Biological barriers to restoration: testing the biotic resistance hypothesis in an upland stream recovering from acidification

Abstract

The biotic resistance hypothesis provides one of several explanations for the limited biological recovery of streams recovering chemically from acidification. The hypothesis proposes that acidification has changed the presence, abundance and interactions among species in acidified streams to the extent that acid-sensitive colonists cannot re-invade even where acidity has ameliorated. As a first step in testing for biotic resistance in streams, we conducted a field experiment to determine whether the success (growth rate) of acid-sensitive recolonists (mayfly nymphs, Baetis rhodani) is reduced by competition with abundant acid-tolerant residents (stonefly nymphs, Leuctra inermis) in a chemically recovering Welsh stream (UK). Gut contents analysis revealed a marked overlap in resource use between the two species. However, when Baetis was exposed to several (0, 0.25, 0.5 and 1 times ambient) densities of its putative competitor, Leuctra, growth rates of the colonist were not affected by the residents at any of the densities tested. These results do not support the hypothesis that resident species constrain colonist populations by affecting growth rates through competition for limited resources or interference. Further work is required to assess whether independent and/or interactive ecological effects of other common residents might affect colonists in ecosystems recovering from past stressors.

The use of palaeoecological and contemporary macroinvertebrate community data to characterize riverine reference conditions

“…These conservation management goals directly reflect the current policy aspirations outlined for freshwater habitats in England (Mainstone et al, ). However, there may be a number of ecological barriers to restoration including dispersal limitation, abiotic resistance, resource limitation, and biotic resistance, which may reduce the success and effectiveness of increasing habitat complexity (Frame, Jones, Ormerod, Sadler, & Ledger, ; Palmer et al, ).…”

Mild cycles open closed communities to ecological restoration

“…In the literature, the problem of resistance to recovery or to (re‐)invasion has been addressed using a variety of terms that have (slightly) different meanings but that are closely related. It is useful to be aware of these different phrases that include community closure (Lundberg et al ), biotic resistance (Frame et al ), invasion resistance (Shea & Chesson ), community saturation (Loreau ), negative resistance (Lake ), and resistance of the degraded state to restorative interventions (Lake ). In invasion ecology the concept of niche opportunities has been used to address invasion success (or failure) in response to the availability of resources and the abundance of natural enemies (Allington et al ).…”

“…We mean all three terms to be effects of biological interactions. We like the term biotic resistance as used by Frame et al () in relation to restoration, but we have chosen not to use it as such, as the term is also often used for community resistance to exotic species in the literature on invasive species.…”

“…It is not easy to distinguish or disentangle the effects of e.g. dispersal limitation, abiotic conditions, and biotic interactions and several might jointly contribute to reassembly failure (Vinebrooke et al ; Ledger & Hildrew ; Frame et al ). Restoration measures traditionally often focus on the dispersal side of the problem (e.g.…”

Experimental Investigation into Disturbance of Ca-Mg Equilibrium and Consequences for Charophytes after Iron and Aluminium Coagulants Application

“…Finally, aggregate-flocs are formed with a large absorptive surface as a result of coagulation and flocculation processes [13]. Although this process is very effective, acidification poses a threat to hydrobiota [14].…”