A Survey of Aquatic Invertebrate Communities in Nebraska Sandhill Lakes Reveals Potential Alternative Ecosystem States

Abstract Aquatic invertebrate communities are important to shallow lake ecosystem form and function, providing vital components to the food web and thereby important to achieving lake management goals. We characterized lake invertebrate communities and physicochemical variables in six Nebraska Sandhill lakes and examined these characteristics within an alternative stable state framework. Surveys were conducted during 2005 within each of these lakes by sampling aquatic macroinvertebrate abundance, zooplankton abundance and biomass, phytoplankton biomass, and physicochemical variables. When placed within an alternative stable state framework, the response variables exhibited a gradient of different ecosystem states. Two lakes appeared congruent with the clear water state (dense submergent vegetation, high invertebrate abundance and diversity, and low phytoplankton), two lakes were congruent with the turbid water state (high phytoplankton, low vegetation coverage, and low invertebrate abundance and diversity), and two lakes were intermediate, likely in a state of hysteresis (i.e., multiple states under equal environmental conditions). Principal component groupings further supported these findings by following similar lake-specific patterns with attributes of each stable state grouping meaningfully according to the observed lake states. The lakes contained varied fish communities, potentially influencing many measured metrics, through a top-down mechanism. Generally, lakes dominated by piscivorous fish displayed the clear water state, whereas lakes with abundant planktivores displayed the turbid water state. Shallow lakes containing dense invertebrate communities likely provide a rich food base to important fauna (migratory waterfowl) that aid in reaching desired management objectives for these systems. Multiple small lakes, in proximity, displaying divergent ecosystem states invites the opportunity for more in-depth analyses of driving mechanisms that will undoubtedly add to our ability to effectively manage these systems in the future.

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Phytoplankton response to fish-induced environmental changes in a temperate shallow pond-type lake

Archives of Polish Fisheries ◽

10.1515/aopf-2017-0020 ◽

2017 ◽

Vol 25 (4) ◽

pp. 211-262 ◽

Cited By ~ 4

Author(s):

Agnieszka Napiórkowska-Krzebietke

Keyword(s):

Phytoplankton Biomass ◽

Environmental Changes ◽

Silver Carp ◽

Ecological Status ◽

Ctenopharyngodon Idella ◽

Predatory Fish ◽

Turbid Water ◽

Clear Water ◽

Water State ◽

Pond Type

AbstractSince 1967, the temperate, shallow, pond-type Lake Warniak has been subjected to different biomanipulation methods including the introduction of common carp,Cyprinus carpioL., grass carp,Ctenopharyngodon idella(Val.), silver carp,Hypophthalmichthys molitrix(Val.), and bighead carp,Hypophthalmichthys nobilis(Richardson) and then their removal in an effort to control macrophytes and phytoplankton. Recently, pilot stocking with predatory fish, particularly pike,Esox luciusL., has also been conducted. Hence, an examination of the long-term response patterns of phytoplankton to multiple fish-induced stressors was undertaken. In recent years,Charadomination (2000-2004) has helped to stabilize a clear-water state, high/good ecological status, and meso-eutrophic conditions. After the disappearance of Charales in 2004, the rapid, unstable changes in phytoplankton biomass, structure, and biodiversity suggested a shift toward a turbid-water state. As a result, the phytoplankton assemblages changed from those dominated by cryptophytes Y+X2+X1+LO(2000-2004) through those dominated by cyanobacteria K (2005-2008), dinoflagellates LO+Y (2009-2011), and cryptophytes Y+LO+F+X2 (2012), to those dominated by diatoms D+K+P+A (2013-2014) with representative taxa that occur in nutrient-rich and/or nutrient-poor water bodies. The 1967-2014 changes indicated that four periods, two with clear-water state and two with turbid-water state, alternately, one after the other, resulted from different fish pressure. Higher autochthonous fish biomass was usually accompanied by lower phytoplankton biomass. In contrast, the introduction of Cyprinidae fish had a stimulating effect on summer phytoplankton dominated by cyanobateria. Among the nutrients, only phosphorus played an important role.

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Distribution of planktonic crustaceans and its diurnal changes in a hypertrophic shallow lake: does the switch from turbid-water state to clear-water state matters?

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2017021 ◽

2017 ◽

Vol 53 ◽

pp. 369-376

Author(s):

Wojciech Pęczuła ◽

Tomasz Mieczan ◽

Monika Tarkowska-Kukuryk

Keyword(s):

Shallow Lake ◽

Diurnal Changes ◽

Turbid Water ◽

Clear Water ◽

Water State ◽

Planktonic Crustaceans

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Aquatic Invertebrate Abundance in Relation to Changing Marsh Vegetation

The American Midland Naturalist ◽

10.2307/2424396 ◽

1976 ◽

Vol 95 (2) ◽

pp. 313 ◽

Cited By ~ 98

Author(s):

David K. Voigts

Keyword(s):

Aquatic Invertebrate ◽

Marsh Vegetation ◽

Invertebrate Abundance

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Large herbivores suppress liana infestation in an African savanna

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2101676118 ◽

2021 ◽

Vol 118 (41) ◽

pp. e2101676118

Author(s):

Tyler C. Coverdale ◽

Ryan D. O’Connell ◽

Matthew C. Hutchinson ◽

Amanda Savagian ◽

Tyler R. Kartzinel ◽

...

Keyword(s):

Stable State ◽

Life Forms ◽

Tree Canopy ◽

Alternative Stable State ◽

African Savanna ◽

Large Herbivore ◽

Large Herbivores ◽

Woody Vines ◽

Plant Life Forms ◽

Canopy Area

African savannas are the last stronghold of diverse large-mammal communities, and a major focus of savanna ecology is to understand how these animals affect the relative abundance of trees and grasses. However, savannas support diverse plant life-forms, and human-induced changes in large-herbivore assemblages—declining wildlife populations and their displacement by livestock—may cause unexpected shifts in plant community composition. We investigated how herbivory affects the prevalence of lianas (woody vines) and their impact on trees in an East African savanna. Although scarce (<2% of tree canopy area) and defended by toxic latex, the dominant liana, Cynanchum viminale (Apocynaceae), was eaten by 15 wild large-herbivore species and was consumed in bulk by native browsers during experimental cafeteria trials. In contrast, domesticated ungulates rarely ate lianas. When we experimentally excluded all large herbivores for periods of 8 to 17 y (simulating extirpation), liana abundance increased dramatically, with up to 75% of trees infested. Piecewise exclusion of different-sized herbivores revealed functional complementarity among size classes in suppressing lianas. Liana infestation reduced tree growth and reproduction, but herbivores quickly cleared lianas from trees after the removal of 18-y-old exclosure fences (simulating rewilding). A simple model of liana contagion showed that, without herbivores, the long-term equilibrium could be either endemic (liana–tree coexistence) or an all-liana alternative stable state. We conclude that ongoing declines of wild large-herbivore populations will disrupt the structure and functioning of many African savannas in ways that have received little attention and that may not be mitigated by replacing wildlife with livestock.

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Path-dependent institutions drive alternative stable states in conservation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1806852116 ◽

2018 ◽

Vol 116 (2) ◽

pp. 689-694 ◽

Cited By ~ 9

Author(s):

Edward W. Tekwa ◽

Eli P. Fenichel ◽

Simon A. Levin ◽

Malin L. Pinsky

Keyword(s):

Renewable Resources ◽

Path Dependence ◽

Alternative Stable States ◽

Stable State ◽

Empirical Support ◽

Stable States ◽

Alternative Stable State ◽

Important Challenge ◽

Quantitative Analyses ◽

Path Dependent

Understanding why some renewable resources are overharvested while others are conserved remains an important challenge. Most explanations focus on institutional or ecological differences among resources. Here, we provide theoretical and empirical evidence that conservation and overharvest can be alternative stable states within the same exclusive-resource management system because of path-dependent processes, including slow institutional adaptation. Surprisingly, this theory predicts that the alternative states of strong conservation or overharvest are most likely for resources that were previously thought to be easily conserved under optimal management or even open access. Quantitative analyses of harvest rates from 217 intensely managed fisheries supports the predictions. Fisheries’ harvest rates also showed transient dynamics characteristic of path dependence, as well as convergence to the alternative stable state after unexpected transitions. This statistical evidence for path dependence differs from previous empirical support that was based largely on case studies, experiments, and distributional analyses. Alternative stable states in conservation appear likely outcomes for many cooperatively managed renewable resources, which implies that achieving conservation outcomes hinges on harnessing existing policy tools to navigate transitions.

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Structural Complexity and Distance from Source Habitat Determine Invertebrate Abundance and Diversity

Biotropica ◽

10.1111/j.1744-7429.2011.00762.x ◽

2011 ◽

Vol 43 (6) ◽

pp. 738-745 ◽

Cited By ~ 21

Author(s):

Roger P. Mormul ◽

Sidinei M. Thomaz ◽

Alice M. Takeda ◽

Rômulo D. Behrend

Keyword(s):

Structural Complexity ◽

Invertebrate Abundance ◽

Abundance And Diversity

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Wildfire induced changes in aquatic invertebrate communities and mercury bioaccumulation in the Okefenokee Swamp

Hydrobiologia ◽

10.1007/s10750-011-0694-4 ◽

2011 ◽

Vol 669 (1) ◽

pp. 237-247 ◽

Cited By ~ 13

Author(s):

Sarah R. Beganyi ◽

Darold P. Batzer

Keyword(s):

Aquatic Invertebrate ◽

Invertebrate Communities ◽

Okefenokee Swamp ◽

Mercury Bioaccumulation ◽

Induced Changes

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Uncertain ecosystems: the conceptual framework

Open Ecosystems ◽

10.1093/oso/9780198812456.003.0003 ◽

2019 ◽

pp. 27-42

Author(s):

William J. Bond

Keyword(s):

Trophic Ecology ◽

Resource Constraints ◽

Stable State ◽

State Theory ◽

Tree Cover ◽

Top Down ◽

Alternative Stable State ◽

Positive Feedbacks ◽

Vegetation Models ◽

Global Vegetation

Climate sets the potential biomass of trees and physiologists have made considerable progress in understanding and predicting that potential and applying it in global vegetation models. The problem is in understanding and predicting tree cover where it is far from the climate potential. Vast areas of non-forested vegetation occur where climates are suitable for forests. Arguments over why forests are absent, ongoing for over a century, are generally polarized between favouring bottom-up factors (resource constraints) or top-down factors (herbivory, predation, fire). There is increasing support for hypotheses invoking the interaction between the two. This chapter introduces the key hypotheses, their assumptions and predictions. Trophic ecology is a useful framework for exploring departures from the climate potential for trees, focussing explicitly on regulation by consumers, including fire. Alternative stable state theory is emerging as particularly appropriate for explaining forest/non-forest mosaics with each state maintained by positive feedbacks to the preferred environment.

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Debris dams as habitat for aquatic invertebrates in forested headwater streams: a large-scale field experiment

Marine and Freshwater Research ◽

10.1071/mf18216 ◽

2019 ◽

Vol 70 (5) ◽

pp. 734

Author(s):

Brenda R. Baillie ◽

Brendan J. Hicks ◽

Ian D. Hogg ◽

Michael R. van den Heuvel ◽

Mark O. Kimberley

Keyword(s):

Large Scale ◽

Aquatic Invertebrates ◽

Headwater Streams ◽

Dam Removal ◽

Aquatic Invertebrate ◽

Invertebrate Communities ◽

Debris Dams ◽

Scale Field ◽

Large Scale Field ◽

Debris Dam

To evaluate the effects of debris dams on aquatic invertebrate communities, we sampled benthic invertebrates in debris dams and riffles in three forested headwater streams in New Zealand. As part of a large-scale field experiment, debris dams were subsequently removed from three treatment sections in each of the streams to assess effects on invertebrate communities. Prior to debris dam removal, total invertebrate densities in debris dams were not significantly different from those in riffles. However, densities of Ephemeroptera, Plecoptera and Trichoptera taxa were significantly higher in debris dams than in riffles. Debris dams contained a higher number of less common taxa (defined as <1% of total catch) and significantly higher densities of shredders. Densities for Coleoptera, Diptera and Trichoptera taxa were significantly higher in the autumn than in the spring. Non-metric multidimensional scaling axis scores indicated that both habitat and season had a significant effect on aquatic invertebrate community composition. At the reach scale, the effects of debris dam removal on the aquatic invertebrate communities were not statistically detectable because debris dams comprised only a small proportion of total habitat. However, these data highlight the importance of debris dams in contributing to the diversity of aquatic invertebrates in forested headwater streams.

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