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The use of large wood in stream restoration: experiences from 50 projects in Germany and Austria
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1. Wood is increasingly used in restoration projects to improve the hydromorphological and ecological status of streams and rivers. However, despite their growing importance, only a few of these projects are described in the open literature. To aid practitioners, we conducted a postal mail survey to summarize the experiences gained in central Europe and compile data on 50 projects.
2. Our results indicated the potential for improvement from an ecological point of view, as the number and total wood volume, and the median volume of single wood structures placed in the streams per project, were low compared with the potential natural state. Moreover, many wood structures were placed nearly parallel to the water flow, reducing their beneficial effect on stream hydraulics and morphology.
3. Restoration success has been monitored in only 58% of the projects. General con- clusions drawn include the following. (i) The potential effects of wood placement must be evaluated within a watershed and reach-scale context. (ii) Wood measures are most successful if they mimic natural wood. (iii) Effects of wood structures on stream morphology are strongly dependent on conditions such as stream size and hydrology. (iv) Wood placement has positive effects on several fish species. (v) Most projects revealed a rapid improvement of the hydromorphological status.
4. Most of the wood structures have been fixed, called ‘hard engineering’. However, soft engineering methods (use of non-fixed wood structures) are known to result in more natural channel features for individual stream types, sizes and sites, and are significantly more cost-effective.
5. Synthesis and applications. Large wood has been used successfully in several projects in central Europe, predominantly to increase the general structural complexity using fixed wood structures. Our results recommend the use of less costly soft engineering techniques (non-fixed wood structures), higher amounts of wood, larger wood struc- tures and improved monitoring programmes for future restoration projects comparable with those in this study. We recommend the use of ‘passive restoration’ methods (restor- ing the process of wood recruitment on large scales) rather than ‘active restoration’ (placement of wood structures on a reach scale), as passive restoration avoids the risk of non-natural amounts or diversity of wood loading developing within streams. Local, active placement of wood structures must be considered as an interim measure until passive restoration methods have increased recruitment sufficiently.
Key-words: alpine streams, lowland streams, monitoring, mountain streams, passive restoration, restoration success, soft-engineering, woody debris
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The velocity of climate change
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The ranges of plants and animals are moving in response to recent changes in climate1. As temperatures rise, ecosystems with ‘nowhere to go’, such as mountains, are considered to be more threatened2,3. However, species survival may depend as much on keeping pace with moving climates as the climate’s ultimate per- sistence4,5. Here we present a new index of the velocity of temper- ature change (km yr21), derived from spatial gradients (6C km21) and multimodel ensemble forecasts of rates of temperature increase (6C yr21) in the twenty-first century. This index represents the instantaneous local velocity along Earth’s surface needed to maintain constant temperatures, and has a global mean of 0.42 km yr21 (A1B emission scenario). Owing to topographic effects, the velocity of temperature change is lowest in mountainous biomes such as tropical and subtropical coniferous forests (0.08kmyr21), temperate coniferous forest, and montane grass- lands. Velocities are highest in flooded grasslands (1.26 km yr21), mangroves and deserts. High velocities suggest that the climates of only 8% of global protected areas have residence times exceeding 100 years. Small protected areas exacerbate the problem in Mediterranean-type and temperate coniferous forest biomes. Large protected areas may mitigate the problem in desert biomes. These results indicate management strategies for minimizing biodiversity loss from climate change. Montane landscapes may effectively shelter many species into the next century. Elsewhere, reduced emissions, a much expanded network of protected areas6, or efforts to increase species movement may be necessary7.
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The Wheel of Life Food, Climate, Human Rights, and the Economy
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The links between climate change and industrial agriculture create a nexus of crises—food
insecurity, natural resource depletion and degradation, as well as human
rights violations and inequities.
While it is widely recognized that greenhouse gas (GHG) emissions due
to human activity are detrimental to the natural environment, it can be difficult to
untangle the cascading effects on other sectors. To unravel some of the effects, this
paper focuses on three interrelated issues:
1) What are the critical links between climate change and agriculture?
2) How is the nexus of agriculture and climate change affecting human societies
particularly regarding food and water, livelihoods, migration, gender
equality, and other basic survival and human rights?
3) What is the interplay between economic and finance systems, on the one
hand, and food security, climate change, and fundamental human rights, on
the other?
In the process of drawing connections among these issues, the report will identify
the commonality of drivers, or “push” factors, that lead to adverse impacts.
A central theme throughout this report is that policies and practices must
begin with the ecological imperative in order to ensure authentic security and stability
on all fronts including food, water, livelihoods and jobs, climate, energy, and
economic. In turn this engenders equity, social justice, and diverse cultures. This
imperative, or ethos of nature, is a foundation that serves as a steady guide when
reviewing mitigation and adaptation solutions to climate change.
Infused within this theme is the sobering recognition that current consumption
and production patterns are at odds with goals of reducing GHGs and attaining
global food security. For instance, consumption and production levels, based on the
global average, are 25 percent higher than the earth’s ecological capacity.1
As societies
address the myriad ecological and social issues at the axis of global warming,
a central task will be to re-align consumption and production trends in a manner
that can fulfill economic and development requirements. This will require a major
shift away from present economic growth paradigms based on massive resource
extraction and toward creating prosperous and vital societies and economies that
preserve the planet’s environmental capacity
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Theler 1987.pdf
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TRB Library
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THA-TUD
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Theler 1991.pdf
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THA-TUD
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Thermal legacies: transgenerational effects of temperature on growth in a vertebrate
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Transgenerational plasticity (TGP), a generalisation of more widely studied maternal effects, occurs whenever environmental cues experienced by either parent prior to fertilisation results in a modification of offspring reaction norms. Such effects have been observed in many traits across many species. Despite enormous potential importance—particularly in an era of rapid climate change—TGP in thermal growth physiology has never been demonstrated for vertebrates. We provide the first evidence for thermal TGP in a vertebrate: given sufficient time, sheepshead minnows adaptively program their offspring for maximal growth at the present temperature. The change in growth over a single generation (c. 30%) exceeds the single-generation rate of adaptive evolution by an order of magnitude. If widespread, transgenerational effects on thermal performance may have important implications on physiology, ecology and contemporary evolution, and may significantly alter the extinction risk posed by changing climate.
Keywords
Cyprinodon variegatus, ecological epigenetics, maternal effects, sheepshead minnow.
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They Know How to Prevent Megafires. Why Won’t Anybody Listen?
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This is a story about frustration, about watching the West burn when you fully understand why it’s burning — and understand why it did not need to be this bad.
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Thinking Big: Linking Rivers to Landscapes
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Exploring relationships between
landscape characteristics and rivers is
an emerging field of study, bolstered
by the proliferation of satellite data,
advances in statistical analysis,
and increased emphasis on largescale
monitoring. Climate patterns
and landscape features such as road
networks, underlying geology, and
human developments determine the
characteristics of the rivers flowing
through them. A multiagency team of
scientists developed novel modeling
methods to link these landscape features
to instream habitat and to abundance of
coho salmon in Oregon coastal streams.
This is the first comprehensive analysis
of landscape-scale data collected as
part of the state’s Oregon Plan for
Salmon and Watersheds.
The research team found that watershed
characteristics and human activities
far from the river’s edge influence
the distribution and habitats of coho
salmon. Although large-scale landscape
characteristics can predict stream
reaches that might support greater
numbers of coho salmon, smaller
scale features and random chance
also play a role in whether coho
spawn in a particular stream and in a
particular year. The team developed
new models that successfully predicted
the distribution of instream habitat
features. Volume of instream wood
and pool frequency were the features
most influenced by human activities.
Studying these relationships can help
guide large-scale monitoring and
management of aquatic resources.
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Thinking Long Term
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Thousand-year records of animal population patterns and climate yield insights into the impacts of environmental change.
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Third Thursday Web Forum: Updates and applications of USGS Gap Analysis Project data
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“Updates and applications of USGS Gap Analysis Project data” with Nathan Tarr, Research Associate at the Biodiversity and Spatial Information Center within the North Carolina Cooperative Fish and Wildlife Research Unit
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