No abstract

Surface gold mining severely degrades landscapes, causing deforestation, soil erosion and displacement, and toxic contamination. The prevalence of both large-scale and artisanal, small-scale surface gold mining in the tropics has risen over recent decades.Restoration strategies developed for less-severe forms of degradation may not sufficiently address the unique ecological conditions of former gold mines. In this review, we summarize biophysical challenges to the restoration and reforestation of largeand small-scale gold mines in the tropics and synthesize the findings of studies that test restoration strategies at these sites. Certain practices, such as the backfilling of mined pits, topsoil conservation, and the preservation of local seed sources, emerge from the literature as crucial for the timely and effective restoration of gold mines.However, because the severity of ecological degradation varies greatly within and between individual mines, and given the relatively small number (n = 42) of published tropical field studies found in our literature review, we highlight a clear need for continued research and development of restoration strategies specific to ecological conditions of former gold mines in the tropics.

Land degradation in Borneo, one of the world's richest biodiversity hotspots, is extensive. In East Kalimantan, 5,000,000 ha of land are zoned for surface-mined coal.Deforestation from this mining threatens biodiversity and results in soil degradation, erosion, and polluted runoff, all directly impacting human populations. Revegetation methods developed for temperate forests are commonly used globally for mine rehabilitation. However, few empirical studies of native forest restoration as part of mine rehabilitation exist from wet tropical regions. Here, a chronosequence was established to observe forest succession under leguminous plantations at the PT Singlurus Pratama coal mine in East Kalimantan, Indonesia. Soil and natural regeneration data were recorded from samples of ten 20 × 60-m plots randomly located in plantings aged 2, 7, and, 9 years postmining. Linear models (LMEMs) did not reveal greater soil pH, woody plant diversity, or soil phosphorus and nitrogen in older plantings. Rather, they showed higher soil carbon in older plantings, whereas nitrogen and pH were positively correlated with woody species diversity and abundance.Graminoids were less abundant, but ferns were more abundant in older sites in an ordination analysis. The implications are exotic tree plantations shade-out competitive understory herbaceous species (such as graminoids), opening growing space for other vegetation. However, the establishment of woody species is spatially limited possibly by differences in soil degradation among sites. Our results suggest that planting leguminous trees alone may not be sufficient to restore native forests, and future management should conserve and facilitate the establishment of tropical forest topsoil.

The goal of a day-long symposium on March 3, 2015, Sturgeon in the Sacramento-San Joaquin Watershed: New Insights to Support Conservation and Management, was to present new information about the physiology, behavior, and ecology of the green (Acipenser medirostris) and white sturgeon (Acipenser transmontanus) to help guide enhanced management and conservation efforts within the Sacramento-San Joaquin watershed. This symposium identified current unknowns and highlighted new electronic tracking technologies and physiological techniques to address these knowledge gaps. A number of presentations, each reviewing ongoing research on the two species, was followed by a round-table discussion, in which each of the participants was asked to share recommendations for future research on sturgeon in the watershed. This article presents an in-depth review of the scientific information presented at the symposium with a summary of recommendations for future research.

The effects of anomalous oceanographic conditions on growth, abundance, spawn-date distributions, and diet of early-juvenile Pacific hake Merluccius productus were examined in nursery grounds off the coast of central California, USA. Spring collections from 2 consecutive years of El