Point of (no) return? Vegetation structure and diversity of restored mangroves in Sulawesi, Indonesia, 14–16 years on

Abstract

Mangrove forests, benefitting millions of people, experience significant degradation. Global recognition of the urgency of halting and reversing this trend have initiated numerous restoration activities. Restoration success is typically evaluated by estimating mangrove survival and area restored, while diversity and structure of vegetation, as proxies for functional forests, are rarely considered. Here we assess mangrove species richness along sea‐landward transects and evaluate restoration outcomes by comparing number of mangrove species, relative species abundance, biomass, diameter, and canopy cover in “Monoculture Reforestation”, “Mixed Species Regeneration” and adjacent “Reference” forest stands, 14 (Tiwoho site) and 16 years (Likupang site) after restoration activities took place. In the “Monoculture Reforestation” plots, mangrove diversity and structure still closely reflected the original restoration actions, with only one and two “new” species having established among the originally densely planted “foundation” species. In contrast, the “Mixed Species Regeneration” plots were more similar to the “Reference” plots in terms of tree diameter and canopy coverage, but species number, abundance and biomass were still lower. The trajectory of the “Mixed Species Regeneration” plots suggests their similarity with the “Reference” stands will increase over time, whereas such “smooth” transition is unlikely to happen in the planted “Monoculture Reforestation” stands, in the foreseeable future. Implementing frequent small‐scale disturbances in restored forest management would increase stand structure and diversity, accelerating the establishment of a more natural, and likely more functional and resilient forest.

Tracking the long‐term vegetation and soil characteristics of restored mangroves: a case study from Guyana's coast

“…Avicennia germinans was the most dominant species, probably because it is well adapted to the saline conditions experienced along the Central and South American coasts (Fromard et al 1998; Nettel & Dodd 2007; Ram et al 2021), and because of their ability to be one of the first species to colonize newly formed mudflat areas (Toorman et al 2018; Triest et al 2021; Aye et al 2023). While there were a few R. mangle seedlings, no trees were present at the restored stands, possibly due to the saline conditions, different tidal inundation, low freshwater influence, and unfavorable topography (Duke & Allen 2006; Djamaluddin et al 2023).…”

Analysis of mangrove dynamics and its protection effect in the Guangdong-Hong Kong-Macao Coastal Area based on the Google Earth Engine platform

“…Hence, it is important to focus on the preservation of natural mangrove ecosystems. Besides, mangroves are a reservoir of both aboveground and belowground carbon, with a notable presence of belowground carbon (Djamaluddin et al, 2023). While replanted mangroves contribute to climate change mitigation, protecting the remaining natural mangroves is also valuable.…”