Socioeconomic outcomes of agricultural land use change in Southeast Asia

Agricultural land use is transforming rapidly in Southeast Asia, often supported by development policies aiming primarily at economic growth. However, the socioeconomic outcomes of these changes for smallholder farmers remain unclear. Here, we systematically review cases of agricultural land use change in Southeast Asia to assess their socioeconomic outcomes and potential trade-off and synergies in these outcomes. Of the 126 reviewed cases, we find mostly positive outcomes for income (SDG 1, 100 cases) and employment (SDG 8, 11 cases), while outcomes on health (SDG 3, 9 cases) were mixed, and outcomes for food security (SDG 2, 44 cases), gender equality (SDG 5, 13 cases), and economic equality (SDG 10, 14 cases) were mostly negative. Studies describing multiple outcomes show indications of synergies between income and food security, and between income and employment, but also potential trade-offs between income and economic equality. In addition, we find that economic land concessions result in multiple negative outcomes more often than other types of land governance regimes. The results provide evidence that economic gains from agricultural land use change often come at a cost of other dimensions of sustainable development.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01712-4.     

Use of two-surfactants mixtures to attain specific HLB values for assisted TPH-diesel biodegradation

In a surfactant assisted biodegradation process, the choice of surfactant(s) is of crucial importance. The question is: does the type of surfactant(i, e. chemical family) affect the biodegradation process at fixed hidrophillic-lypofillic balance(H/B) values? Microcosm assessments were developed using contaminated soil, with around of 5000 mg/kg of hydrocarbons as TPH-diesel. Mixtures of three nonionic surfactants were employed to get a wide range of specific HLB values. Tween20 and Span20 were mixed in the appropriate proportions to get HLB values between 8.6 and 16.7. Tween/Span60 mixtures reached HLB values between 4.7 and 14.9. Finally,Tween/Span80 combinations yielded HLB values between 4.3 and 1.5. TPH-diesel biodegradation was measured at the beginning, and after 8 weeks, as well as the FCU/grsod, as a measure of microorganisms‘ development during the biodegradation period. A second aim of this work was to assess the use of guar gum as a biodegradation enhancer instead of synthetic products. The conclusions of this work are that surfactant chemical family, and not only the HLB value clearly affects the assisted biodegradation rate. Surfactant‘s synergism was clearly observed. Regarding the use of guar gum, no biodegradation enhancement was observed for the three assessed concentrations,i.e., 2, 20, and 200 mg/kg, respectively. On the contrary, TPH-diesel removal was lower as the gum concentration increased. It is quite possible that guar gum was used as a microbial substrate.     

Influence of Mining Activities in the North of Potosi, Bolivia on the Water Quality of the Chayanta River, and its Consequences

Mining activity in the North of Potosi (Siglo XX mine, Ingenio Catavi-Siglo XX, Pucro mine and Colquechaca mine) produces minewater containing high concentrations of heavy metals such as As (0.02-34 mg/l), Cd (45-11,600 microg/l), Cu (0.35-32 mg/l), Fe (42-1,010 mg/l), Pb(33-3,130 microg/l), Ni(20-4,320 microg/l), and Zn (1.1-485 mg/l), that exceed considerably the limit values. The rivers in the North of Potosi (Katiri and Pongoma) that do not receive minewater contain clear water with rather low heavy metal concentrations. These rivers and also other rivers contaminated with minewater, are tributaries of the Chayanta River that transports water with a high concentration of heavy metals such as As (6-24 microg/l), Cd (260-2,620 microg/l), Cu (205-812 microg/l), Pb(10-21 microg/l) and Ni(110-332 microg/l). These elements result from mining activity, as indicated by a comparison with rivers not contaminated by minewater discharges. Water of the Chayanta River, used all year long by the population of Quila Quila, (a village situated at about 75 km from the mining centers), for the irrigation of crops such as potato, maize and broad bean, contains heavy metal concentrations exceeding for several elements the guidelines for irrigation. As drinking water the population of Quila Quila consumes spring water with a generally acceptable heavy metal concentration, as well as infiltrated water of Chayanta River (which is also used in animal drinking troughs) with a high concentration of Cd (23-63 microg/l), exceeding the limit value for drinking water. The metal concentration is significantly lower in the infiltrated water than in the water of Chayanta River. Some technological solutions are suggested to improve the quality of the water used. Surveys carried out on inhabitants of the region, showed that many people present health problems, probably to be attributed to the bad quality of the water they consume and use for irrigation.     

Emergency drills for agricultural drought response: a case study in Guatemala

Drills are an important element of disaster management, helping to increase preparedness and reduce the risk of real‐time failure. Yet, they are not applied systematically to slow‐onset disasters such as a drought, which causes damage that is not instantly apparent and thus does not solicit immediate action. This case study evaluates how drills inform institutional responses to slow‐onset disasters. It spotlights Guatemala, a country where drought has severe impacts on livelihoods and the food security of small farmers. By implementing part of the Ministry of Agriculture, Livestock and Food's institutional response plan for drought, it explores how drills can help to detect issues in emergency response and to foster an institutional focus on improvements in preparedness. The results reveal that drills alone do not trigger institutional improvements if unsupported by a wider strategy that seeks to enhance capacities and protocols. These findings are valuable, however, in making problems transparent and in creating the space for discussion.     

Evolution and decay of gravity wavefields in weak-rotating environments: a laboratory study

Gravity waves are prominent physical features that play a fundamental role in transport processes of stratified aquatic ecosystems. In a two-layer stratified basin, the equations of motion for the first vertical mode are equivalent to the linearised shallow water equations for a homogeneous fluid. We adopted this framework to examine the spatiotemporal structure of gravity wavefields weakly affected by the background rotation of a single-layer system of equivalent thickness \(h_{\ell }\), via laboratory experiments performed in a cylindrical basin mounted on a turntable. The wavefield was generated by the release of a diametral linear tilt of the air–water interface, \(\eta _{\ell }\), inducing a basin-scale perturbation that evolved in response to the horizontal pressure gradient and the rotation-induced acceleration. The basin-scale wave response was controlled by an initial perturbation parameter, \({\mathcal{A}}_{*} = \eta _{0}/h_{\ell }\), where \(\eta _{0}\) was the initial displacement of the air–water interface, and by the strength of the background rotation controlled by the Burger number, \({\mathcal{S}}\). We set the experiments to explore a transitional regime from moderate- to weak-rotational environments, \(0.65\le {\mathcal{S}} \le 2\), for a wide range of initial perturbations, \(0.05\le {\mathcal{A}}_{*}\le 1.0\). The evolution of \(\eta _{\ell }\) was registered over a diametral plane by recording a laser-induced optical fluorescence sheet and using a capacitive sensor located near the lateral boundary. The evolution of the gravity wavefields showed substantial variability as a function of the rotational regimes and the radial position. The results demonstrate that the strength of rotation and nonlinearities control the bulk decay rate of the basin-scale gravity waves. The ratio between the experimentally estimated damping timescale, \(T_{d}\), and the seiche period of the basin, \(T_{g}\), has a median value of \(T_{d}/T_{g}\approx 11\), a maximum value of \(T_{d}/T_{g}\approx 10^{3}\) and a minimum value of \(T_{d}/T_{g}\approx 5\). The results of this study are significant for the understanding the dynamics of gravity waves in waterbodies weakly affected by Coriolis acceleration, such as mid- to small-size lakes.     

Field Exposure Study of Polylactic Acid (PLA) Plastic Films in the Banana Fields of Costa Rica

For use by the banana industry of Costa Rica, polylactic acid (PLA) plastic ropes and banana finger shrouds must remain operational for 14 to 16 weeks, and they also must be able to break down in the soil after serving their purposes. The banana field at La Rebusca Farm (Costa Rica) and the experiment station at University of Costa Rica were selected for a field exposure study of Cargill EcoPla Generation II (GII) and Cargill EcoPla monolayer (Ca-I) PLA films. The average monthly temperature, relative humidity, and cumulative rainfall of the La Rebusca Farm and the University of Costa Rica site were 26 and 22°C, 92 and 84%, and 352 and 177 in., respectively. The PLA plastic films at the La Rebusca Farm lost their mechanical properties earlier than at the University of Costa Rica site because of the higher temperature and relative humidity of the banana farm. The Ca-I film meets the 14-week operational time frame and it is recommended for further studies as ropes and banana shrouds.     

Transbranchial potentials and ion fluxes across isolated,perfused gills of Uca rapax

Transbranchial potentials (TP) and sodium or chloride fluxes were measured in an apparatus designed for the simultaneous perfusion of eight isolated gills of Uca rapax. In anterior gills perfused with U. rapax–saline (US) the TP varied almost linearly from-7.5 to +10 mV inside, and in posterior gills from +2 to-8.5 mV (inside), on exposure to salinities ranging from 8.7 through 52, i.e. 25 to 150% seawater (100%=34.6 S). Sodium influx and efflux in anterior gills exposed to US, 8.7 or 43.3 S (0.7 to 4.0 mmol h^–1 g^–1 dry wt) were always greater than in posterior gills (0.5 mmol h^–1). The chloride fluxes were slightly smaller than sodium fluxes in anterior gills, while in the posterior gills the chloride influx (2.8 to 4.6 mmol h^–1) was always larger than chloride efflux (0.6 to 1.1 mmol h^–1) or the sodium fluxes. At least three ion-transport mechanisms may be present in these gills: (1) an internal ( = basolateral), ouabain-sensitive Na⁺, K⁺ pump, restricted to anterior gills; (2) a furosemide-sensitive Na⁺, K⁺, 2Cl^– (plus water) transporter, apparently restricted to posterior gills, and (3) a Na⁺ exchanger (and possibly other as yet unidentified ion transporters, as suggested by large increases of the chloride influxes caused by amiloride), probably located on the apical membranes of the epithelial cells of both gill types. The differential selectivity of the gills of U. rapax for sodium or chloride may limit the transbranchial movements of either ion, without a reduction of the overall permeability of these crabs.Communicated by N.H. Marcus, Tallahassee     

Local initiatives and adaptation to climate change

Climate change is expected to lead to an increase in the number and strength of natural hazards produced by climatic events. This paper presents some examples of the experiences of community-based organisations (CBOs) and non-governmental organisations (NGOs) of variations in climate, and looks at how they have incorporated their findings into the design and implementation of local adaptation strategies. Local organisations integrate climate change and climatic hazards into the design and development of their projects as a means of adapting to their new climatic situation. Projects designed to boost the resilience of local livelihoods are good examples of local adaptation strategies. To upscale these adaptation initiatives, there is a need to improve information exchange between CBOs, NGOs and academia. Moreover, there is a need to bridge the gap between scientific and local knowledge in order to create projects capable of withstanding stronger natural hazards.