Cultivation and Conservation in Ngorongoro Conservation Area, Tanzania

Ngorongoro Conservation Area (NCA), Tanzania, contains renowned wildlife, an expanding human population, and cultivation by Maasai agro-pastoralists and non-Maasai agriculturalists. We used integrated assessments to explore some effects of cultivation on livestock, resident wildlife, and people. Using a Landsat image from 2000, we mapped 3,967 ha [9,803 acres (ac)] of cultivation within NCA, or 39.7 km² of the 8,283 km² conservation area. Using integrative ecosystem (Savanna) and household (PHEWS) models, we assessed effects of: up to 50,000 ac (20,234 ha) of cultivation; cultivation concentrated into two blocks totaling 10,000 ac (4,047 ha) and 20,000 ac (8,094 ha) that may be more palatable to tourists; and human population growth. Simulations with from 10,000 to 50,000 ac in cultivation showed no large changes in ungulate populations relative to there being no cultivation. When cultivation was altered to be in two blocks, some wildlife populations changed (≤15%) and ungulate biomass remained the same. When cultivation was increased linearly with human population, poor households needed 25% of their diets to come from relief as populations tripled, because livestock could not increase significantly. Our results indicate that having <1% of NCA in cultivation, in its current distribution, is not overly detrimental to wildlife or livestock populations, and is important to Maasai well-being.     

Addressing management questions for Ngorongoro Conservation Area, Tanzania, using the Savanna modelling system

Ngorongoro Conservation Area (NCA), in northern Tanzania, is a multiple-use area of importance to Maasai pastoralists and wildlife conservation. We adapted the Savanna modelling system to the NCA, creating an Integrated Management and Assessment System that allows users to assess responses to alternative management actions. We used the system to conduct fifteen experiments reflecting potential management questions. Results suggest that: the distribution of rainfall throughout the year may have a greater impact on the ecosystem than its quantity; cattle may be near a carrying capacity determined not by forage limitations but because of disease risks; increasing survival and reducing disease in livestock yields greater returns than increasing birth rates; allowing livestock to graze in areas where they are currently excluded may lead to a slight increase in livestock populations, but sometimes leads to large declines in wildlife populations; few ecosystem effects were noted when households and cultivation were allowed to grow at 3% per year for 15 years; and when up to 5% of the study area was in cultivation, there were declines ≤16% in livestock and wildlife populations, except for elephants, which declined by 48%. Users may modify our experiments using tools we have developed, or address other NCA management questions.     

Geophagy and nutrient supplementation in the Ngorongoro Conservation Area, Tanzania, with particular reference to selenium, cobalt and molybdenum

Wildlife and livestock in the Ngorongoro Conservation Area (NCA), Tanzania, commonly practise geophagy. We investigated the nutrient content of nine earth licks and adjacent topsoils in the NCA, and for comparative purposes, two salt pans in north-eastern Tanzania, licks in central Tanzania and a lick near Puerto Maldonado, Peru. The licks had no consistent pattern of nutrient enrichment relative to unutilized topsoils, although the Na content of licks was greater than that of the adjacent topsoils at all but one site. The three largest licks in the NCA (Gibbs Farm, Seneto and Ascent Road) were enriched relative to topsoils and global averages in Se (maximum of 4.7 mg kg⁻¹), Co (maximum of 107 mg kg⁻¹) and/or Mo (maximum of 7.4 mg kg⁻¹). We suggest that licks do provide supplemental Na, but that Se, Co and/or Mo at the largest licks provide easily overlooked nutritional benefits and are perhaps the primary target for geophagy at these sites. Subsoil zones of clay deposition are likely to be enriched in various elements through illuviation or mineral precipitation from solution. Animals may use the taste of NaCl as a clue for locating such zones where they are likely to find a greater quantity of micronutrients relative to other soils. These findings have consequences for conservation and pastoralism in that these large licks may be key resources, providing micronutrients that are essential for maintaining the health and fecundity of animal as well as human populations in the region.     

Habitat conservation prioritization: A floristic approach applied to a Mediterranean wetland network

The importance of plant communities for conservation purposes is recognized in their inclusion in the “Habitat Directive” (92/43 EEC), that relates habitat types to plant community syntaxonomic units. However, habitat definitions in the Habitat Directive lead to several inaccuracies in local habitat characterization. Several wetland plant communities (and their corresponding habitats), rare in the Mediterranean basin, are not included in the Habitat Directive. This study proposes criteria for assessing the conservation importance of habitats. It deals with plant community types at the alliance level, as promising units for setting conservation priorities. The principle criteria considered as drivers for setting alliance conservation values are the distribution and abundance of plant species of conservation interest and their fidelity to a plant community. Multivariate methods were used, and a quantitative floristic index of alliance conservation priority was created. This procedure was applied to an important wetland in central Italy. Results emphasize: (i) high conservation values of some alliances not listed in the Habitat Directive, confirming various gaps in the current conservation law affecting Mediterranean wetlands; (ii) that habitats widely distributed in other biogeographical areas, may greatly underestimate their conservation importance in Mediterranean region; (iii) need to consider regional peculiarities when setting conservation priorities.     

A landscape approach to conservation of birds

Landscape ecology as a discipline in science is rather young. However its principles appear promising in outlining conservation strategies including a wide range of organisms, particularly birds. Birds due to their mobility use a variety of environmental resources, especially habitats. However, currently these habitats are only available in patches over most of the tropical world. Further whatever is left is under constant human pressure. This paper, therefore, addresses this problem and suggests means of dealing with it using the landscape approach as outlined by landscape ecology. The landscape approach starts with the realization that patches of habitats are open and interact with one another. Corridors of trees along roads, hedgerows and canals in a landscape can aid in the movement of species. Hence the landscape approach considers patches of habitats as interacting elements in the large matrix of the landscape. The landscape approach also integrates concepts. It puts together often debated issues such as whether to preserve maximum species diversity, to maximize representativeness, or to preserve only the valuable species. Based on a case study of the Uttara Kannada district in Karnataka, these oft-opposing views and complications can be dealt with practically and synthesized into a conservation strategy for the diverse avifauna of the Western Ghats.     

Use and conservation of woody vegetation by the Batemi of Ngorongoro District,Tanzania

The Batemi, agropastoralists of north-central Tanzania, inhabit a landscape of savanna and scrub woodland. We identified 61 species of woody plants used by the Batemi for 19 types of items. The reports indicated 39 species are used for construction, 19 species for cultural artifacts, 23 for firewood and 6 live trees for fences, boundaries and shade. The Batemi have extensive knowledge of species habitat and distinctive management strategies for woody vegetation, particularly for the well-forested irrigation channels and spring sources. To date, a total of 90 species of woody plants have been identified as useful to the Batemi. Compared to the total number of species found within the study area, the Batemi use 79% of woody plant species in the area.     

A systems biology approach to learning autophagy

With its relevance to our understanding of eukaryotic cell function in the normal and disease state, autophagy is an important topic in modern cell biology; yet, few textbooks discuss autophagy beyond a two- or three-sentence summary. Here, we report an undergraduate/graduate class lesson for the in-depth presentation of autophagy using an active learning approach. By our method, students will work in small groups to solve problems and interpret an actual data set describing genes involved in autophagy. The problem-solving exercises and data set analysis will instill within the students a much greater understanding of the autophagy pathway than can be achieved by simple rote memorization of lecture materials; furthermore, the students will gain a general appreciation of the process by which data are interpreted and eventually formed into an understanding of a given pathway. As the data sets used in these class lessons are largely genomic and complementary in content, students will also understand first-hand the advantage of an integrative or systems biology study: No single data set can be used to define the pathway in full-the information from multiple complementary studies must be integrated in order to recapitulate our present understanding of the pathways mediating autophagy. In total, our teaching methodology offers an effective presentation of autophagy as well as a general template for the discussion of nearly any signaling pathway within the eukaryotic kingdom.     

A climatic stability approach to prioritizing global conservation investments

Climate change is impacting species and ecosystems globally. Many existing templates to identify the most important areas to conserve terrestrial biodiversity at the global scale neglect the future impacts of climate change. Unstable climatic conditions are predicted to undermine conservation investments in the future. This paper presents an approach to developing a resource allocation algorithm for conservation investment that incorporates the ecological stability of ecoregions under climate change. We discover that allocating funds in this way changes the optimal schedule of global investments both spatially and temporally. This allocation reduces the biodiversity loss of terrestrial endemic species from protected areas due to climate change by 22% for the period of 2002-2052, when compared to allocations that do not consider climate change. To maximize the resilience of global biodiversity to climate change we recommend that funding be increased in ecoregions located in the tropics and/or mid-elevation habitats, where climatic conditions are predicted to remain relatively stable. Accounting for the ecological stability of ecoregions provides a realistic approach to incorporating climate change into global conservation planning, with potential to save more species from extinction in the long term.     

A Bayesian approach to the evolution of social learning

There has been much interest in understanding the evolution of social learning. Investigators have tried to understand when natural selection will favor individuals who imitate others, how imitators should deal with the fact that available models may exhibit different behaviors, and how social and individual learning should interact. In all of this work, social learning and individual learning have been treated as alternative, conceptually distinct processes. Here we present a Bayesian model in which both individual and social learning arise from a single inferential process. Individuals use Bayesian inference to combine social and nonsocial cues about the current state of the environment. This model indicates that natural selection favors individuals who place heavy weight on social cues when the environment changes slowly or when its state cannot be well predicted using nonsocial cues. It also indicates that a conformist bias should be a universal aspect of social learning.     

A network medicine approach to human disease

High-throughput interaction discovery initiatives are providing thousands of novel protein interactions which are unveiling many unexpected links between apparently unrelated biological processes. In particular, analyses of the first draft human interactomes highlight a strong association between protein network connectivity and disease. Indeed, recent exciting studies have exploited the information contained within protein networks to disclose some of the molecular mechanisms underlying complex pathological processes. These findings suggest that both protein-protein interactions and the networks themselves could emerge as a new class of targetable entities, boosting the quest for novel therapeutic strategies.