Similarly, near-shore terrestrial vegetation cover and complexity were typically low where drawdown had increased the distance from the land-water interface to terrestrial vegetation at the normal high water mark. Littoral habitat complexity diminished as drawdown exposed previously littoral habitat features including snags, overhanging vegetation, and aquatic macrophytes. Anthropogenic disturbances and level controls were positively associated with drawdown in some regions, but appeared to dampen natural level fluctuations in others. Lake drawdown magnitudes differed among regions of the U.S., and between natural and human-made lakes. EPA’s National Lakes Assessment summer surveys were evidenced by "bathtub rings" extending 0 to >100m horizontally. Lake level fluctuations in lakes of the U.S. Shoreline zones are hot-spots for both biological diversity and human activity. Structural complexity at the land-water interface of lakes promotes interchange of water, nutrients and energy and provides diverse habitat for aquatic and terrestrial organisms. Lake ecological integrity would be fostered by minimizing anthropogenic drawdown, but where large drawdowns are unavoidable, the authors recommend that management should focus on maintaining structural complexity within the zone of drawdown. Lake-level reductions resulting from increased human use of water possibly exacerbated by climate change can therefore reduce near-shore habitat complexity. They report that littoral habitat complexity was diminished where drawdown had exposed previously inundated littoral habitat features including snags, overhanging vegetation, and aquatic macrophytes. Using field survey data from EPA’s National Lakes Assessment, the authors examine the associations between physical habitat and lake level drawdown. Reductions in near-shore habitat complexity can therefore have deleterious impacts on the ecological integrity of lakes and their riparian areas. Complex physical habitat at these land-water interfaces promotes interchange of water, nutrients and energy and provides diverse habitat for aquatic and terrestrial organisms alike. Lake shoreline zones are hot-spots for biological diversity, ecological processes, and human activity. Population increases and climate change have great potential to lower lake and reservoir levels in many regions of the U.S. So if we’re scoping out a money market account with a spectacularly long drawdown recovery period, that might be indicative of other issues with the fund.Constructed reservoirs, natural lakes, and the streams feeding them serve as sources of water for human activities. Second, the longer a fund takes to recover from a peak-to-valley drawdown, the worse it tends to perform overall. If there are a ton of peak-to-valley drawdowns over a somewhat short period of time, or if those drawdowns are really really big, then we know we’re looking at a more volatile investment option. First, it helps us gauge the risk level of a particular fund. If we’ve had the fund for a long time-and we’re predominantly talking about mutual funds and money market accounts here-we’ll probably see multiple peak-to-valley drawdowns over the year. Whoa, are we trying to be poetic all of a sudden? Are we describing Britney Spears circa 2007? No, but that’s what we’re looking at when we talk about a “peak-to-valley drawdown”: the percentage decline in an investment fund from its highest high (its peak) to its lowest low (its valley) after that peak.
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