Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
289,761
result(s) for
"Ecology, environment"
Sort by:
The international handbook of political ecology
'The International Handbook of Political Ecology' features chapters by leading scholars from around the world in a unique collection exploring the multi-disciplinary field of political ecology. This landmark volume canvasses key developments, topics, issues, debates and concepts showcasing how political ecologists today address pressing social and environmental concerns.
Book
Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
Journal Article
What the wild sea can be : the future of the world's ocean
No matter where we live, 'we are all ocean people', Helen Scales observes in her bracing yet hopeful exploration of the future of the ocean. Beginning with its fascinating deep history, Scales links past to present to show how prehistoric ocean ecology holds lessons for the ocean of today. In elegant, evocative prose, she takes readers into the realms of animals that epitomize current increasingly challenging conditions, from emperor penguins to sharks and orcas. Yet despite these threats, many hopeful signs remain. Increasing numbers of no-fish zones around the world are restoring once-diminishing populations. Astonishing giant kelp and sea grass forests, rivaling those on land, are being regenerated and expanded, while efforts to reengineer coral reefs for a warmer world are growing.
Book
Elevation alters ecosystem properties across temperate treelines globally
Examination of the ecosystem properties of treeline ecotones in seven temperate regions of the world shows that the reduction in temperature with increasing elevation does not affect tree leaf nutrient concentrations, but does reduce ground-layer community-weighted plant nitrogen levels, leading to a strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all regions.
Ecosystem properties at the treeline
Jordan Mayor
et al
. examine the ecosystem properties of treeline ecotones in mountainous areas of seven temperate regions of the world. They find that the reduction in temperature with increasing elevation does not affect tree leaf nutrient concentrations, but does reduce ground-layer community-weighted plant nitrogen levels. This leads to a strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all of the regions.
Temperature is a primary driver of the distribution of biodiversity as well as of ecosystem boundaries
1
,
2
. Declining temperature with increasing elevation in montane systems has long been recognized as a major factor shaping plant community biodiversity, metabolic processes, and ecosystem dynamics
3
,
4
. Elevational gradients, as thermoclines, also enable prediction of long-term ecological responses to climate warming
5
,
6
,
7
. One of the most striking manifestations of increasing elevation is the abrupt transitions from forest to treeless alpine tundra
8
. However, whether there are globally consistent above- and belowground responses to these transitions remains an open question
4
. To disentangle the direct and indirect effects of temperature on ecosystem properties, here we evaluate replicate treeline ecotones in seven temperate regions of the world. We find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all regions. Further, elevation-driven changes in plant nutrients were associated with changes in soil organic matter content and quality (carbon to nitrogen ratios) and microbial properties. Combined, our identification of direct and indirect temperature controls over plant communities and soil properties in seven contrasting regions suggests that future warming may disrupt the functional properties of montane ecosystems, particularly where plant community reorganization outpaces treeline advance.
Journal Article
Improving irrigation in Asia : sustainable performance of an innovative intervention in Nepal
This text is based on a longitudinal study over two decades on innovative intervention for sustained performance of irrigation systems. It identifies key factors that can help explain the performance of interventions, and explicates lessons for resource management and the management of development assistance.
Book
Prediction of unprecedented biological shifts in the global ocean
Impermanence is an ecological principle1 but there are times when changes occur nonlinearly as abrupt community shifts (ACSs) that transform the ecosystem state and the goods and services it provides2. Here, we present a model based on niche theory3 to explain and predict ACSs at the global scale. We test our model using 14 multi-decadal time series of marine metazoans from zooplankton to fish, spanning all latitudes and the shelf to the open ocean. Predicted and observed fluctuations correspond, with both identifying ACSs at the end of the 1980s4–7 and 1990s5,8. We show that these ACSs coincide with changes in climate that alter local thermal regimes, which in turn interact with the thermal niche of species to trigger long-term and sometimes abrupt shifts at the community level. A large-scale ACS is predicted after 2014—unprecedented in magnitude and extent—coinciding with a strong El Niño event and major shifts in Northern Hemisphere climate. Our results underline the sensitivity of the Arctic Ocean, where unprecedented melting may reorganize biological communities5,9, and suggest an increase in the size and consequences of ACS events in a warming world.Abrupt community shifts, for marine species from zooplankton to fish, are shown to occur with local climate changes in which warming pushes species beyond their thermal niche. This modelling approach suggests future events will be larger and have more broad-reaching impacts.
Journal Article
Handbook of global environmental politics
A handbook of original articles by leading scholars of global environmental politics, this volume maps the latest theoretical and empirical research in this new and growing field.
Book
Global relationships in tree functional traits
Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.
Understanding patterns in woody plant trait relationships and trade-offs is challenging. Here, by applying machine learning and data imputation methods to a global database of georeferenced trait measurements, the authors unravel key relationships in tree functional traits at the global scale.
Journal Article
Estimating groundwater recharge
Provides a critical evaluation of the theory and assumptions that underlie methods for estimating rates of groundwater recharge.
Book
Global evidence of positive biodiversity effects on spatial ecosystem stability in natural grasslands
The effect of biodiversity on primary productivity has been a hot topic in ecology for over 20 years. Biodiversity–productivity relationships in natural ecosystems are highly variable, although positive relationships are most common. Understanding the conditions under which different relationships emerge is still a major challenge. Here, by analyzing HerbDivNet data, a global survey of natural grasslands, we show that biodiversity stabilizes rather than increases plant productivity in natural grasslands at the global scale. Our results suggest that the effect of species richness on productivity shifts from strongly positive in low-productivity communities to strongly negative in high-productivity communities. Thus, plant richness maintains community productivity at intermediate levels. As a result, it stabilizes plant productivity against environmental heterogeneity across space. Unifying biodiversity–productivity and biodiversity–spatial stability relationships at the global scale provides a new perspective on the functioning of natural ecosystems.
Biodiversity–productivity relationships in natural ecosystems are highly variable, although positive relationships are most common. Here, using HerbDivNet data, the authors show that biodiversity stabilizes rather than increases plant productivity in natural grasslands at the global scale.
Journal Article