Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia

A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree planting.Tree diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal modes.We compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in Sumatra and Kalimantan(Indonesia)on mineral soils.Data on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same landscapes.Relatively undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species richness.Regulation-based logging had little impact on tree species richness.In rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 ha.The Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density profiles.Selectively logged forest managed by a local community(village forest)and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density trees.The majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all sites.Selectively logged forests had higher fractions of autochorous species(15%)compared to other sites.Anemochorous(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp forest.Comparison between secondary forests and agroforests showed the influence of farmer selection regarding what is allowed to grow beyond the pole stage.Wood density and seed dispersal profiles can be used as degradation indicators of species assemblages across various disturbance levels and types,as they reflect the habitat quality of the surrounding landscape mosaics.

Ranking Agricultural Sub-basins for Environmental Protection

Reconstructing long-term vegetation buffers along streams in agricultural landscapes has become a common environmental restoration strategy for improving water quality and wildlife habitat connectivity.This article developed a linear weighted model to rank the priority of agricultural sub-basins for the establishment of vegetative buffers.The method was applied to an agricultural watershed of 146 km2 in Ontario,Canada.The watershed was divided into 11 sub-basins as basic decision units.In each subbasin,four stream buffer schemes with widths of 5,10,15 and 20m were generated.For each buffer,three benefit-cost attributes of reconstructing vegetation cover were estimated,which include acreage per dollar,sediment abatement per dollar and habitat benefit per dollar.These attributes were first normalized using a linear normalization approach to eliminate the effects across different units.The normalized attributes were then integrated using a simple additive weighting method to rank the 11 sub-basins for prioritizing spatial restoration action.A sensitivity analysis was also conducted to observe the impact of a change in attribute weights on the management decisions.The results suggest that vegetation buffers reconstructed for achieving the water quality goal are not effective in improving habitat connectivity and vice versa.

Alleviating forest degradation in the Lancang-Mekong Region requires closing management—measurement gaps

Deforestation and forest degradation are having profound negative impacts on social-ecological systems in the emerging economies across the tropics.Consequently,interest in restoring and rehabilitating degraded forests has been growing.This paper explores current issues related to addressing forest degradation in the Lancang-Mekong Region(LMR)of Southeast Asia through a review of the use of criteria and indicators for forest degradation and rehabilitation.Forest degradation must be understood in the context of its underlying drivers,which are numerous and complex.Understanding these underlying drivers of degradation requires diagnosing the entwined political,social,economic,and environmental systems that aff ect forests.Landscapes are the relevant scales to diagnose and intervene for improved forests.Interventions to restore or rehabilitate forests should be process-driven,focused on the underlying social,ecological and political processes that degrade landscapes.Interventions should also include negotiation among all actors infl uencing and competing for natural resource claims in forest landscapes.Criteria and indicators for forest landscape restoration should therefore help to improve the governance of forest landscapes.Criteria and indicators provide measures of the biophysical outcomes of degradation,in addition to processes,but these should be adapted to changing contexts and emerging challenges,and should rectify any pre-existing fl awed change-logic.Restoration activities should synthesize,integrate,and build upon the rich history of pre-existing restoration guidelines,but should be adaptable in order to be applied eff ectively in the contexts of local landscapes.This project is facilitating a dialogue around the use of criteria and indicators to help solve the degradation challenge in the LMR.We will trial the use of the criteria and indicators generated through this research in the LMR to learn what works and what doesn’t.This will provide an opportunity to build consensus around the ways in which restoration investments made by governments,civil society,and the private sector can infl uence sustainability.

Comparative Study on Riparian Vegetation Buffers in Different Land Uses

This study focused on riparian vegetation buffer zones on the basis of low influence development(LID) and landscape restoration. Three types of land were selected to conduct comparative study. The types are buffers in urban districts,buffers in rural areas,and buffers in natural regions. These types basically reflect major ecological issues in different landuses. The follow conclusions were drawn:(1) there are different ecological issues in these 3 types,making the functions of buffers different.(2) The 3 types demand different ecological issues to be solved: Type A,functionally-diverse riparian landscape should be planned to enrich recreational activities and improve river's condition. Type B,agricultural areasource pollution needs to be cut down to sustain the stability of water conservation and ecological system. Type C,eco-conservation and various habitats for creatures are required.(3) Different planning methods were used respectively in the 3 types,construction methods were proposed for each type correspondingly and expressed in graphical ways in expectation of being instructive to the construction of eco-riparian landscape.