Eucalyptus Are Unlikely to Escape Plantations and Invade Surrounding Forests Managed with Prescribed Fire in Southeastern US

Abstract

Woody biomass production can increase through establishment of non-native tree species exhibiting greater growth potential than traditional native species. Interest in growing Eucalyptus in the southeastern US has raised concern over its potential spread and invasion, which could impact ecosystem properties and functions. Within the matrix of land use where Eucalyptus establishment is being considered in the southeastern US, surrounding pine forests managed with fire represent a likely pathway for invasion. We used greenhouse and field experiments to evaluate the potential invasion risk of Eucalyptus benthamii. We were specifically interested in determining if seeds could successfully germinate in fire-maintained pine forests and if fire-return intervals influenced germination through impacts on litter accumulation and light availability. The greenhouse experiment investigated the influence of light availability on germination success, whereas the field study investigated the influence of time since fire, and thus litter accumulation and light availability, on germination success. Percent germination was similar under non-shaded controls and moderate shade, but complete shade resulted in low germination rates. Germination was lower in the field compared to the greenhouse and was influenced by litter and light availability, which varied according to fire-return intervals. Litter increased, and light availability decreased, with time since burn. Germination was negatively related to litter depth and positively related to light availability, thereby decreasing with time since fire. Germination increased with litter removal but remained positively related to light availability after litter removal. Higher germination with litter removal suggests germination is influenced by litter, but higher germination with increased light availability, regardless of raking, suggests germination is also influenced by light availability. Despite these relationships, no seedlings persisted through the growing season. The low germination rates under a variety of field conditions coupled with the lack of persistence suggests establishment may be unlikely, regardless of the surrounding land matrix.

Estimating the Economic Values of Restricted Monoculture Eucalyptus Plantations: A Choice Modeling Approach

“…As a non-native species, the expansion of Eucalyptus can result in the transformation of the landscape and a change in the natural ecosystem. This finding is also in line with Toledo et al [ 60 ], who assessed the potential spread and invasive nature of Eucalyptus , which could impact ecosystem properties and functions…”

Effect of poplar ecological retreat project on soil bacterial community structure in Dongting Lake wetland

“…Monoculture of large-scale fast-growing tree plantations is considered to be one of the threats to biodiversity ( Kindlmann et al, 2017 ; Egoh et al, 2020 ). Generally, they are superior to native species in competition for water, light and nutrients ( Li et al, 2014b ; Toledo et al, 2020 ), which may lead to transformation or even disappearance of natural ecosystems ( Gardner et al, 2015 ; Sica et al, 2016 ). However，the use of fast-growing plantations is still widespread around the world to develop economies, meet landscape and other needs ( Fashing et al, 2012 ).…”