The potential ecological costs and cobenefits of REDD: a critical review and case study from the Amazon region

The United Nations climate treaty may soon include a mechanism for compensating tropical nations that succeed in reducing carbon emissions from deforestation and forest degradation, source of nearly one fifth of global carbon emissions. We review the potential for this mechanism [reducing emissions from deforestation and degradation (REDD)] to provoke ecological damages and promote ecological cobenefits. Nations could potentially participate in REDD by slowing clear‐cutting of mature tropical forest, slowing or decreasing the impact of selective logging, promoting forest regeneration and restoration, and expanding tree plantations. REDD could also foster efforts to reduce the incidence of forest fire. Potential ecological costs include the accelerated loss (through displaced agricultural expansion) of low‐biomass, high‐conservation‐value ecosystems, and substitution of low‐biomass vegetation by monoculture tree plantations. These costs could be avoided through measures that protect low‐biomass native ecosystems. Substantial ecological cobenefits should be conferred under most circumstances, and include the maintenance or restoration of (1) watershed functions, (2) local and regional climate regimes, (3) soils and biogeochemical processes, (4) water quality and aquatic habitat, and (5) terrestrial habitat. Some tools already being developed to monitor, report and verify (MRV) carbon emissions performance can also be used to measure other elements of ecosystem function, making development of MRV systems for ecological cobenefits a concrete possibility. Analysis of possible REDD program interventions in a large‐scale Amazon landscape indicates that even modest flows of forest carbon funding can provide substantial cobenefits for aquatic ecosystems, but that the functional integrity of the landscape's myriad small watersheds would be best protected under a more even spatial distribution of forests. Because of its focus on an ecosystem service with global benefits, REDD could access a large pool of global stakeholders willing to pay to maintain carbon in forests, thereby providing a potential cascade of ecosystem services to local stakeholders who would otherwise be unable to afford them.     

Fire Effects on Cover and Dietary Resources of Sage-Grouse Habitat

Abstract: We evaluated 6 years of vegetation response following prescribed fire in Wyoming big sagebrush (Artemisia tridentata spp. wyomingensis) steppe on vegetation cover, productivity, and nutritional quality of forbs preferred by greater sage-grouse (Centrocercus urophasianus), and abundance of common arthropod orders. Habitat cover (shrubs and tall herbaceous cover [>18 cm ht]) was about 50% lower after burning compared to unburned controls because of the loss of sagebrush. Perennial grasses and an invasive annual forb, pale alyssum (Alyssum alyssoides), increased in cover or yield after fire. There were no increases in yield or nutritional quality of forb species important in diets of sage-grouse. Abundance of ants (Hymenoptera), a significant component in the diet of young sage-grouse, decreased after fire. These results suggest that prescribed fire will not improve habitat characteristics for sage-grouse in Wyoming big sagebrush steppe where the community consists of shrubs, native grasses, and native forbs.     

The zoogeography, ecology and taxonomy of the genus Labeotropheus Ahl, 1927, of Lake Malawi (Pisces: Gichlidae)

Two species of Labeotropheus are currently recognized, but an earlier study of aquarium specimens caused doubt to be cast upon their specific distinctness. This doubt was removed by a field and laboratory study which showed that L. fuelleborni differed from L. trewavasae morphologically, in coloration, in geographic distribution, preferred habitat and ability to penetrate depth. The two species practise assortative mating.
Labeotropheus fuelleborni feeds predominantly from upper surfaces of rocks while L. trewavasae favours under surfaces. Although both species are specialized to crop epilithic algae they also feed secondarily on other food resources (e.g. plankton, insects) when these are available.
Gene flow between many populations of rock-frequenting cichlids is restricted by their sedentary nature and apparent inability to cross open water between rocky areas. Consequently, numerous geographic races, incipient species and species are found in the lake. This suggests that intralacustrine allopatric speciation may account for much of the species diversity of cichlids of rocky zones.
It is recommended that biologists working on cichlids from Lake Malawi should ascertain the precise location at which their specimens were caught and avoid using aquarium reared fish.     

Prevention of aluminium toxicity with supplemental boron. I. Maintenance of root elongation and cellular structure

Aluminium toxicity is an important factor limiting plant growth mi acid soils. Symptoms of B deficiency and Al toxicity are very similar and generally associated with impaired membrane Function and root growth. Thus the objective of this study was to determine whether supplemental B prevents Al inhibition of root growth and development. Squash (Cucurbita pepo L. cv. Sunbar) was grown in hydroponic nutrient media with 44 mmol m^?3 free Al and B concentrations extending from 5 to 100 mmol m^?3. Our results establish that B protects against Al inhibition of root growth. Protection was apparent at all levels of organization examined: primary root and lateral root lengths; primary root cell elongation, cell production rate, tissue organization and cell structure; primary root morphology and maturation. Protection against Al inhibition was also apparent for shoot growth. These studies were undertaken in solution culture to limit the variables examined; however, the underlying motivation for this study is the problem of worldwide Al toxicity in soils. Therefore, the effect of adding additional B to a high-Al soil was also investigated and is the subject of the companion paper (Le Noble. Blevins & Miles 1996, Plant, Cell and Environment 19, 1143–1148).     

Temperature-dependent variation in Anopheles merus larval head capsule width and adult wing length: implications for anopheline taxonomy

Abstract. Seasonal variations in mosquito larval head capsule width and adult female wing length were investigated in a field population of Anopheles merus Donitz at Nceswana Lake, Ophansi, within the endemic malaria area of Natal, South Africa. An inverse relationship was detected between each of these morphological characters and seasonal fluctuations in air/water temperatures. Mean head capsule width in all larval instars decreased by 4.8-7.9% in summer, while mean wing length decreased by 19.6%. These changes are discussed in relation to the annual range in mean air temperature in southern Africa and the distribution of An. merus. Implications for the use of such morphological characteristics in existing taxonomic keys are discussed.     

Subcellular Distribution of Enzymes in Ochromonas malhamensis*

SYNOPSIS. The activity and distribution of 7 enzymes in Ochromonas malhamensis were studied. Subcellular organelles were separated by centrifugation at 648,000 g min to precipitate the larger particles; the resulting supernatant was centrifuged at 5,560,000 g min to separate the microsomal fraction from the supernatant. Sixty-four percent of the cytochrome oxidase (1.9.3.1 ferrocytochrome c:oxygen oxidoreductase, 81% of the catalase (1.11.1.6 hydrogen-peroxide: hydrogen-peroxide oxidoreductase) and 70% of the urate oxidase (1.7.3.3 urate:oxygen oxidoreductase) activity was associated with the larger particles, altho only 20% of the total protein was found in this fraction. Three acid hydrolases, cathepsin (3.4.4.9 cathepsin C, acid phosphatase (3.1.3.2 orthophosphoric monoesterphosphohydrolase) and acid ribonuclease (2.7.7.17 ribonucleate nucleotido-2′-transferase) were found mostly in the supernate (50-60%, yet their latency and their similar subcellular distribution indicated the presence of lysosomes. After 2.5 hr centrifugation in a sucrose density gradient (ρ= 1.08–1.25, the acid hydrolases showed a broad distribution which differed greatly from cytochrome oxidase associated with mitochondria. Catalase, which could not be separated from cytochrome oxidase by centrifuging on this gradient, had a different distribution after centrifugation on a kinetic gradient. Urate oxidase had a similar distribution to catalase and both these enzymes were latent, indicating the presence of peroxisomes.     

Net woody vegetation increase confined to seasonally inundated lowlands in an Australian tropical savanna,Victoria River District,Northern Territory

Abstract Georeferenced digital aerial photographs were used to assess changes in overstorey vegetation cover since 1948 in the Victoria River District, Northern Territory, Australia, across a range of lowland tropical savanna habitats and with explicit consideration of known and variable site‐specific grazing and fire management histories. Vegetation surveys at corresponding locations on the ground identified five distinct woody vegetation communities defined primarily by water drainage and secondarily by soil characteristics. Air‐photo analyses revealed that, contrary to popular perceptions and in contrast to results from other habitats, there has been no generalized net increase in overstorey woody vegetation cover across the full range of lowland savanna habitats. Rather, different habitats exhibited distinctly different vegetation change mechanisms: low‐lying seasonally inundated ‘wet’ habitats have experienced woody vegetation increase since 1948, whereas well‐drained ‘dry’ habitats have experienced overstorey vegetation stability or loss. In almost every instance woody vegetation increase could be attributed to the invasion or proliferation of a single species, Melaleuca minutifolia F.Muell. The extent of M. minutifolia increase was unrelated to historical grazing/fire regime. Demographic analyses for this species revealed that recruitment was often episodic and that synchronized recruitment events occurred uniformly across the full range of historical management treatments, most likely as a consequence of favourable climatic conditions in years with an extended wet season. Heavy grazing facilitated juvenile survival and/or recruitment, most likely by reducing grassy fuel loads and eliminating landscape fire. We conclude that while there has been no generalized net increase in overstorey woody vegetation cover in lowland environments, savanna dynamics are complex, and multiple change mechanisms have occurred simultaneously in different habitats, some of which have been significantly transformed since 1948. Where net woody vegetation increase has occurred it is primarily a natural consequence of episodic M. minutifolia establishment in climatically favourable years, but the extent and magnitude of this effect is likely mediated by fire/grazing regime.