Search

OCBIL theory addresses the ecology, evolution, and conservation of biodiversity and cultural diversity on old climatically buffered infertile landscapes, which are especially prominent in southwest Australia and the Greater Cape Region of South Africa. Here, as a contribution to general theory on endemism, a few case studies are briefly discussed to ascertain the relevance of hypotheses in OCBIL theory to understanding narrow endemism in Mediterranean climate regions. Two new conservation management hypotheses are also introduced—minimising disturbance of OCBILS and conserving cross-culturally to achieve best outcomes. Case studies of endemics in southwest Australia (e.g., Eucalyptus caesia, Anigozanthos, Cephalotaceae, Daspypogonaceae) and South Africa (Moraea, Conophytum) and more limited evidence for the Mediterranean Region conform to OCBIL theory predictions. Narrow endemics, concentrated in OCBILs, have diverse origins that embrace major hypotheses of OCBIL theory such as prolonged persistence and diversification in refugia, limited dispersal, coping with inbreeding in small disjunct population systems (the James Effect), special adaptations to nutrient-deficient soils, and special vulnerabilities (e.g., to soil disturbance and removal). Minimising disturbance to OCBILs is recommended as the primary conservation strategy. OCBIL theory has a potentially significant role to play in advancing understanding of narrow endemism of plants in Mediterranean climate regions and elsewhere. [ABSTRACT FROM AUTHOR]

Fabaceae plants contribute greatly to a high quality of pasture in rangelands, because of high levels of protein in their tissues. Despite this established importance, only a few southern African legumes have been evaluated for nutritional value and domestication. The Overberg renosterveld vegetation of the Fynbos biome occupies undulating landscapes that have multiple slope aspects, creating variable microclimatic conditions affecting nutrient dynamics, species richness and plant chemical compositions. We assessed the effect of slope aspect on fiber and mineral composition of forage species present to provide information on the importance of slope for species characterization and nutritional value for domestication. Tissue samples from six replicates of the same species occurring on opposing aspects were collected for nutritional assessment. Results on the data showed that fibre and mineral composition differed in species occurring on different slopes, albeit with few exceptions. The concentrations of P, K and Mg in some species were significantly higher on the cooler and wetter south facing slopes relative to north facing slopes. Nutrient elements in soil samples collected from each site varied with slope aspects and elements. It is recommended that topography should be considered when studying forage nutritional assessments as part of future domestication programs. [ABSTRACT FROM AUTHOR]

OCBIL theory addresses the ecology, evolution, and conservation of biodiversity and cultural diversity on old climatically buffered infertile landscapes, which are especially prominent in southwest Australia and the Greater Cape Region of South Africa. Here, as a contribution to general theory on endemism, a few case studies are briefly discussed to ascertain the relevance of hypotheses in OCBIL theory to understanding narrow endemism in Mediterranean climate regions. Two new conservation management hypotheses are also introduced—minimising disturbance of OCBILS and conserving cross-culturally to achieve best outcomes. Case studies of endemics in southwest Australia (e.g., Eucalyptus caesia, Anigozanthos, Cephalotaceae, Daspypogonaceae) and South Africa (Moraea, Conophytum) and more limited evidence for the Mediterranean Region conform to OCBIL theory predictions. Narrow endemics, concentrated in OCBILs, have diverse origins that embrace major hypotheses of OCBIL theory such as prolonged persistence and diversification in refugia, limited dispersal, coping with inbreeding in small disjunct population systems (the James Effect), special adaptations to nutrient-deficient soils, and special vulnerabilities (e.g., to soil disturbance and removal). Minimising disturbance to OCBILs is recommended as the primary conservation strategy. OCBIL theory has a potentially significant role to play in advancing understanding of narrow endemism of plants in Mediterranean climate regions and elsewhere.

Old, climatically buffered, infertile landscapes (OCBILs) have been hypothesized to harbour an elevated number of persistent plant lineages and are predicted to occur across different parts of the globe, interspersed with other types of landscapes. We tested whether the mean age of a plant community is associated with occurrence on OCBILs, as predicted by climatic stability and poor soil environments. Using digitized occurrence data for seed plants occurring in Australia (7033 species), sub-Saharan Africa (3990 species) and South America (44 482 species), regions that comprise commonly investigated OCBILs (Southwestern Australian Floristic Region, Greater Cape Floristic Region and campos rupestres), and phylogenies pruned to match the species occurrences, we tested for associations between environmental data (current climate, soil composition, elevation and climatic stability) and two novel metrics developed here that capture the age of a community (mean tip length and mean node height). Our results indicate that plant community ages are influenced by a combination of multiple environmental predictors that vary globally; we did not find statistically strong associations between the environments of OCBIL areas and community age, in contrast to the prediction for these landscapes. The Cape Floristic Region was the only OCBIL that showed a significant, although not strong, overlap with old communities. [ABSTRACT FROM AUTHOR]

There are quite a lot of unused plots of lands that are suitable for agriculture or other business in the territory of Lithuania. This has happened because of various social, natural and economic reasons. Scientists emphasize that all intensity of agricultural production is determined by different conditions of development of agricultural activities. Productivity of soil is highly significant in this case. Big farmers control vast territories in which natural conditions are different. Some farmers engage in one type of activities in their farms, whereas others develop different business. Using the territory used for agriculture to engage in different activities is more efficient economically because different crops need different conditions to grow; therefore, it is possible to obtain higher economic efficiency taking into account the characteristics of soil. Taking into account the relevance of such a map in practice, it was decided to try to draw it up using geographic information systems. The biggest problem while performing this task is the fact that initial information is saved in different formats. The article also describes the capacities of software. It is noteworthy that the situation is analyzed in respect of drawing up a map of individual holdings not a mass map of unproductive land. The article is more of practical nature; therefore, the results reflect program capacities and theoretical ideas more that could be useful in business and expand the capabilities of land management officers‘ activities.

Abstract: A revised set of propositions about ecology in arid Australia is presented, based on research literature since publication of . Fourteen propositions distil our argument that most features of the Australian deserts are explicable in terms of two dominant physical and climatic elements: rainfall variability, leading to extended droughts and occasional flooding rains; and widespread nutrient poverty. Different landscapes within the arid zone show these features to varying degrees, and so it is important to think about different places separately when considering our propositions. Plant life-histories strongly reflect temporal patterns of soil moisture; because Australian deserts receive more variable rainfall than most others, there is a distinctive spectrum of life-histories. Low levels of phosphorus (together with abundant soil moisture on irregular occasions) favour plants producing a relative excess of carbohydrate (C). In turn, C-rich plant products sometimes lead to fire-prone ecosystems, assemblages dominated by consumers of sap and other C-based products, and abundant detritivores (particularly termites). Fluctuations in production due to variable rainfall provide openings for consumers with opportunistic life-histories, including inhabitants of extensive but ephemeral rivers and lakes. Most consumer species exhibit some dietary flexibility or utilise more dependable resources; these strategies give rise to greater stability in species dynamics and composition of assemblages than might first be imagined under the variable rainfall regime. Aboriginal people have had long-standing ecological influence as they accessed resources. For each proposition we suggest the extent to which it is ‘different’, ‘accentuated’ or ‘universal’ in comparison with other deserts of the world, recognising that this categorisation is in need of critical testing. Further tests of each proposition are also suggested to fill the many gaps that still exist in our knowledge of the structure and functioning of Australia’s deserts. [Copyright &y& Elsevier]

In an authoritative review on biodiversity conservation in old, climatically buffered infertile landscapes (OCBILs) Hopper (2009) recently argued that Cramer et al. (2008) were ‘overly pessimistic’ to suggest that restoration of historical ecosystems on some old-fields of OCBILs in south-western Australia was unlikely. Here, we argue that this view was realistic rather than pessimistic, and that the conservation of OCBIL biota requires both a radical shift in the willingness of society to make the investment that is currently necessary to restore historical floristically rich OCBILs and further research to find more cost-effective options for broadscale restoration. Advancing the science and practice of ecological restoration in this landscape requires acknowledgement of current constraints. Ultimately, an approach that combines restoration and conservation is required to ensure the persistence of OCBIL biodiversity in the face of ongoing degradation and climate change. [ABSTRACT FROM AUTHOR]

OCBIL theory aims to develop an integrated series of hypotheses explaining the evolution and ecology of, and best conservation practices for, biota on very old, climatically buffered, infertile landscapes (OCBILs). Conventional theory for ecology and evolutionary and conservation biology has developed primarily from data on species and communities from young, often disturbed, fertile landscapes (YODFELs), mainly in the Northern Hemisphere. OCBILs are rare, but are prominent in the Southwest Australian Floristic Region, South Africa’s Greater Cape, and Venezuela’s Pantepui Highlands. They may have been more common globally before Pleistocene glaciations. Based on the premise that natural selection has favoured limited dispersability of sedentary organisms, OCBILs should have elevated persistence of lineages (Gondwanan Heritage Hypothesis) and long-lived individuals (Ultimate Self Hypothesis), high numbers of localised rare endemics and strongly differentiated population systems. To counter such natural fragmentation and inbreeding due to small population size, ecological, cytogenetic and genetic mechanisms selecting for the retention of heterozygosity should feature (the James Effect). The climatic stability of OCBILs should be paralleled by persistence of adjacent semi-arid areas, conducive to speciation (Semiarid Cradle Hypothesis). Special nutritional and other biological traits associated with coping with infertile lands should be evident, accentuated in plants, for example, through water-foraging strategies, symbioses, carnivory, pollination and parasitism. The uniquely flat landscapes of southwestern Australia have had prolonged presence of saline lakes along palaeoriver systems favouring evolution of accentuated tolerance to salinity. Lastly, unusual resiliences and vulnerabilities might be evident among OCBIL organisms, such as enhanced abilities to persist in small fragmented populations but great susceptibility to major soil disturbances. In those places where it is most pertinent, OCBIL theory hopefully lays a foundation for future research and for better informed conservation management. [ABSTRACT FROM AUTHOR]

Yellow serradella (Ornithopus compressus L.) and pink serradella (Ornithopus sativus Brot.) are two new annual forage legume species for infertile, acidic, and light texture soils, in dryland areas of the Mediterranean zone of Chile. Seven cultivars of yellow serradella and one cultivar of pink serradella, developed by the Center for Legumes in Mediterranean Agriculture (CLIMA), Australia, were characterized. O. compressus presented a high to medium hardseededness (53 to 100% at the beginning of the second growth season), while O. sativus presented a very low hardseededness (4%). A variable range of precocity was detected (108 to 143 days to flowering). The growth habit is semi-erect to erect, flowers are yellow in O. compressus and pink in O. sativus. The dry matter and seed production is comparable, and in some years superior, to that of species of traditional use in these areas, like subterranean clover (Trifolium subterraneum L.) and hualputra (Medicago polymorpha L.), standing out serradellas especially for their high production in infertile soils of the interior dry lands of Cauquenes, in the third year of evaluation (2200 to 4200 kg DM ha-1, 650 to 1440 kg seeds ha-1) The available phenological and productive data allow to think that the development of pastures based on serradellas, could mean an important contribution to the improvement of the pastoral production of extensive marginal areas of the non-irrigated Mediterranean land of Chile. [ABSTRACT FROM AUTHOR]

1 The environmental conditions of a site are thought to influence its invasibility by exotic plants. We tested the effects of physical disturbance, water and nutrient addition on growth and survival of a total of 28 plant species from urban bushland remnants on low fertility Hawkesbury Sandstone soils in Sydney, Australia. Species were classified as native (to Australia, including the local community) or exotic (from outside Australia) and as non-invasive or invasive.2 In a glasshouse experiment the treatments were control (natural soil), added water, added nutrients and added water and nutrients. We found significant differences in response of the plant types to additional nutrients but not to water. Under additional nutrients, exotic invasive species had better survival than all other plant types. There were strong biomass responses to added nutrients for all plant types except native non-invasives. In contrast, the survival and growth of all plant types were similar under control and additional water treatments.3 In a field experiment the factors were site (high and low nutrient soils) and physical disturbance but survival differed between plant types only in relation to site. Exotic species had much better survival than native species at the high nutrient site only. Exotic invasive species had the strongest biomass responses to the high nutrient site while native and exotic non-invasive species showed relatively smaller growth responses.4 Differences between invasive and non-invasive plants were not consistent between exotic and native species. Exotic invasives had greater survival than exotic non-invasives under high nutrient conditions in both experiments, and only exotic invasives showed consistently strong biomass responses to nutrient addition. For native species, there were no differences between invasives and non-invasives in survival in high nutrient conditions in the glasshouse or field; however, only invasive species showed a positive growth response to high nutrient conditions.5 This study provides clear evidence that the success of exotic invasive species in this low fertility vegetation community is facilitated by the addition of nutrients. It would appear that on relatively infertile (particularly phosphorus-limited) sites, invasive species cannot take advantage of additional resources provided by physical disturbance or water addition due to overwhelming nutrient-limitation. We suggest that a combination of the environmental conditions (nutrient-enrichment) and invading species having traits that allow high survival and faster growth in response to nutrients, may allow successful invasion in Hawkesbury Sandstone communities.Journal of Ecology(2004) 10.1111/j.1365-2745.2004.00938.x [ABSTRACT FROM AUTHOR]

Summary: Developmental plasticity and nitrogen capture were compared in Agrostis stolonifera and Scirpus sylvaticus grown in compartmentalized root growth arenas which allowed simulation of the spatial and temporal patchiness distinguishing the conditions of mineral nutrient supply associated with fertile and infertile soils. Despite the small root system, higher rates of nitrogen capture and dry matter production were achieved by A. stolonifera at both high and low external concentrations of mineral nutrients. This species also showed a marked ability rapidly to adjust partitioning of growth between parts of the root system, thus allowing local proliferations of fine roots into sectors of high mineral nutrient concentration. Under the conditions of the experiment, this form of plasticity was only weakly developed in S. sylvaticus, which instead maintained a large but relatively unresponsive root mass under each experimental treatment. It is concluded that the high plasticity observed in A. stolonifera allows the dynamic exploitation of fertile soil by competing roots. It is predicted that the more stable pattern of root development in S. sylvaticus will confer a selective advantage in environments where mineral nutrients are strongly limiting upon productivity and become available in temporally unpredictable pulses. [ABSTRACT FROM AUTHOR]