Trophic linkages between headwater forests and downstream fish habitats: implications for forest and fish management

Wipfli, Mark S.

doi:10.1016/j.landurbplan.2004.09.025

Cited by 24 publications

(26 citation statements)

References 41 publications

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“…The importance of headwater streams to the trophic basis for downstream assemblages has not been quantified. We and others (Cummins and Wilzbach, 2005; Wipfli, 2005) hypothesize that headwater streams contribute significantly to downstream productivity. The importance of headwater exports is likely accentuated where small streams feed rivers in which local secondary production is depressed by effects of flow alteration (e.g., by upstream dams that cause extreme flow fluctuations or limit floodplain inundation), sediment loading from landscape disturbance (current or historic; Waters, 1995) and loss of migratory fauna because of downstream dams (Freeman et al.…”

Section: Regional Ecosystem Response To Headwater Stream Alterationmentioning

confidence: 83%

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹

Freeman

Pringle

Jackson

2007

J American Water Resour Assoc

485

293

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Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water‐mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two‐thirds of total stream length in a typical river drainage and directly connect the upland and riparian landscape to the rest of the stream ecosystem. Altering headwater streams, e.g., by channelization, diversion through pipes, impoundment and burial, modifies fluxes between uplands and downstream river segments and eliminates distinctive habitats. The large‐scale ecological effects of altering headwaters are amplified by land uses that alter runoff and nutrient loads to streams, and by widespread dam construction on larger rivers (which frequently leaves free‐flowing upstream portions of river systems essential to sustaining aquatic biodiversity). We discuss three examples of large‐scale consequences of cumulative headwater alteration. Downstream eutrophication and coastal hypoxia result, in part, from agricultural practices that alter headwaters and wetlands while increasing nutrient runoff. Extensive headwater alteration is also expected to lower secondary productivity of river systems by reducing stream‐system length and trophic subsidies to downstream river segments, affecting aquatic communities and terrestrial wildlife that utilize aquatic resources. Reduced viability of freshwater biota may occur with cumulative headwater alteration, including for species that occupy a range of stream sizes but for which headwater streams diversify the network of interconnected populations or enhance survival for particular life stages. Developing a more predictive understanding of ecological patterns that may emerge on regional scales as a result of headwater alterations will require studies focused on components and pathways that connect headwaters to river, coastal and terrestrial ecosystems. Linkages between headwaters and downstream ecosystems cannot be discounted when addressing large‐scale issues such as hypoxia in the Gulf of Mexico and global losses of biodiversity.

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Section: Regional Ecosystem Response To Headwater Stream Alterationmentioning

confidence: 83%

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹

Freeman

Pringle

Jackson

2007

J American Water Resour Assoc

485

293

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“…For this reason, headwater streams are important to downstream ecological function (Gomi et al 2002;Lowe and Likens 2005;Wipfli 2005), and provide the best opportunity to assess the impacts of terrestrial invasive species on aquatic ecosystems. Headwater streams are typically dominated by allochthonous inputs derived from riparian zone forests (Vannote et al 1980;Iversen et al 1982;Lowe and Likens 2005), and these inputs and their decomposition products are important in structuring downstream communities (Vannote et al 1980;Fausch et al 2002;Gomi et al 2002;Wipfli 2005). As leaf fall provides the most important source of potential energy for headwater stream ecosystems, alteration of leaf fall biomass, nutrient content or timing may have important ecological impacts.…”

Section: Introductionmentioning

confidence: 99%

Rapid in-stream decomposition of leaves of common buckthorn (Rhamnus cathartica), an invasive tree species

Freund

Thobaben

Barkowski

et al. 2013

Journal of Freshwater Ecology

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Headwater streams derive a majority of their energy from allochthonous inputs; alteration of these inputs may lead to changes in stream communities and ecological function. Common buckthorn (Rhamnus cathartica) is invasive over much of the northern United States and southern Canada, and has the potential to become an ecosystem dominant and alter stream communities. However, while much is known of the effects of buckthorn on terrestrial ecosystems, little is known of its effects on aquatic ecosystems. Using leaf collection nets, we estimated that leaf fall to the stream consisted predominantly of green ash (69.0%) and common buckthorn (24.2%). Green ash leaves fell from September through mid-October, reaching its peak in early October, whereas common buckthorn contributed leaves for an additional month until mid-November. We placed leaf packs of common buckthorn and two native species, American elm and green ash, in a headwater stream to determine differences in leaf decomposition rates. Common buckthorn leaves decomposed more rapidly than the native species, with processing coefficients of 6.9 (ash) and 5.3 (elm) times greater. After 21 days of incubation, buckthorn leaf packs had less than half the initial biomass remaining, whereas ash and elm did not reach this point within this 84-day study. These results suggest that buckthorn has the potential to alter stream food webs by changing the timing of leaf fall and the duration of available allochthonous energy sources. Changes to riparian forests are likely to be exacerbated as common buckthorn alters soils to inhibit the growth of other trees and as the emerald ash borer, an invasive beetle, adversely affects native ash forests.

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“…), comprising 80% of total stream length (Dunne and Leopold ). As such, the headwater streams of a forest catchment are analogous to capillaries in a vertebrate circulatory system, comprising the interface between aquatic and terrestrial domains (Nakano and Murakami , Wipfli , Greene et al. ).…”

Section: Introductionmentioning

confidence: 99%

Metrics of disturbance in a redwood forest ecosystem: responses of stream amphibians to repeated sediment infusions

2019

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Disturbances are part of the natural dynamics of Earth's ecosystems, with these events more common now in the Anthropocene. Yet metrics for calibrating these impacts and measuring an ecosystem's capacity to recover are lacking. Highway construction in 1989 to bypass Prairie Creek Redwoods State Park in California resulted in storm‐driven infusion of exposed sediments into five streams; five nearby streams that were not intersected by the bypass construction were not affected by this event and served as controls for a natural experiment. A second large storm event in 1995 contributed sediment loads into all ten streams resulting in a disturbance gradient that allowed us to examine the effects of repeated sediment disturbances. We evaluated the impacts of these stresses on three resident stream amphibian species in 1990 and again in 1996. In 1990, the impacted streams had sixfold higher pool sediment loads and significantly lower larval tailed frog (Ascaphus truei) densities and lower densities of coastal giant salamanders (Dicamptodon tenebrosus) and southern torrent salamanders (Rhyacotriton variegatus) compared with the un‐impacted streams. During the six years between these storm events, pool bowl sediment loads increased 14‐fold in the previously un‐impacted streams and threefold in the previously impacted streams. Larval tailed frogs and torrent salamanders further declined in both sets of streams in 1996 although non‐significantly. In contrast, giant salamander densities increased in both stream sets. Of the three species, giant salamanders appeared the most resistant to the depositional events, while the other two species appeared to decline relative to the intensity of the sediment disturbances but still persist. We believe these results demonstrate the usefulness of these three amphibians as metrics for measuring the effects of this common disturbance type on the ecological resilience of stream networks in this and other temperate northwest forest ecosystems.

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Trophic linkages between headwater forests and downstream fish habitats: implications for forest and fish management

Cited by 24 publications

References 41 publications

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹

Rapid in-stream decomposition of leaves of common buckthorn (Rhamnus cathartica), an invasive tree species

Metrics of disturbance in a redwood forest ecosystem: responses of stream amphibians to repeated sediment infusions

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Trophic linkages between headwater forests and downstream fish habitats: implications for forest and fish management

Cited by 24 publications

References 41 publications

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales1

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales1

Rapid in-stream decomposition of leaves of common buckthorn (Rhamnus cathartica), an invasive tree species

Metrics of disturbance in a redwood forest ecosystem: responses of stream amphibians to repeated sediment infusions

Contact Info

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Resources

About

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹

Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales¹