i lhitiibih UNIVERSITY

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1 a: i lhitiibih UNIVERSITY OF SCIEFICE HUD TECHI IOLOGY FACULTY OF NATURAL RESOURCES AND SPATIAL SCIENCES DEPARTMENT OF AGRICULTURE AND NATURAL RESOURCE SCIENCES QUALIFICATION: BACHELOR OF NATURAL RESOURCE MANAGEMENT (NATURE CONSERVSTION) QUALIFICATION CODE: 07BNTC LEVEL: 6 COURSE CODE: NCE51OS COURSE NAME: NATURE CONSERVATION ECOLOGY 1 SESSION: JUNE 2017 PAPER: THEORY DURATION: 3 HOURS MARKS: 150 FIRST OPPORTUNITY EXAMINATION QUESTION PAPER EXAMINER(S) Mrs. C. Ntesa MODERATOR: Mr. H. Tjikurunda INSTRUCTIONS 1. Answer ALL the questions. MODERATOR: 2. Write clearly and neatly. 3. Number the answers clearly. PERMISSIBLE MATERIALS 1. Examination question paper 2. Answering book 3. Scientific calculator THIS QUESTION PAPER CONSISTS OF 6 PAGES (Including this front page)

2 QUESTION 1 Write short notes to define or explain the following: 1.1. Biomes 1.2. Bush encroachment 1.3. Net primary production (NPP) 1.4. Cation exchange capacity 1.5. Global warming QUESTION 2 Provide the word(s) which best fits the definition or description below: 2.1. An animal that mainly eats grains A soil horizon which often has a higher concentration of clays, iron, aluminium oxides and lime than above horizons Organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries, and even millennia The weather system that brings rain to Namibia from the north The quantity of water retained by a soil after drainage Refers to the number of individuals at each trophic level The study of a single species in relation to other component of the ecosystem Percentage of available sunlight used in photosynthesis A term referring to the part of the soil volume that is not occupied by solid particles The type of competition that occurs when jackals chase vultures away from a carcass. (l) [10] QUESTION Explain the ecological role of decomposers and detritivores. Give an example for each. (4) 3.2 Explain how the understanding of ecology and the maintenance of ecosystem health is important for tourism. (3) [7] QUESTION Describe the rainfall situation in Namibia, referring to the general situation, the differences between different areas or gradients from area to area, as well as the (8) weather systems/climatic zones that influence Namibia's rainfall. It is not necessary to give actual rainfall amounts in your answer.

3 L - V 4.2. Look at the diagram below and answer the questions that follow: :,v vif";;" V. i. \ :V:.: J l An average rainfall amount of 600 mm is received in Katima Muiilo during the 2016/2017 rainy season. a) How much (in mm) is likely to recharge the groundwater, given the average % for groundwater recharge in Namibia? Given that the rainshower mentioned above occurred on a steep slope, and occurred in a space of one hour, is the amount of groundwater recharge (for the area under the slope) likely to a) be the same as b). above or c). below the answer given in ? Choose between a, b, and c and then motivate your choice by referring to the hydrological cycle Explain how soil structure influences the hydrological cycle (how it affect the different parts of the hydrological cycle such as evaporation, infiltration, etc.). Explain using examples of soil structure. (2) (4) [15] QUESTION Explain why in dry climates such as in Namibia soils form slowly Draw and clearly label a typical soil profile showing the different soil horizons Briefly give the main characteristics of any of the two horizons. (5) (5) (4) [14]

4 » QUESTION 6 The following results were obtained from soil analyses. Study these results and answer the questions below: Location Texture Nutrients ph Rainfall Vegetation (overall) Type Kavango (60 km E of Sand Very Low mm Woodland Rundu) Savanna Friedenau Dam (from Loamy Sand Medium mm Highland under Acacia me/lifera) Savanna Friedenau Dam (from an Loamy Sand Medium mm Highland open area) Low Savanna Grootfontein (pediment* Silty Clay Very high mm Thornbush soil, downslope of dolomite** mountains) * pediment is the soil below a slope in a valley ** dolomite refers to the parent rock which is rich in calcium carbonate Savanna 6.1. Explain fully why the nutrient level of the Kavango soil is very low. (3) 6.2. Explain fully why the Grootfontein soil is so nutrient rich. (4) 6.3. Explain why clays have a high field capacity. Why is it still possible that a plant in a clay soil (4) with a high field capacity may wilt and die from lack of moisture? [11] QUESTION Differentiate between species richness and species diversity. (3) 7.2. In a survey to determine the relative abundance of different grass species at Avis Dam and Goreangab Dam, using the descending point method, the following results were obtained: Species Avis Dam Goreangab Dam Schmidtia pappaphoroides 15 2 Anthephora pubescens Brachiaria nigropedata 15 1 Enneapogon cenchroides 13 2 Schimidtia kalahariensis 5 3 Eragrostis nindensis 7 6 Digitaria eriantha 8 2 Fingerhuthia africana Which grass species is the most dominant at each dam and what is its relative (6) dominance?

5 Which dam has the highest grass species diversity? Explain. (2) The communities represented by the above grass species is a a. pioneer or b. climax (3) community? Explain your choice Explain how spatial heterogeneity (horizontal heterogeneity) and community structure (6) (vertical heterogeneity) influences species diversity. [20] QUESTION 8 Consider 2 food chains: grass grass > > cow >human; grasshopper >hawk. In which will there be a more efficient flow of energy? Give reasons. QUESTION 9 Why are open ocean food chains some of the longest in the world, whereas, often high rainfall woodland ecosystems have short food chains? [7] QUESTION 10 Discuss (not just list) four factors that can affect assimilation efficiency at each trophic level, and say whether each factor would increase or decrease assimilation efficiency. [8] QUESTION 11 Draw a well-labelled diagram of the nitrogen-cycle clearly showing the processes and the soil bacteria involved in the different processes. [15] QUESTION Differentiate between climate change mitigation and climate change adaptation. (2) Explain how man has disrupted the carbon cycle? (5) Climate change is a global concern that is likely to pose consequences on various sectors (3) such as water, agriculture, and biodiversity in general. To date, Scientists have observed trends in rainfall in Namibia. Explain these trends. [10]

6 QUESTION 13 Briefly interpret this diagram, using the terminology on optimum range, zone of physiological stress, zone of intolerance, narrow and wide tolerances. Welwz'tschia mirabilz's Acacia reficiens Semi arid _ Hyper arid QUESTION Name three possible outcomes of competition Discuss the natural functioning of a healthy savannah ecosystem, showing how each of the processes plays a role in maintaining the balance between woody plants and (3) (9) grass. [12] QUESTION 15 Compare the following characteristics of a pioneer community to those of a climax community. in a table format. Do so Characteristics Pioneer community Climax community Plant longevity Most energy is invested in? Plant species diversity Complexity of food webs Rate of Net Primary Productivity TOTAL: 150 marks