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Updated: May 13, 2026
10:16
Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling
Published on: January 16, 2014
Increased nitrogen cycling facilitates native forest regeneration: potential for restoring extinct ecological
Andrew J Tanentzap1, William G Lee, Adrian Monks
1Landcare Research, 764 Cumberland Street, Private Bag 1930, Dunedin 9054, New Zealand. tanentzapa@landcareresearch.co.nz
Summary
Simulating extinct New Zealand birds
Area of Science:
- Ecology
- Restoration Ecology
- Forest Ecology
Background:
- Ecological processes maintain native plant communities, and their disruption can facilitate non-native species invasions.
- The loss of extinct megafauna, like New Zealand's avian megafauna, may alter ecosystem functions and community dynamics.
- Understanding the role of these extinct species is crucial for effective ecological restoration and conservation.
Purpose of the Study:
- To simulate the ecological effects of extinct avian megafauna on woody plant regeneration and non-native species invasion in a New Zealand temperate rainforest.
- To investigate the impact of simulated fecal deposition (nitrogen and phosphorus enrichment) and soil turnover on native and non-native seedling establishment.
- To assess the relationship between nutrient cycling, specifically nitrogen availability, and the invasibility of forest plant communities.
Main Methods:
- Experimental simulation of avian megafauna impacts using hen manure (fecal deposition) and liquid fertilizer treatments.
- Measurement of soil nutrient levels (nitrate-N and phosphorus) and seedling densities (native and non-native woody plants).
- Analysis of the influence of simulated soil disturbance and nutrient enrichment on plant regeneration and community invasibility.
Main Results:
- Hen manure application significantly increased soil nitrate-N and promoted greater native seedling regeneration compared to control plots.
- While soil phosphorus increased with hen manure, liquid fertilizer treatments did not yield similar increases in seedling density.
- Simulated soil disturbance did not affect seedling densities, and none of the treatments altered the proportion of non-native woody seedlings.
- Pre-existing variation in soil nitrate-N availability, indicative of nitrogen cycling rates, was found to reduce community invasibility.
Conclusions:
- Avian-derived nitrogen inputs play a significant role in enhancing native forest regeneration.
- The functional role of extinct megaherbivores in nutrient cycling and community regulation may be missing in contemporary New Zealand ecosystems.
- Further research is needed to fully understand the long-term consequences of megafauna absence on forest dynamics and resilience to invasion.
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