Ecotoxicological effects of commercial herbicides on the reproductive system of aquatic arthropod Limnocoris submontandoni (Hemiptera: Naucoridae)

Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects’ tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.

Woodlot management and livelihoods in a tropical conservation landscape

In biodiversity hotspots, there is often tension between human needs and conservation, exacerbated when protected areas prevent access to natural resources. Forest-dependent people may compensate for exclusion by managing unprotected forests or cultivating planted woodlots. Outside Bwindi Impenetrable National Park in Uganda, household wood product needs are high and population growth puts pressure on the environment. We investigated the role of privately and collectively managed woodlots in provisioning wood products and supporting local livelihoods. We found that households relied heavily on woodlots for daily needs and as resources during time of need. We also found that locally relevant social institutions, called stretcher groups, played a role in the management of woodlots, providing shared community resources. Privately and collectively owned woodlots support local livelihoods and wood product needs in the region. Long-term management of forests in Uganda should consider the value of woodlots and the mechanisms required to support them.

Playing Into the Hands of the Powerful: Extracting “Success” by Mining for Evidence in a Payments for Environmental Services Project in Matiguás-Río Blanco, Nicaragua

Payments for Environmental Services (PES) are premised upon the provision of monetary incentives to induce land-use practices viewed to be beneficial for advancing tropical conservation. A recent article published by Pagiola et al. in this journal claims that PES successfully transitioned land-use from agricultural use in Matiguás-Río Blanco, Nicaragua to silvopastoralism through afforestation and hence associated improvements in carbon sequestration and biodiversity conservation. Building on contrasting perspectives from peasants and local organizations in the region for more than a decade, we illustrate why viewing relations like payment provision and adoption of land-use outcomes that disregard parallel voices of implicated actors is not only analytically imprecise, but risks being anti-ecological if such a decontextualized connection is used to show evidence that tropical conservation is being advanced. We argue that the effect of payments must be contextualized with: a) increasingly globalized and expanding commodity frontiers for which PES programs may actually further advance to the detriment of tropical conservation; and b) the assumptions made in the methodological approaches adopted to determine causality. In sum, we highlight the dangers of uncritically portraying narratives of “success” to scale up investment to further proliferate decontextualized conservation projects that may not ensure long-term outcomes. We propose responding to these potential dangers through more open, horizontal, and long-term engagement on both the criteria and the consequences of defining success in tropical conservation interventions with actors whose lives are directly affected by them.