New paper - Multi-site bracken control study

[Glyn Young]

Drop me a line if you’d like an electronic copy of this paper. Glyn glyn....@durrell.org

 

Journal of Applied Ecology

 

Overcoming resistance and resilience of an invaded community is necessary for effective restoration: a multi-site bracken control study

 

Josu G. Alday, Emma S. Cox, Robin J. Pakeman, Mike P. K. Harris, Mike G.Le Duc and Rob H. Marrs

 

Summary

 

1. The search for appropriate management strategies to control invasive plants is an important

theme in environmental management. However, the recovery of the resident community

species complement does not necessarily respond predictably to restoration efforts. Increasing

restoration success requires an understanding of the resistance and resilience of the invaded

community and the response of the newly developing community to management. Here, we

used Pteridium-invaded heath and grass communities as a test system and investigated the

effects of recommended Pteridium aquilinum control treatments on vegetation composition

and diversity.

 

2. We evaluated seven field experiments in four regions of Great Britain designed to test five

Pteridium control treatments, including ‘one-off’ (applied only at the start) and ‘repeated’

(applied regularly) treatments, against an untreated experimental control. The sites had context-

dependent restoration targets, either a Calluna heathland or acid grassland. Species cover

and diversity responses (higher plants, mosses plus lichens) to these treatments were monitored

annually for 10 years.

 

3. Pteridium control treatments induced significant change in species composition compared

to experimental controls in both vegetation types. On Calluna target sites, ‘repeated’ treatments

overcame the resistance of the invaded community producing a gradual divergence in

species composition and species diversity. In contrast, the ‘one-off’ treatments were

ineffective.

 

4. At the acid grassland target sites, all treatments overcame the resistance of the Pteridium dominated

state producing changes in species composition in comparison with experimental

controls.

 

5. Synthesis and applications. There are two important results for land managers: (i) where

Calluna heathland is the target, ‘repeated’ treatments (cutting once or twice per year) were

effective in overcoming the resistance of invaded community and moving species composition

towards the target state, effectively creating an alternative state; (ii) where acid grassland is

the target both ‘one-off’ and ‘repeated’ treatments overcame the invaded community resistance

(‘one-off’ also overcame resilience) producing changes in species composition in the

desired direction. The effectiveness of ‘one-off’ treatments was site dependent and produced

alternative stable states within 10 years. In contrast, ‘repeated’ treatments were site independent

but took longer to work and were more expensive.

 

Key-words: acid grassland, Calluna heathland, long-term monitoring, principal response

curves, Pteridium aquilinum, species richness

=====================================================================
This email has been scanned and is free of viruses and malware.
=====================================================================