystem functions and services through taxonomic and functional biodiversity. This chapter summarizes the state-of-the-art in knowledge on the processes driving the st…

An Insight in the Reproductive Biology of Therophilus javanus (Hymenoptera, Braconidae, and Agathidinae), a Potential Biological Control Agent agains…

2017

Therophilus javanus is a koinobiont, solitary larval endoparasitoid currently being considered as a biological control agent against the pod borer Maruca vitrata, a devastating cowpea pest causing 20–80% crop losses in West Africa. We investigated ovary morphology and anatomy, oogenesis, potential fecundity, and egg load in T. javanus, as well as the effect of factors such as age of the female and parasitoid/host size at oviposition on egg load. The number of ovarioles was found to be variable and significantly influenced by the age/size of the M. vitrata caterpillar when parasitized. Egg load also was strongly influenced by both the instar of M. vitrata caterpillar at the moment of parasit…

Prospects of herbivore egg-killing plant defenses for sustainable crop protection

2016

Abstract Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest‐resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg‐killing. Insect eggs can trigger (1) direct defenses, mostly i…

Assessing the capacity of different urban forms to preserve the connectivity of ecological habitats

2011

International audience; This paper addresses the relationship between anthropogenic forest habitat fragmentation and the form of urban patterns. Using a two-step methodology we first generate 40 theoretical residential development scenarios following a repeatable procedure; the simulated urban forms are either moderately compact or fractal. Then, we compare the scenarios according to the functional connectivity of the remaining forest habitat using a graph-based approach. The methodology is applied to the urban region of Besançon (France), where forest surfaces are considered as a generic habitat for several animal species. Results obtained show that fractal scenarios of residential develop…

Priorities for research in soil ecology

2017

The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decades ago, and we have gained important insights into the functioning of soils, there still are fundamental aspects that need to be better understood to ensure that the ecosystem services that soils provide are not lost and that soils can be used in a sustainable way. In this perspectives paper, we highlight some of the major knowledge gaps that shoul…

Estimating the abundance of burrow-nesting species through the statistical analysis of combined playback and visual surveys

2016

Towards sustainable and multifunctional agriculture in farmland landscapes: Lessons from the integrative approach of a French LTSER platform

2018

International audience; Agriculture is currently facing unprecedented challenges: ensuring food, fiber and energy production in the face of global change, maintaining the economic performance of farmers and preserving natural resources such as biodiversity and associated key ecosystem services for sustainable agriculture. Addressing these challenges requires innovative landscape scale farming systems that account for changing economic and environmental targets. These novel agricultural systems need to be recognized, accepted and promoted by all stakeholders, including local residents, and supported by public policies. Agroecosystems should be considered as socio-ecological systems and alter…