Driftwood

About: Driftwood is a research topic. Over the lifetime, 257 publications have been published within this topic receiving 4827 citations.

Island‐dominated landscapes of large floodplain rivers, a European perspective

Abstract: 1. The landscapes of large floodplain rivers are characterised by heterogeneous environments related to the interplay of flood flows, sediment transport and vegetation dynamics. 2. The large rivers of Europe, and probably most rivers throughout the forest biomes, were characterised by islands but over the period of major human interference, many have become dominated by incision and narrowing so that they are now characterised by single-thread and relatively simple channel forms. 3. Vegetation plays an active role in developing heterogeneous channel forms through (a) biotic processes such as seed dispersal, vegetative regeneration and succession and (b) abiotic effects such as increasing flow resistance inducing sedimentation, and decreasing bank erodibility. 4. In particular, accumulations of living driftwood (cf. dead driftwood accumulations and dispersed seedlings) accelerate sedimentation and island development. 5. River reaches with vegetated islands have a high habitat diversity. 6. The natural influences of flood disturbance, wood accumulation, vegetation growth, island development and tree die-off, cause island-dominated reaches to undergo cycles of island growth and decay that are related to cycles of aquatic habitat diversification and simplification.

Effects of deposited wood on biocomplexity of river corridors

Abstract: Under natural conditions, most rivers are bordered by riparian woodland. Many studies have highlighted the ecological importance of these wooded zones, but the impact of riparian woodland dynamics on the complexity of the active tract (the area of bare sediment adjacent to the river) has been overlooked. This paper highlights the impact of downed trees and sprouting driftwood on the development of islands and associated ponds within the active tract of large rivers and the effects of these features on the abundance and diversity of plants and animals, and points to the benefits of riparian woodland for channel restoration.

Trees as riparian engineers: the Tagliamento river, Italy

Abstract: Pristine river corridors were characterized by island and floodplain development driven by the inter-play of flows, sediments and woody vegetation. Here we explore these relationships within topographically controlled settings within the upper, middle and lower reaches of a large, semi-natural alpine to mediterranean river. These reaches have expanding or contracting valley floors within which we show that there are more or less predictable patterns of stream power and rates of vegetation growth, reflecting water availability during dry periods and also the availability of sand and finer sediment. We relate these to the pattern of island distribution that is repeated within the three reaches and is indicative of the engineering role of riparian trees. Islands are shown to develop within thresholds defined by stream power, rates of woody vegetation growth and rates of sedimentation, and to develop most quickly where riparian species include those capable of sprouting from driftwood.

From the Forest to the Sea: The Ecology of Wood in Streams, Rivers, Estuaries and Oceans

Abstract: From the Forest to the Sea: The Ecology of Wood in Streams, Rivers, Estuaries and Oceans is a fascinating new scientific work that discusses the role wood plays in very complex and diverse aquatic ecosystems. Until now almost nothing has been published on this little understood topic. 1. Wood in streams and rivers is a source of food energy for invertebrate organisms; habitat for vertebrate organisms, such as fish; and a structural component that shapes, diversifies, and stabilizes channels while helping to dissipate the water's energy before it can scour channels.2. Wood in estuaries is a major source of food and habitat for obligatory, wood boring, marine invertebrates that in their feeding, break it down and pass usable carbon into the water's current where it enters the detrital based marine food web.3. Wood along the coastline stabilizes sand spits, beaches, and dune complexes, as well as battering rocky shores where it creates new habitats for intertidal organisms and provides small splinters of wood to the coastal food chain.4. Driftwood floating in the open ocean attracts a variety of marine invertebrates and fishes, forming a floating surface community that help organisms colonize new areas. Large fishes, such as tuna, not only feed on smaller fishes attracted to the wood but also drift with it because its movement is controlled by wind and current; thus tuna find the best feeding areas-current interfaces rich in food species. 5. A common textbook perception on marine biology is that, while communities of bacteria can use sulfur compounds as energy and animals can and do live around deep-sea hydrothermal vents through which hot water issues in the ocean's floor, the rest of the oceans bottom is almost devoid of life. But as driftwood becomes waterlogged and sinks, it represents terrestrially-fixed carbon in the energy poor deep-sea where at least three species of wood-borers convert it into a readily available source of detritus that in turn supports the development of complex communities of bottom-dwelling organisms.6. The loss of wood to aquatic ecosystems means destabilization of streams, estuaries, dunes and beaches as well as food chains in the oceans of the world. Sooner or later it may mean the loss of jobs and unique cultural ways of life such as the commercial fishing of certain species.

Chronology of the last recession of the Greenland Ice Sheet

Abstract: A new deglaciation chronology for the ice-free parts of Greenland, the continental shelf and eastern Ellesmere Island (Canada) is proposed. The chronology is based on a new compilation of all published radiocarbon dates from Greenland, and includes crucial new material from southern, northeastern and northwestern Greenland. Although each date provides only a minimum age for the local deglaciation, some of the dates come from species that indicate ice-proximal glaciomarine conditions, and thus may be connected with the actual ice recession. In addition to shell dates, dates from marine algae, lake sediments, peat, terrestrial plants and driftwood also are included. Only offshore and in the far south have secure late-glacial sediments been found. Other previous reports of late-glacial sediments (older than 11.5 cal. kyr BP) from onshore parts of Greenland need to be confirmed. Most of the present ice-free parts of Greenland and Nares Strait between Greenland and Ellesmere Island were not deglaciated until the early Holocene. Copyright (C) 2002 John Wiley Sons, Ltd. (Less)