Teaching for community environmental action: an alternative instructional model for environmental concepts and issues in schools

Summary Whether environmental education in the school curriculum is treated as a separate subject or as an interdisciplinary entity, the end product should be the same: to provide learners with the desire to preserve or develop optimum environments and to improve less desirable ones. In this endeavour, the learners must ultimately reach out to participate in community decisions and environmental management activities, for that is where the environmental problems abound. Moreover, young persons are generally more knowledgeable than many adults on environmental matters and are more aware of the effects of environmental degradation. When they participate in community environmental management, they may also develop unique and particularly dynamic qualities.Research worldwide suggests that very few teaching programmes encourage environmental participation. In Kenya teachers tend to use deductive teaching methods which do not encourage participation, although there may be ample opportunities in the local environment to facilitate such participation. A more refined, reconstructivist inquiry strategy, committed to the attainment of participative environmental education objectives is suggested. The approach, referred to as an operation-environment instructional model emphasizes action research, supported by a series of other vital stages, as fundamental to the agenda for environmental learning.William W. Toili possesses both Bachelor and Master's Degrees in Education from Nairobi as well as a Master's Degree from the University of Leeds, UK. He is currently a lecturer in Environmental Education at Maseno University College.     

SIMULATION OF TEMPORAL CHANGES IN RAINFALL-RUNOFF CHARACTERISTICS,COON CREEK BASIN,WISCONSIN1

ABSTRACT: Streamflow for 67 years was simulated for Coon Creek at Coon Valley, Wisconsin, for three conditions in the drainage basin: (1) conditions in the 1930s; (2) conditions in the 1970s, excluding flood-detention reservoirs; and (3) conditions in the 1970s, including flood-detention reservoirs. These simulations showed that the changes in agricultural practices over 40 years (1940–80) reduced the 100-year flood by 53 percent (from 38,900 to 18,300 cubic feet per second). The flood-detention reservoirs reduced the 100-year flood by an additional 17 percent (to 15,100 cubic feet per second). The simulation was accomplished by calibrating a precipitation-runoff model to observed rainfall and runoff during two separate periods (1934–40 and 1978–81). Comparisons of model simulations showed that differences between the model calibrations for the two periods were statistically significant at the 95 percent confidence level.     

Will Observation Error and Biases Ruin the Use of Simple Extinction Models?

Abstract: Estimating the risk of extinction for populations of endangered species is an important component of conservation biology. These estimates must be made from data that contain both environmental noise in the year-to-year transitions in population size (so-called "process error"), random errors in sampling, and possible biases in sampling ( both forms of observation errors). To determine how much faith to place in estimated extinction rates, it is important to know how sensitive they are to observation error. We used three simple, commonly employed models of population dynamics to generate simulated population time series. We then combined random observation error or systematic biases with those data, fit models to the time series data, and observed how close the extinction dynamics of the fitted models compared with the dynamics of the underlying models. We found that systematic biases in sampling rarely affected estimates of extinction risk. We also found that even moderate levels of random observation error do not significantly affect extinction estimates except over a small range of process errors, corresponding to the region where extinction risk is most uncertain. With more substantial sampling error, estimates of extinction risk degraded rapidly. Field census techniques for a variety of taxa often involve observation errors within ±32% of actual population sizes. For typical time series used in conservation, therefore, we often may not need to be overly concerned about observation errors as an extra source of imperfection in our estimated extinction rates.     

Demographic Forecasting in Koala Conservation

Abstract: The koala currently needs conservation intervention. There is clear evidence of decline in many populations, but the existence of other stable or expanding populations offers the possibility of a variety of creative solutions to their conservation problems. The 1998 National Koala Conservation Strategy emphasizes the need to obtain demographic information and to use this information to assess management options for koalas. We need accurate diagnoses of the status of koala populations and forecasts of their demographic future with and without particular management actions. In a qualitative fashion, this process has been undertaken many times on a local and national scale. Quantitative demographic forecasting tools are increasingly available, and koala management could benefit from their application both at the scale of individual populations and more broadly. There is already a considerable body of suitable data on the dispersal, effects of normal and catastrophic environmental variation on reproduction and survival, and on the effects of habitat change. Demographic forecasting, however, is hampered because the full suite of information is rarely available from a single population. In two Queensland populations, retrospective population viability analyses provided forecasts that were in agreement with observed population trends. Work is needed to determine whether data from one population can be applied to other populations. Models can then be developed to make projections at a multipopulation level on the basis of local population dynamics and dispersal. Certain koala populations, because of their long history of study, offer the opportunity to test demographic models retrospectively. These tests will not only aid in fine-tuning the models for koala biology and data but will also assist with the more general process of validating the models.     

The sands of Forvie (Scotland): A case study in geomorphology and conservational management

The Sands of Forvie, National Nature Reserve, Scotland is a complex coastal sand dune system which is associated with the dynamic estuary of the River Ythan. The dune system has developed over more than 5000 years. The south part is a peninsula of dunes, sand hills, sand arcs, erosion and deflation surfaces. The north part is superimposed on a rock plateau with a cliff coastline. This plateau is covered in glacial deposits and is essentially an upland heath landscape. Some of the best examples of large active parabolic dunes in Britain are found in North Forvie. The sequence of geomorphic development is described. As a nature reserve with a rich ecology it has been managed for conservational purposes since 1960s. As such it is an excellent case study of how conservational management has changed to become more flexible and more aware of the importance of dynamic processes.