...a disturbance is followed by colonization or re-growth of the disturbed site by plants • Natural, gradual changes in the types of species that live in an area; can be primary or secondary • The gradual replacement of one plant community by another through natural processes over time Causes of Plant Succession • Autogenic succession (2 types) can be brought by changes in the soil caused by the organisms there. These changes include accumulation of organic matter in litter or humic layer, alteration of soil nutrients, change in pH of soil by plants growing there. The structure of the plants themselves can also alter the community. For example, when larger species like trees mature, they produce shade on to the developing forest floor that tends to exclude light-requiring species. Shade-tolerant species will invade the area. • Allogenic changes are caused by external environmental influences and not by the vegetation. For example soil changes due to erosion, leaching or the deposition of silt and clays can alter the nutrient content and water relationships in the ecosystems. Animals also play an important role in allogenic changes as they are pollinators, seed dispersers and herbivores. They can also increase nutrient content of the soil in certain areas, or shift soil about (as termites, ants, and moles do) creating patches in the habitat. This may create regeneration sites that favor certain species. 2 main types of Autogenic successions • Primary...
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...and are left with essentially no plant growth at the beginning – Examples: glacial retreat; volcanic ash deposition Mt. St. Helens May 18, 1980 Gilkey Glacier, Alaska from www.geophot.de • Secondary succession – Established plant community has been destroyed but without severe disturbance of the soil – Example: forest succession following wildfire - pioneer forest re-establishes and is eventually replaced with climax forest wildfire from www.us.gov 1 Plant Succession • Seral stages • Climax stage Stages of Succession • Seral communities: The various “temporary” communities in the succession • Seral species - those that will ultimately be replaced • examples: annual plants, shrubs, intolerant trees Stages of Succession • Climax community: The “final” stage of the succession consists of those plants that can reproduce successfully beneath their own shade and therefore maintain the community indefinitely under the prevailing conditions • Climax species: Those species that will occupy the site at the climax stage of succession • Examples: tolerant tree species such as cedar and hemlock eastern white pine invading old field Harvard Forest diorama slide collection shrub species at Mt. St. Helens photo by John Donohue – 1995 or 1996 eastern white pine...
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...Submit your answers in a separate Word document. List the question number and the letter of the best answer for each of the 50 questions. 1. The rapid population increase since the Industrial Revolution occurred for all of the following reasons except: A) invention of vaccines B) advances in agriculture C) increased food production D) lower infant mortality E) declining birth rates 2. When did the most dramatic increase in the history of the human population occur? A) in the early history of the human population B) in the last part of the twentieth century C) during the industrial revolution D) during the middle ages E) human population has increased on a steady rate 3. An observation that is agreed upon by the majority of scientists is called a A) hypothesis B) controlled experiment C) technology D) theory E) fact 4. Considering inputs to a pool and outputs from it, the pool will be in steady state when: A) inputs exceed outputs B) outputs cease C) inputs equal outputs D) outputs exceed inputs E) inputs cease 5. Which of the following parameters is/are necessary to describe exponential population growth? A) carrying capacity B) population size C) juvenile death rate D) time lag E) all of these Page 16. The “demographic transition” leads to: A) an increase in population growth rate B) an decline in population growth rate C) an increase in the birth rate D) a decline in the death rate E) all of these; it is a four-stage pattern of population...
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...Question 1 Most insects use external sources of heat to achieve their operative temperature range. Heinrich's research on the sphinx moth (Manduca sexta) indicates that some insects can thermoregulate by using their flight muscles and: A. using their blood as a coolant. B. decreasing their metabolic rate. C. possessing an internal respiratory system. D. using a countercurrent heat exchange mechanism. Question 2 The thermal stability of aquatic environments is a result of the: A. high specific heat of water. B. low latent heat of vaporization of water. C. low latent heat of fusion of water. D. All of the choices are correct. Question 3 Animals that rely mainly on external sources of energy for regulating body temperature are called: A. epitherms. B. endotherms. C. ectotherms. D. peritherms. Question 4 In general, reptiles are considered to be a/an: A. poikilotherm. B. homeotherm. C. endotherm. D. heterotherm. Question 5 Mammalian and avian aquatic endotherms use all of the following mechanisms to thermoregulate EXCEPT: A. fat. B. internal respiratory systems. C. fur or feathers. D. concurrent heat exchange. Question 6 The water availability for organisms is determined by: A. internal dissolved ion concentrations. B. external dissolved ion concentrations. C. movement of water down its concentration gradient. D. movement of water...
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...the seedling will determine the ability of seedlings to germinate, become established, survive, and grow. Among the factors affecting growing conditions at any site, the one that, if increased, will result in the greatest corresponding increase in productivity of the stand, is considered to be the “most limiting factor”. ABIOTIC FACTORS BIOTIC FACTORS REGENERATION HANDBOOK 1 Limiting Factors Light and Space. All growing plants require sunlight for photosynthesis…trees included! For most tree species in the Northeast, light availability is the most limiting factor to successful regeneration. Species that compete best in full sunlight have the capacity for rapid height growth and are often found in the upper layers of the forest canopy. Species that are able to compete in the shade of other trees can occupy lower layers in the canopy, and each canopy layer will intercept additional...
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...Energy Flow in Ecosystem and Its Importance in Crop Production By gachura10@gmail.com Course Tutor Institution, City Date Energy Flow in Ecosystem and Its Importance in Crop Production Introduction An ecosystem is made up of of the organic community that take place in some area, and the bodily and biochemical influences that make up its lifeless or abiotic environs (Fraham, 1984: 143). There are several instances of ecosystems: a fish pond, a plantation, a river mouth, a savannah. The limits are not static in any impartial way, even though occasionally they look clear, as with the water's edge of a small fish pond. Typically the margins of an ecological unit are selected for real-world aims having to do with the objectives of the specific study. According to Perry (2008), study of ecological unit mostly comprises of the study of sure procedures that relates the living, or biotic, constituents to the inorganic, and abiotic constituents. Energy changes and biogeosubstance transformation are the key procedures that include the area of environment conservation. Ecology normally is well-defined as the connections of creatures with one another and with the environs in which they are living. Ecology can be studied at the level of the separate organism, the inhabitants, the community, and the environment. studies of ecology at individuals are concerned generally about composition, reproduction, growth or performance, while studies of ecology at inhabitants...
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...Biology 2F03: Lecture 1 Chapter 2: Life on Land • • • • • • • • Labs start on the Sept 17 Why horses and cattle help restore Guanacaste forest of Costa Rica? o This forest was in decline for thousands of years, when Indians colonized central America, it caused its decline. o Its regenerated when the Europeans came with the cattle o The trees only produce a new plant after processes: the fallen fruit has to be eaten by a larger animal (mule, or horse or cow) à it has to pass through the body and ends up in a pile of fertilizer only then it can regenerate and produce a tree o Why did it evolve to be depended to this process? § There must be animals there in the past, in the past it was a camel (llama, alpaca). When the Indians came from asia (50000 years ago) these animals went extinct and the tree lost its major dispersal system What is the most obvious foundation of life on land? o Is landà soil Climate defines biomes, the ‘shapes’ of vegetation o Defines the major types of land on earth o Temperature and precipitation to be specific Soils in turn greatly affect the aspects (roots, water, nutrient) à rentention, root attachment, etc. Soil typically form layers (horizontal) retaining a range of physical and chemical layers: o Classification of soil: O= organic, A, B, C Soil horizons: description o O: organic, litter on top, fine litter deeper (gets broken down, hence fine), pollen, dead organisms o A: mineral soil, some organic matter...
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...(Mudra), Sushma Durve Manuscript review and editing – Chinmaya Dunster, Behafrid Patel Artists – Sushma Durve and Anagha Deshpande CD ROM – Jaya Rai and Prasanna Kolte © Copyright Text – Erach Bharucha/ UGC, 2004. Photographs – Erach Bharucha Drawings – Bharati Vidyapeeth Institute of Environment Education and Research All rights reserved. Distributed by University Grants Commission, New Delhi. 2004. ii Environmental Studies for Undergraduate Courses Preliminary Pages.p65 2 4/9/2004, 5:06 PM Vision The importance of Environmental Studies cannot be disputed. The need for sustainable development is a key to the future of mankind. The degradation of our environment is linked to continuing problems of pollution, loss of forest, solid waste disposal, issues related to economic productivity and national as well as ecological security. The increasing levels of global warming, the depletion of the ozone layer and a serious loss of biodiversity have also made everyone aware of growing environmental concerns. The United Nations Conference on Environment and Development held in Rio De Janero in 1992, and the World...
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...Edited by Kristen Walker Painemilla, Anthony B. Rylands, Alisa Woofter and Cassie Hughes Edited by Kristen Walker Painemilla, Anthony B. Rylands, Alisa Woofter and Cassie Hughes Conservation International 2011 Crystal Drive, Suite 500 Arlington, VA 22202 USA Tel: +1 703-341-2400 www.conservation.org Editors : Kristen Walker Painemilla, Anthony B. Rylands, Alisa Woofter and Cassie Hughes Cover design Paula K. Rylands, Conservation International : Layout: Kim Meek, Washington, DC Maps [except where noted otherwise] Kellee Koenig, Conservation International : Conservation International is a private, non-profit organization exempt from federal income tax under section 501 c (3) of the Internal Revenue Code. ISBN 978-1-934151-39-6 © 2010 by Conservation International All rights reserved. The designations of geographical entities in this publication, and the presentation of the material, do not imply the expression of any opinion whatsoever on the part of Conservation International or its supporting organizations concerning the legal status of any country, territory, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. Any opinions expressed in this publication are those of the writers, and do not necessarily reflect those of Conservation International (CI). Suggested citation: Walker Painemilla, K., Rylands, A. B., Woofter, A. and Hughes, C. (eds.). 2010. Indigenous Peoples and Conservation: From Rights to Resource Management. Conservation...
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...Park Design Guidelines & Data Province of British Columbia Ministry of Environment Lands and Parks A NATURAL LANDSCAPE ARCHITECTURE FOR BRITISH COLUMBIA’S PROVINCIAL PARKS BC PARKS: PARK DESIGN GUIDELINES & DATA Overview Simplicity in design and restraint in construction creates park facilities suited to what attracts visitors in the first place – recreation in the natural park landscape. q The aim of Park Design Guidelines & Data is to help BC Parks staff use their park expertise to produce appropriate facility landscapes. These guidelines identify design criteria and planning processes for BC Parks staff to provide sustainable, appropriate park recreation facilities. They promote facility design that requires the least visible development. q A design approach to visitor facilities is defined that: Recognizing the facilities are an integral part of a park means reducing the impact of use and basing planning and design decisions on local and regional considerations – for the park environment’s long term health. Maintaining natural park landscapes and environments will help ensure the quality of visitor experiences now and in the future. At neighbouring Bromley Rock Provincial Park and Stemwinder Provincial Park, illustrated left, natural site elements create facilities that blend into the natural park landscapes. These examples show the careful expenditure of resources and the thoughtful use of native materials...
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...文勇的新托福精选阅读（原黄金29篇）真题[2010年4月3日 5.8版本] 俺常常收到同学们的邮件，要我推荐各种各样阅读材料,问我iBT的复习资料中 Barron, Longman, Delta等等哪个更好。我其实很无奈---因为尽管这些机构很大牌,但大牌丝毫都不意味着文章“质量高”(比如你可以想想三鹿奶粉)---说这些机构的文章质量不高,并不是说文字写得不好,而是说这些文章的句子结构, 论述方式, 出题思路与ETS的并不一致(有时候甚至大相径庭)：用这样的材料训练，实在是 事倍功半。 于是，我们实在应该去找找由ETS出的iBT文章来做：（我们能够找到的|由ETS编纂的标准iBT文章有） 1. OG[1]之中的13篇文章[2]；（其中3篇为第三版OG之中的文章） 2. 13次（套）TPO[3]之中的3*13=39篇文章[4]； 3. 早期[5]报名之时ETS赠送的3篇在线测试题 4. ETS官方给出的模考软件之中抽出的1篇文章； 于是这个文档在我的一时兴起之下，出现了： OG拿在手上，可以一个个字的敲成电子版；TPO的所有考试都是在自己的计算机进行，于是可以一边花钱参加考试,一边截图与录像---再利用截下来的图片，逐个的敲下来；早期的ETS赠送的3篇在线测试题，我也恰好有电子版本；官方的模考软件稍微用点功夫，就能将文章提取并复制出来。虽然工作有些繁杂，但总算完成了所有文章的敲打工作。再花了些时间，把这53篇文章都做了答案，附在文章的后面。（由于TPO之中有3篇文章与OG中完全重复,于是减去3篇,只剩下53篇。）同时我还更正了OG上几个明显的错误（详见文后附录）当然，我还做出了方便大家理解文章的参考译文，附在文章的后面。 在这53篇由ETS出的文章没有做完之前，我们实在不应该花时间在任何其他的题目之上。我有时候甚至会对着我的弟兄们高呼：“没有把这53篇做３遍，你好意思上考场么？你好意思花钱在任何一本垃圾书上面么？[6]” 另外，如果你正在准备iBT-SAT-GRE的作文部分或者写留学文书，也应该仔细的琢磨一下这些文章：经过ETS打磨的文章，无一不是精妙绝伦，极具模仿价值。常常有同学拜托我帮她（他）写PS，也说起自己的句子怎么看都像是小学生写的（尽管用上了GRE里面的单词），于是会随口问我“勇哥，您的写作能力是怎么训练出来的。”我说，“看呗，看呗：托福文章看多了，写作能力自然就提高了。” “这ETS的这些文章真的那么好？”。每当听到这个问题，我都会装做赵本山的样子来一句“谁用谁知道～～” 文勇 欢迎进行未删节的转载|且不必告诉我你转载到哪里去|都是一个战壕里面的弟兄啊… 告诉大家一个好消息，本文档中的TPO1-TPO9，以及在线测试题和官方模考题目的解析已经在市面上可以买到了！（好吧，我承认以下显然是广告部分）： 这本《托福真题详解-阅读分卷-第一册》是给弟兄们现在市面上可以获得的TPO1-TPO9阅读部分的文章解析，题目解析，中文翻译和每篇文章的必备词汇：文章解析是为了让大家养成从整体抓文章结构的感觉，题目解析是为了使大家能够在做完题之后知道正确选项为什么对，错误选项为什么错——并且因此来培养良好的做题思路，中文翻译是为了帮助大家扫除那些自以为理解对但实际理解有误的句子，在每篇文章后面配上必备词汇无非是为了节省大家的一些查单词而已。 另外，这本书还包含了一张CD（我想你可能第一次听说阅读书...
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...Published by the Ecological Society of America Number 10, Winter 2003 Issues in Ecology Sustaining Healthy Freshwater Ecosystems Issues in Ecology Number 10 Winter 2003 Sustaining Healthy Freshwater Ecosystems SUMMARY Fresh water is vital to human life and economic well-being, and societies extract vast quantities of water from rivers, lakes, wetlands, and underground aquifers to supply the requirements of cities, farms, and industries. Our need for fresh water has long caused us to overlook equally vital benefits of water that remains in stream to sustain healthy aquatic ecosystems. There is growing recognition, however, that functionally intact and biologically complex freshwater ecosystems provide many economically valuable commodities and services to society. These services include flood control, transportation, recreation, purification of human and industrial wastes, habitat for plants and animals, and production of fish and other foods and marketable goods. Over the long term, intact ecosystems are more likely to retain the adaptive capacity to sustain production of these goods and services in the face of future environmental disruptions such as climate change. These ecosystem benefits are costly and often impossible to replace when aquatic systems are degraded. For this reason, deliberations about water allocation should always include provisions for maintaining the integrity of freshwater ecosystems. Scientific evidence indicates that aquatic ecosystems can be protected...
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