Plantation age, understory vegetation, and species‐specific traits of target seedlings alter the competition and facilitation role of Eucalyptus in South China

Abstract

The Chinese government is considering ways to reconstruct Eucalyptus plantation monocultures in order to improve their ecosystem services. However, the effects of competition or facilitation of Eucalyptus on native species during the reconstruction have not been identified, especially during the formation of novel ecosystems. To better understand these relationships, in this study we tested the effects of competition and facilitation of Eucalyptus on three target species (Schima superba, Michelia macclurei, and Castanopsis fissa), in Eucalyptus plantations with different ages and understory vegetation. The results showed that the survival and growth of S. superba and M. macclurei were not sensitive to plantation age and understory removal treatment. The survival of C. fissa in understory removal was significantly higher and the growth of C. fissa increased gradually with increasing plantation age. The relative neighbor effect (RNE) index for growth indicated that the relationship between Eucalyptus and target species switched from competition to facilitation with an increase in plantation age. A redundancy analysis (RDA) showed that survival was positively correlated with soil water content and soil phosphorus. Growth was positively correlated with soil organic matter and soil nitrogen and negatively correlated with soil bulk density. Our results indicate that plantation age, understory vegetation, and species‐specific traits of target seedlings could change the competition and facilitation roles of Eucalyptus. Higher survival and growth rates indicated that C. fissa was an appropriate species for the reconstruction of mature Eucalyptus plantations and understory removal will benefit the process.

Species Identity and Initial Size Rather Than Neighborhood Interactions Influence Survival in a Response-Surface Examination of Competition

“…Previous studies have shown that very shade-tolerant species lack alternative mechanisms to cope with excess light energy and are more likely to incur photoinhibitory damage to their photosynthetic apparatus (Rodrıǵuez-Calcerrada et al, 2006). Therefore, C. fissa seedlings had a distinct photoinhibition which reduced carbon assimilation and growth under high radiation in open sites (Yang et al, 2010;Sun Z. et al, 2017). In agreement with the previous studies (Uriarte et al, 2004;Wang et al, 2012;Pu et al, 2017), we found a significantly positive relationship between initial size and seedling survival ( Figures 4A-E).…”

“…Previous studies have shown that very shade-tolerant species lack alternative mechanisms to cope with excess light energy and are more likely to incur photoinhibitory damage to their photosynthetic apparatus ( Rodríguez-Calcerrada et al., 2006 ). Therefore, C. fissa seedlings had a distinct photoinhibition which reduced carbon assimilation and growth under high radiation in open sites ( Yang et al., 2010 ; Sun Z. et al., 2017 ).…”

How to Bloom the Green Desert: Eucalyptus Plantations and Native Forests in Uruguay beyond Black and White Perspectives

“…We evaluated plantations and native forests beyond black and white perspectives in order to provide insights for developing multifunctional landscape forests. For instance, these forests can be developed to guide toward a species selection for mixed-species systems of native species within Eucalyptus plantations [39] or manage plantations as nurse systems for restoration purposes [40,41]. This is crucial, especially for countries with landscapes where Eucalyptus plantations are already widely established and acknowledged as an important economic sector by national stakeholders [38,42].…”

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

“…This could be accomplished by interplanting with indigenous tree species such as Betula alnoides, Schima superba, Michelia macclurei, and Castanopsis fissa (Sun, Huang, Yang, Schaefer, & Chen, 2017;Williams, 2015). This could be accomplished by interplanting with indigenous tree species such as Betula alnoides, Schima superba, Michelia macclurei, and Castanopsis fissa (Sun, Huang, Yang, Schaefer, & Chen, 2017;Williams, 2015).…”

“…In the long term, the current management should be converted from stand level with pure plantations under successive short-rotations into landscape level with mixed plantations under short-, medium-and long-term cyclic rotations. This could be accomplished by interplanting with indigenous tree species such as Betula alnoides, Schima superba, Michelia macclurei, and Castanopsis fissa (Sun, Huang, Yang, Schaefer, & Chen, 2017;Williams, 2015). We especially recommend high-value native tree species such as Castanopsis hystrix, Dalbergia odorifera and Parashorea chinensis .…”