Incentive-Based Conservation Programs in Developing Countries: A Review of Some Key Issues and Suggestions for Improvements

Biodiversity conservation in developing countries has been a challenge because of the combination of rising human populations, rapid technological advances, severe social hardships, and extreme poverty. To address the social, economic, and ecological limitations of people-free parks and reserves, incentives have been incorporated into conservation programs in the hopes of making conservation meaningful to local people. However, such incentive-based programs have been implemented with little consideration for their ability to fulfill promises of greater protection of biodiversity. Evaluations of incentive-based conservation programs indicate that the approach continually falls short of the rhetoric. This article provides an overview of the problems associated with incentive-based conservation approaches in developing countries. It argues that existing incentive-based programs (IBPs) have yet to realize that benefits vary greatly at different “community” scales and that a holistic conceptualization of a community is essential to incorporate the complexities of a heterogeneous community when designing and implementing the IBPs. The spatial complexities involved in correctly identifying the beneficiaries in a community and the short-term focus of IBPs are two major challenges for sustaining conservation efforts. The article suggests improvements in three key areas: accurate identification of “target” beneficiaries, greater inclusion of marginal communities, and efforts to enhance community aptitudes.     

Assessing the Effects of Alternative Setback Channel Constraint Scenarios Employing a River Meander Migration Model

River channel migration and cutoff events within large river riparian corridors create heterogeneous and biologically diverse landscapes. However, channel stabilization (riprap and levees) impede the formation and maintenance of riparian areas. These impacts can be mitigated by setting channel constraints away from the channel. Using a meander migration model to measure land affected, we examined the relationship between setback distance and riparian and off-channel aquatic habitat formation on a 28-km reach of the Sacramento River, California, USA. We simulated 100 years of channel migration and cutoff events using 11 setback scenarios: 1 with existing riprap and 10 assuming setback constraints from about 0.5 to 4 bankfull channel widths (bankfull width: 235 m) from the channel. The percentage of land reworked by the river in 100 years relative to current (riprap) conditions ranged from 172% for the 100-m constraint setback scenario to 790% for the 800-m scenario. Three basic patterns occur as the setback distance increases due to different migration and cutoff dynamics: complete restriction of cutoffs, partial restriction of cutoffs, and no restriction of cutoffs. Complete cutoff restriction occurred at distances less than about one bankfull channel width (235 m), and no cutoff restriction occurred at distances greater than about three bankfull widths (∼700 m). Managing for point bars alone allows the setbacks to be narrower than managing for cutoffs and aquatic habitat. Results suggest that site-specific “restriction of cutoff” thresholds can be identified to optimize habitat benefits versus cost of acquired land along rivers affected by migration processes.     

Incompatible Land Uses and the Topology of Cumulative Risk

The extensive literature on environmental justice has, by now, well defined the essential ingredients of cumulative risk, namely, incompatible land uses and vulnerability. Most problematic is the case when risk is produced by a large aggregation of small sources of air toxics. In this article, we test these notions in an area of Southern California, Southeast Los Angeles (SELA), which has come to be known as Asthmatown. Developing a rapid risk mapping protocol, we scan the neighborhood for small potential sources of air toxics and find, literally, hundreds of small point sources within a 2-mile radius, interspersed with residences. We also map the estimated cancer risks and noncancer hazard indices across the landscape. We find that, indeed, such large aggregations of even small, nondominant sources of air toxics can produce markedly elevated levels of risk. In this study, the risk profiles show additional cancer risks of up to 800 in a million and noncancer hazard indices of up to 200 in SELA due to the agglomeration of small point sources. This is significant (for example, estimates of the average regional point-source-related cancer risk range from 125 to 200 in a million). Most importantly, if we were to talk about the risk contour as if they were geological structures, we would observe not only a handful of distinct peaks, but a general “mountain range” running all throughout the study area, which underscores the ubiquity of risk in SELA. Just as cumulative risk has deeply embedded itself into the fabric of the place, so, too, must intervention seek to embed strategies into the institutions and practices of SELA. This has implications for advocacy, as seen in a recently initiated participatory action research project aimed at building health research capacities into the community in keeping with an ethic of care.     

micro-XANES and micro-XRF investigations of metal binding mechanisms in biosolids

Micro-X-ray fluorescence (micro-XRF) microprobe analysis and micro-X-ray absorption near-edge structure (micro-XANES) spectroscopy were employed to identify Fe and Mn phases and their association with selected metals in two biosolids (limed composted [LC] and Nu-Earth) before and after treatment to remove organic carbon (OC). Spatial correlations derived from elemental mapping of XRF images showed strong correlations between Fe and Cd, Cr, Pb, or Zn (r2= 0.65-0.92) before and after removal of most of the OC. The strong correlation between Fe and Cu that was present in intact samples disappeared after OC removal, suggesting that Cu was associated with OC coatings that may have been present on Fe compounds. Except for Fe and Cr, the spatial correlations of metals with Mn were improved after treatment to remove OC, indicating that the treatment may have altered more than the OC in the system. The Fe micro-XANES spectra of the intact biosolids sample showed that every point had varying mixtures of Fe(II and III) species and no two points were identical. The lack of uniformity in Fe species in the biosolids sample illustrates the complexity of the materials and the difficulty of studying biosolids using conventional analytical tools or chemical extraction techniques. Still, these microscopic observations provide independent information supporting the previous laboratory and field hypothesis that Fe compounds play a major role in retention of environmentally important trace elements in biosolids. This could be due to co-precipitation of the metals with Fe, adsorption of metals by Fe compounds, or a combination of both mechanisms.     

Nitrogen and phosphorus leaching from growing season versus year-round application of wastewater on seasonally frozen lands

Land application of wastewater has become an important disposal option for food-processing plants operating year-round. However, there are concerns about nutrient leaching from winter wastewater application on frozen soils. In this study, P and N leaching were compared between nongrowing season application of tertiary-treated wastewater plus growing season application of partially treated wastewater (NGS) vs. growing season application of partially treated wastewater (GS) containing high levels of soil P. As required by the Minnesota Pollution Control Agency (MPCA), the wastewater applied to the NGS fields during October through March was treated such that it contained < or =6 mg L(-1) total phosphorus (TP), < or =10 mg L(-1) NO3-N, and < or =20 mg L(-1) total Kjeldahl nitrogen (TKN). The only regulation for wastewater application during the growing season (April through September) was that cumulatively it did not exceed the agronomic N requirements of the crop in any sprayfield. Application of tertiary-treated wastewater during the nongrowing season plus partially treated wastewater during the growing season did not significantly increase NO3-N leaching compared with growing season application of nonregulated wastewater. However, median TP concentration in leachate was significantly higher from the NGS (3.56 mg L(-1)) than from the GS sprayfields (0.52 mg L(-1)) or nonirrigated sites (0.52 mg L(-1)). Median TP leaching loss was also significantly higher from the NGS sprayfields (57 kg ha(-1)) than from the GS (7.4 kg ha(-1)) or control sites (6.9 kg ha(-1)). This was mainly due to higher hydraulic loading from winter wastewater application and limited or no crop P uptake during winter. Results from this study indicate that winter application of even low P potato-processing wastewater to high P soils can accelerate P leaching. We conclude that the regulation of winter wastewater application on frozen soils should be based on wastewater P concentration and permissible loading. We also recommend that winter irrigation should take soil P saturation into consideration.     

Nitrogen and phosphorus status of soils and trophic state of lakes associated with forage-based beef cattle operations in Florida

Forage-based livestock systems have been implicated as major contributors to deteriorating water quality, particularly for phosphorus (P) from commercial fertilizers and manures affecting surface and ground water quality. Little information exists regarding possible magnitudes of nutrient losses from pastures that are managed for both grazing and hay production and how these might impact adjacent bodies of water. We examined the changes that have occurred in soil fertility levels of rhizoma peanut (Arachis glabrata Benth.)-based beef cattle pastures (n = 4) in Florida from 1988 to 2002. These pastures were managed for grazing in spring followed by haying in late summer and were fertilized annually with P (39 kg P2O5 ha(-1)) and K (68 kg K2O ha(-1)). Additionally, we investigated trends in water quality parameters and trophic state index (TSI) of lakes (n = 3) associated with beef cattle operations from 1993 to 2002. Overall, there was no spatial or temporal buildup of soil P and other crop nutrients despite the annual application of fertilizers and daily in-field loading of animal waste. In fact, soil fertility levels showed a declining trend for crop nutrient levels, especially soil P (y = 146.57 - 8.14 x year; r2= 0.75), even though the fields had a history of P fertilization and the cattle were rotated into the legume fields. Our results indicate that when nutrients are not applied in excess, cow-calf systems are slight exporters of P, K, Ca, and Mg through removal of cut hay. Water quality in lakes associated with cattle production was "good" (30-46 TSI) based on the Florida Water Quality Standard. These findings indicate that properly managed livestock operations may not be major contributors to excess loads of nutrients (especially P) in surface water.     

Phosphorus sequestration by chemical amendments to reduce leaching from wastewater applications

Phosphorus-immobilizing amendments can be useful in minimizing P leaching from high P soils that may be irrigated with wastewater. This study tested the P-binding ability of various amendment materials in a laboratory incubation experiment and then tested the best amendment in a field setup using drainage lysimeters. The laboratory experiment involved incubating 100-g samples of soil (72 mg kg(-1) water-extractable phosphorus, WEP) with various amendments at different rates for 63 d at field moisture capacity and 25 degrees C. The amendments tested were alum [Al2SO4)3.14H2O], ferric chloride (FeCl3), calcium carbonate (CaCO3), water treatment residual (WTR), and sugarbeet lime (SBL). Ferric chloride and alum at rates of 1.5 and 3.9 g kg(-1), respectively, were the most effective amendments that decreased WEP to 20 mg kg(-1), below which leaching has previously been shown to be low. Alum (1.3 kg m(-2)), which is less sensitive to redox conditions, was subsequently tested under field conditions, where it reduced WEP concentration in the 0- to 0.15-m layer from 119 mg kg(-1) on Day 0 to 36.1 mg kg(-1) (85% decrease) on Day 41. Lysimeter breakthrough tests using tertiary-treated potato-processing wastewater (mean total phosphorus [TP] = 3.4 mg L(-1)) showed that alum application reduced leachate TP and soluble reactive phosphorus (SRP) concentrations by 27 and 25%, respectively. These results indicate that alum application may be an effective strategy to immobilize P in high P coarse-textured soils. The relatively smaller decreases in TP and SRP in the leachate compared to WEP suggest some of the P may be coming from depths below 0.2 m. Thus, to achieve higher P sequestration, deeper incorporation of the alum may be necessary.     

Carbon and nitrogen mineralization rates after application of organic amendments to soil

The objective of this study was to quantify C and N mineralization rates from a range of organic amendments that differed in their total C and N contents and C quality, to gain a better understanding of their influence on the soil N cycle. A pelletized poultry manure (PP), two green waste-based composts (GWCa, GWCb), a straw-based compost (SBC), and a vermi-cast (VER) were incubated in a coarse-textured soil at 15 degrees C for 142 d. The C quality of each amendment was determined by chemical analysis and by 13C nuclear magnetic resonance (NMR). Carbon dioxide (CO2-C) evolution was determined using alkali traps. Gross N mineralization rates were calculated by 15N isotopic pool dilution. The CO2-C evolution rates and gross N mineralization rates were generally higher in amended soils than in the control soil. With the exception of GWCb all amendments released inorganic N at concentrations that would be high enough to warrant a reduction in inorganic N fertilizer application rates. The amount of N released from PP was high indicating that application rates should be reduced, or alternative amendments used, to minimize leaching losses in regions where ground water quality is of concern. There was a highly significant relationship between CO2-C evolution and gross N mineralization (R2= 0.95). Some of the chemically determined C quality parameters had significant relationships (p < 0.05) with both the cumulative amounts of C and N evolved. However, we found no significant relationships between 13C NMR spectral groupings, or their ratios, and either the CO2-C evolved or gross N mineralized from the amendments.     

Bedding and within-pen location effects on feedlot pen runoff quality using a rainfall simulator

Soluble salts, nutrients, and pathogenic bacteria in feedlot-pen runoff have the potential to cause pollution of the environment. A 2-yr study (1998-1999) was conducted at a beef cattle (Bos taurus) feedlot in southern Alberta, Canada, to determine the effect of bedding material [barley (Hordeum vulgare L.) straw versus wood chips] and within-pen location on the chemical and bacterial properties of pen-floor runoff. Runoff was generated with a portable rainfall simulator and analyzed for chemical content (nitrogen [N], phosphorus [P], soluble salts, electrical conductivity [EC], sodium adsorption ratio [SAR], dissolved oxygen [DO], and pH) and populations of three groups of bacteria (Escherichia coli, total coliforms, total aerobic heterotrophs at 27 degrees C) in 1998 and 1999. Bedding had a significant (P < or = 0.05) effect on NH4-N concentration and load in 1999, SO4 load in 1998, SO4 concentration and load in 1999, and total coliforms in both years; where these three variables were higher in wood than straw pens. Location had a significant effect on EC and concentrations of total Kjeldahl nitrogen (TKN), Na, K, SO4, and Cl in 1998, and total coliforms in both years. These seven variables were higher at the bedding pack than pen floor location, indicating that bedding packs were major reservoirs of TKN, soluble salts, and total coliforms. Significantly higher dissolved reactive phosphorus (DRP), total P, and NH4-N concentrations and loads at the bedding pack location in wood pens in 1998, and a similar trend for TKN concentration in 1999, indicated that this bedding-location treatment was a greater source of nutrients to runoff than the other three bedding-location treatments. Bedding, location, and their interaction may therefore be a potential tool to manage nutrients, soluble salts, and bacteria in feedlot runoff.