A substantial share of the remaining tropical forest cover is represented by historically degraded fragments exposed to severe edge effects, where ruderal plants proliferate vigorously and may arrest succession. We tested climber plant cutting as strategy to restore a semideciduous tropical forest remnant that is dominated by ruderal climbers. We compared control (unmanaged) plots with plots subjected to climber cutting at 1-m height with recutting one (after 8 months) or three times (8, 24 and 36 months). We monitored: 1) tree and shrub biomass gain and canopy openness for three years; 2) tree and shrub growth and recruitment of regenerating seedlings for one year; and 3) planted seedling survival for two years. Climber cutting increased biomass gain by~51% for smaller trees and shrubs (1.58 ≤ dbh b 5 cm) only, regardless of the number of re-cuts. Canopy openness increased following climber cutting, but recovered after ten months due to rapid growth of the tree canopies. Growth of regenerating seedlings, but not abundance, was favored by climber cutting. Initial cutting of climbers enhanced survival of enrichment plantings, but this benefit declined with canopy re-occupation by tree foliage. Although longer-term research is needed, cutting ruderal climbers in degraded forest remnants was shown to be a promising approach to enhance forest regeneration and carbon sequestration, justifying its consideration in the restoration agenda as a complementary activity to increasing forest cover in former agricultural lands.

Organisms are adapted to their environment through a suite of anatomical, morphological, and physiological traits. These functional traits are commonly thought to determine an organism’s tolerance to environmental conditions. However, the differences in functional traits among co-occurring species, and whether trait differences mediate competition and coexistence is still poorly understood. Here we review studies comparing functional traits in two co-occurring tropical woody plant guilds, lianas and trees, to understand whether competing plant guilds differ in functional traits and how these differences may help to explain tropical woody plant coexistence. We examined 36 separate studies that compared a total of 140 different functional traits of co-occurring lianas and trees. We conducted a meta-analysis for ten of these functional traits, those that were present in at least five studies. We found that the mean trait value between lianas and trees differed significantly in four of the ten functional traits. Lianas differed from trees mainly in functional traits related to a faster resource acquisition life history strategy. However, the lack of difference in the remaining six functional traits indicates that lianas are not restricted to the fast end of the plant life–history continuum. Differences in functional traits between lianas and trees suggest these plant guilds may coexist in tropical forests by specializing in different life–history strategies, but there is still a significant overlap in the life–history strategies between these two competing guilds.

Lianas reduce tree growth, reproduction, and survival in tropical forests. Liana competition can be particularly intense in isolated forest fragments, where liana densities are high, and thus, host tree infestation is common. Furthermore, lianas appear to grow particularly well during seasonal drought, when they may compete particularly intensely with trees. Few studies, however, have experimentally quantified the seasonal effects of liana competition on multiple tree species in tropical forests. We used a liana removal experiment in a forest fragment in southeastern Brazil to test whether the effects of lianas on tree growth vary with season and tree species identity. We conducted monthly diameter measurements using dendrometer bands on 88 individuals of five tree species for 24 months. We found that lianas had a stronger negative effect on some tree species during the wet season compared to the dry season. Furthermore, lianas significantly reduced the diameter growth of two tree species but had no effect on the other three tree species. The strong negative effect of lianas on some trees, particularly during the wet season, indicates that the effect of lianas on trees varies both seasonally and with tree species identity.