Intensive management and declines in soil nutrients lead to serious exotic plant invasion inEucalyptusplantations under successive short‐rotation regimes

Abstract

The ongoing expansion of Eucalyptus plantations is changing the development of the world's forests. But, it also threatens ecological security regionally and worldwide. The expansion effect on biodiversity and soil nutrients is a universal problem, which has always been heatedly debated. In order to evaluate the long‐term influence of intensive management of Eucalyptus plantations under successive short‐rotation regime on understory plant diversity, soil nutrients and Eucalyptus tree growth, we chose a chronosequence representing the first to the sixth rotation of Eucalyptus plantations arrayed in the major Eucalyptus plantation areas in southern China and analyzed plant diversity indices, composition of plant functional groups (PFGs), soil nutrient concentrations and Eucalyptus tree growth at the stand level. Our results reveal that intensive management exerts a long‐lasting negative effect on understory plant species diversity, soil nutrients and Eucalyptus tree growth over successive rotations. Changes in soil nutrient content related with C and P cycling and declines in soil total nitrogen and available phosphorus were related with understory PFGs degradation. Furthermore, the combination of declines in understory woody plants, grasses and soil N and P cycling indices led to serious exotic plant invasion in the understory. Our study suggests that serious alien plant invasions could threaten the biosecurity, soil and timber security in Eucalyptus plantations. We suggest that reducing management intensity, converting mono‐cultured Eucalyptus plantations into mixed plantations with indigenous tree species, and changing from successive short‐rotation to short‐, medium‐ and long‐term cyclic rotations are required to sustainably manage these plantations through improving plant diversity, restoring degraded soils and resisting plant invasions.

Effect of Land Use History on Biodiversity of Pine Plantations

“…One factor that might have contributed to the persistence of some forest specialist species in pine plantations in Central Chile, is the relatively low frequency of disturbances involved in their management. Any management decision leading to changes in rotation length could certainly affect the long term composition of the community, by influencing the likelihood of forest specialists to find suitable habitat (Sullivan et al, 2009;Gallé et al, 2016;Castaño-Villa et al, 2019) and by affecting the invasion rate of disturbance-adapted exotics (Zhou et al, 2019).…”

Global guidelines for the sustainable use of non-native trees to prevent tree invasions and mitigate their negative impacts

“…Tailored management practices should be followed in the case of planted forests with NNTs for bioenergy production (Short Rotation Forestry SRF, Short Rotation Coppice SRC): choosing new planting sites; mitigating negative impacts on biodiversity (Weih 2008;Framstad et al 2009;Vanbeveren and Ceulemans 2019); preventing spread into surrounding habitats e.g., using buffer zones (Crosti et al 2016); protecting hydrology (Christen and Dalgaard 2013); conserving landscape values; and planning for the restoration of the site after the cultivation cycle (Hardcastle et al 2006;Neary 2013;Caplat et al 2014). For example, experience with Eucalyptus plantations under intensive short-rotation regimes in China (Zhou et al 2020) suggests that, in the long term, the intensively managed monospecific plantations under short-rotations should be progressively converted into mixed plantations with short-, medium-and long-term rotations. This strategy could be accomplished by interplanting with high-value native tree species such as Castanopsis hystrix, Dalbergia odorifera, and Parashorea chinensis.…”

Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

“…As a fast-growing tree species, Eucalyptus has been introducing and promoting genetic improvement in many regions to produce large amounts of wood for economic development [1]. However, large-area planting and continuous-planting rotation of commercial Eucalyptus plantations have caused various problems, such as reduced species diversity and loss of soil nutrients, which threaten ecological and timber security regionally and worldwide [1][2][3][4][5].…”