Understanding the Impact of Biological Control on Melaleuca

Background

Melaleuca quinquenervia (pine-bark tree) is an invasive non-native tree that has spread over wide areas of the freshwater ecosystems of southern Florida. The effect of the Melaleuca snout beetle (bio-control) has been especially effective in decreasing allocation of resources to growth and reproduction, such that Melaleuca has lost its competitive advantage. See pictures below, before and after application of biocontrol.

Melaleuca quinquenervia

1996-note very very dense melaleuca forest at the same site.

Photo from Dr. Min B. Rayamajhi

2007.1- open canopy, some newly migrated species under melaleuca canopy, few clumps of sawgrass, most composites like Baccharis species.
Photo from Dr. Min B. Rayamajhi

2007.2- Note fallen trees due to defoliation, dieback, shrunken root mass- open canopy, migration of new species under melaleuca canopy.
Photo from Dr. Min B. Rayamajhi

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Part I

Simulate the impact of bio-control on Melaleuca in south Florida by using an individual-based forest model 2014-2016

This work is collaborated with folks in USDA invasive plants laboratory, especially Dr. Min B. Rayamajhi, Dr. Dan Botkin. It is funded by USGS's Greater Everglades Priority Ecosystem Science funding.

 

Goal

The goal of this study is to understand the plant community changes that occurred with the introduction of ​Melaleuca and the changes that are now occurring in Melaleuca-dominated areas with the introduction of bio-control, as well as to project future changes that might be expected over the next decades.

 

 

Main Results

Computer simulations show melaleuca invasion leads to decreases in density and basal area of native species, but herbivory would effectively control melaleuca to low levels, resulting in a recovery of native species.

 

Relevant Presentations

• Oct 2016 – 10th INTECOL international Wetlands Conference, Changshu, China.
• May 2016 - The international Society for Ecological Modeling Global Conference, Baltimore, MA, USA.
• Apr 2016 – National Conference on Ecosystem Restoration (NCER), Coral Springs, FL, USA
• Nov 2015 – BIL 149 Guest Speaker, Department of Biology, University of Miami.
• Aug 2015 - 100th Ecological Society of America Annual meeting, Baltimore, MA.
• Apr 2015 - Greater Everglades Ecosystem Restoration (GEER), Coral Springs, FL, USA. 

Relevant Publications

• Zhang, B., D. L. DeAngelis, M. B. Rayamajhi, D. Botkin. In press Projecting the effects of biocontrol on Melaleucaquinquenervia in southern Florida using individual-based modeling. Landscape Ecology. DOI: 10.1007/s10980-017-0519-6​

Some popular press on this research: USGS_Wetlands: New modeling study suggests introduced insect herbivores could help control the invasive tree melaleuca in long-term.

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Part II

Plant Compensation and the Effects of Biocontrol Herbivory an Invasive Plant​
​2016-2017

This work is collaborated with folks in USDA invasive plants laboratory, Dr. Shu Ju. It is funded by USGS's Greater Everglades Priority Ecosystem Science funding.

 

Objective

The main objective of this study is to use a nutrient and carbon allocation model to simulate and theoretically understand the process of how Melaleuca should optimally adapt its strategy of carbon and nutrient allocation in response to the impact of biological control.

Schematic of model for allocation of carbon and for nutrient cycling. This model is based on a model developed by DeAngelis et al. (2012), which was based on the earlier G'DAY model of Comins and Mcmurtie (1993).
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I used a model to understand:

1. How Melaleuca should optimally respond to biological control, altering its allocations of nutrient and carbon to compensatory foliage production.
2. The effects of different biological control types, density and soil type on Melaleuca reproduction and growth.

Relevant Publications

• Zhang, B., X. Liu, D. L. DeAngelis, L. Zhai, M. B. Rayamajhi, S. Ju. Plant Compensation and the Effects of Biocontrol Herbivory an Invasive Plant. In press Biological Control.