This course aims at enabling students to acquire a knowledge on ecological principles which serve as a basis for the understanding of functional aspects of aquatic systems and for their management.
Before attending this course, students must have completed basic ecology courses and possess an adequate background on relevant ecological theories and principles.
Course unit content
In the first part of the course are considered some of the studies on freshwater systems that have contributed to the formulation of important concepts and theories in ecology. The value of inland waters in terms of ecosystem services is also highlighted.
Then it follows a series of lectures on basic limnological concepts about origin and morphology of lake basins, and physical and chemical characteristics of the water. The next section is devoted to the analysis of the main freshwater communities, biotic interactions, and functional adaptations, with particular reference to the pelagic zone of lakes.
The part of the course dealing with stream ecology considers structural, trophic and biological aspects of lotic systems. Patterns and processes are then integrated and discussed in the light of the major paradigms and theories developed in recent decades.
Some lecture are devoted to the study of interstitial and groundwater systems, with emphasis on functional and ecological aspects.
The last part is dedicated to the analysis of aquatic biodiversity and its role in the functioning of ecosystems.
During the course, scientific articles fundamental to understand the evolution of freshwater ecology as well as reviews on relevant topics covered in class are discussed.
The study of inland waters and the formulation of concepts and theories in ecology. Definition of wetlands. Environmental value and functions of wetlands. Features of the water molecule. Heat budgets of lakes. Temperature profiles in temperate lakes. Oligomixis, holomixis and meromixis. Light in lakes. Incident light penetration. Extinction coefficients. PAR. Measurement of light penetration. Dissolved oxygen. Oxygen concentration and saturation. Dissolved oxygen vertical distribution in lakes. Inorganic carbon. The carbonate/bicarbonate buffering system. Total alkalinity and ANC. The Redfield ratio. The role of phosphorus in aquatic systems. Nitrogen cycling in surface waters. Classification of the aquatic communities. Main types of freshwater phytoplankton. Factors affecting algal growth and seasonal succession. Physiological adaptations of phytoplankton to light. Stokes' law. Porter’s and Reynolds’ functional classifications. The paradox of plankton. The herbivorous zooplankton: micro- and macrofilter feeders. Predation of vertebrates and invertebrates upon zooplankton. Biotic interactions in the pelagic zone. Top-down and bottom-up control in lakes. Plankton vertical migration. Cyclomorphosis. Dormancy: quiescence and diapause. Strategies to avoid the harmful effects of ultraviolet radiation. River ecology. Structural and functional aspects of river ecosystems. Autotrophy and heterotrophy. Fate of the organic matter. Biological communities in running waters. The River Continuum Concept. The Flood-pulse Concept. Nutrient spiralling. Lakes and trophic state. Point and nonpoint sources of pollution. Trophic state criteria and nutrient loading criteria. Carlson's Trophic State Index. Open and fixed boundary systems. OECD trophic classification methods. Vollenweider’s models. Biological monitoring of lakes and streams. Indexes for the assessment of river water quality and functioning. Ecology of interstitial waters and groundwaters. The biodiversity of inland waters. Biological invasions.
Bettinetti R., G. Crosa, S. Galassi. 2007. Ecologia delle acque interne. Edizioni CittàStudi.
Fenoglio S., T. Bo. Lineamenti di ecologia fluviale. Edizioni CittàStudi.
Bertoni R. 2006. Laghi e scienza. Introduzione alla limnologia. Aracne Editrice.
Reading materials (e.books, scientific papers, etc.) will be available from the teacher’s website.
Regular class lectures and seminar activities. Whenever possible, field trips will be performed.
Assessment methods and criteria
After completing this course students are able to understand and analyze the structure and main characteristics of freshwater ecosystems and related processes. This background enables students to deal with the study of environmental problems with different levels of complexity.
The exam consists in a written test composed of closed-ended and open-ended questions on topics covered during the course, with particular attention to applying knowledge and understanding, making judgements, and learning skills. Each question has a different score, which is clearly indicated on the answer sheet. The exam is passed with a score of at least 18. The maximum possible score is 35; score greater than or equal to 32 corresponds to 30 cum laude. Optionally, students can prepare and discuss a minireview on a topic of freshwater ecology assigned by the teacher. The extra credit points awarded (up to a maximum of 2) will be added to the student's score obtained in the written test. Extra marks may be awarded for specific activities, such as in-class presentation and discussion of case studies, participation in workshops/seminars, etc. In any case, it is mandatory to register for the oral exam to eventually proceed with the recording of the grade earned through the exam.
As long as it is not possible to do face-to-face exams, the learning verification will be carried out by means of an oral exam at a distance using Teams.
If the number of participants to an exam session is particularly high, the exam will be scheduled according to the order of registration.
Lectures are held in Italian, but Erasmus/foreign students can complete the course by choosing the “book exam” option: this means that these students can read and study the literature specifically agreed on with the professor and then take a written examination in English.