Recovery after 25 years of the tree and palms species diversity on a selectively logged forest in a Venezuelan lowland ecosystem

Abstract

Aim of the study: We evaluate palm and tree species diversity in a floodplain forest and the changes affecting the plots subjected to different intensities of selective logging.Area of study: The western alluvial plains of Venezuela. Materials and Methods:A randomized complete blocks design was established 25 years ago with three felling treatments (trees with diameter greater than 20 cm, 40 cm and 60 cm). Each treatment had three replications, using 1 ha permanent plots. We have measured all trees and palms bigger than over 10 cm in diameter. The data set was used to calculate the Importance Value Index of each species, the Shannon-Wiener index, the Hill Numbers and the Chao-Sørensen index.Main results: Disturbance increases the importance value index of pioneer species like Cecropia peltata, Ochroma pyramidale and Triplaris americana. All treatments produce changes on the floristic diversity but most of them are not significant. Only the high impact treatment causes a decrease in the species richness, but after 5 year of recovery this parameter is close to its previous levels (N0= 43.5). In logged forests, species loss (9.2%) is lower than in the control plots (11.7%) and is also lower than the rate of occurrence of species input (14.6%).Research highlights: In these logged forests restoration of diversity is acceptable because is higher than 91% (Chao-Sørensen index). Selective logging, with low and medium intensity, is a disturbance that works in a similar way to natural disturbances. All the diversity indexes recovered the pre-harvest level values.Keywords: Caparo -Venezuela; ecological restoration; forest dynamics; forest management; forest succession; Intermediate Disturbance Hypothesis; permanent plots.Citation: Lozada, J.R., Arends, E., Sánchez, D., Villarreal, A., Guevara, J., Soriano, P., Costa, M. (2016). Recovery after 25 years of the tree and palms species diversity on a selectively logged forest in a Venezuelan lowland ecosystem. Forest Systems, Volume 25, Issue 3, e066. http://dx

The Valuation of Thinning Efectivity Based on Increment Respond of Natural Forest Log Over Area

“…It shows that the stand's growth pattern is an ecophysiological function, including the influence of the given treatment [2], [14]. The number of trees and stand structures that describe the level of stand availability at each stand growth stage influences the regeneration ability or growth of stands [5], [8], [14], [19].…”

“…The growth of individual trees or stand resulted from total interaction from genetic traits and their environment. The difference in the pattern of growth of the same species at the same location is greatly influenced by ecophysiological factors [1], [8]- [9]. The growth response of individual trees based on growth space will form different growth of stands [4], [10]- [11].…”

Carbon Emissions from Deforestation and Degradation in a Forest Reserve in Venezuela between 1990 and 2015

“…In addition, riparian pockets of different forest types associated with permanent and/or semi-permanent streams and the Caparo River as the major watercourse can still be found in the area. Finally, an approximate section of 7,000 ha to the West of the reserve allocated to an experimental area with a research-oriented management remains as on the last relicts of the seasonal forests of the Western Plains bioregion [53], where close to one third of the area can be still be considered as a relatively mature old-growth forest with important implications for biodiversity conservation and other ecosystem services. The methodological approach used in our study is based upon the guidelines proposed by the IPCC guide for good practices [17,44,55], which combines the Activity Data with the Emission Factors (EF).…”

“…The field plots in our study can be classified in two groups. The first one established between 1989 and 1990 and consist of 34 rectangular plots of 1000 m long by 10 m wide (1 ha transects) (Appendix A.3), systematically distributed trying to cover soil variations that are typical for alluvial systems [53]. The second group consist of six 0.25 ha plots (50 × 50 m) that were established between 1991 and 1996.…”

“…(2) Since our field plots are located in an undisturbed area, we used the studies of Kammesheidt [48], and Lozada et al [53] as a baseline for the impact of logging on AGB in CFR managed forests. Per these, immediately after harvest, conventional logging can reduce 40-60% of the total basal area conditioned to several factors including logging intensity (number of trees harvested) and spatial distribution of commercial species.…”