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Coyne M.S. 1999. Soil Microbiology. Delmar Publishers. Ch. 4 The macrofauna.
Soil Biology Primer [online]. http://soils.usda.gov/sqi/concepts/soil_biology/
Chapter 1 The soil food web
Chapter 2 The food web and soil health
also check the DSO Resources folder for other references.
Introduction
An ecosystem is made up of plants, animals (biodiversity) and abiotic factors which work
together to capture, store and transfer energy, nutrients and water. For example plants “capture”
energy via photosynthesis and energy is stored as carbohydrates in plants or fats and proteins in
animals after they have eaten the plants. Soil organisms break down plant and animal tissues
and transfer the energy to themselves, while returning nutrients to the soil for uptake by plants.
The many organisms in an ecosystem carry out these ecosystem functions, and the more
diverse an ecosystem is, the more stable and reliable are these functions. The soil provides a
good, easily studied example of an ecosystem.
The Task Assessing macrofauna
1.1 Macrofauna accelerate the rate of organic matter decomposition. They break organic
material into smaller pieces, and mix organic matter with soil. However, the relative numbers of
macrofauna to microfauna in the soil is small.
Collect a sample of the leaf litter (O Horizon) and topsoil (A Horizon – no deeper than about
3cm) from two different locations. Choose from lawn, native vegetation, garden bed, under
different species of tree etc. or other distinctive site. Place the sample in plastic bags, seal them
and label them with your name and the collection location. At each site, record the type of
vegetation at the site (eg. forest, swamp, lawn etc.) and some of the site characteristics in the
table below, then use this to compare the soil habitat of the two sites. If you do not have the
equipment necessary (eg. pH kit or soil penetrometer), skip that characteristic.
Site Characteristic Site 1 Site 2
type of vegetation
level of shade
soil dryness/dampness
soil pH
soil compactness
soil texture (sandy, heavy clay etc)
On return to the lab, mix the soil and leaf litter sample from the same location thoroughly. Put a
known volume of one sample in the Tulgren funnel. Leave it for about 2 days, then remove the
preserving jar containing ethanol and screw on the lid. Place the sample from the second
location in the Tulgren funnel, and remove after about 2 days, following the same procedure. If
you know the volume of soil you examined, you will be able to directly compare the macrofauna
abundance between the two sites.
Tulgren
Funnel
1.1 From the bags, examine a measured volume of the leaf litter (O Horizon) and the
topsoil (A Horizon) using a microscope or hand lense. Remove any fauna found to a clean jar or
petri dish for identification. Identify all organisms to Order if possible, but at least put them into
different groups (ie. group A no legs – worms; group B 8 legs – spiders and mites etc.). Count
the number of individuals from each Order or group. If you have large numbers you may need to
estimate the number rather than try to count them all.
1.2
(a) larger macrofauna
Macrofauna Order
or group
number @ location 1
soil volume = ____
number @ location 2
2
soil volume = ____
1.3 Empty the contents of the collecting jar into a petri dish, and identify as many
organisms as possible to Order or group. Count the number of individuals from each Order or
group (as far as possible).
(b) smaller macrofauna
Macrofauna Order
or group
number @ location 1
soil volume = ____
number @ location 2
soil volume = ____
1.4 Use the results from both counts (1.2 and 1.3) and calculate the number of Orders or
groups per litre of soil and leaf litter, and the numbers of individuals from each Order or group
per litre of soil and leaf litter.
Macrofauna location 1
location 2
number of Orders or groups per litre of soil/litter
eg. no. individuals of group B per litre of
soil/litter
15 7
no. individuals of per litre of soil/litter
no. individuals of per litre of soil/litter
Your Report - Explaining the role of the soil biota
Your report should have a title, a brief introduction explaining what the prac is about, and a brief
discussion (about 600 words) of the following questions. You must also include a summary table
of your results. This report can be written as a “question and answer” style, but it must be
correctly referenced
Foodweb
1. How did the diversity (number of groups and number of individuals) of macrofauna from the
soils from the two locations differ ? Can you suggest why there might be differences. What soil
parameters could you have measured which may help explain the differences ?
2. Explain the role of macrofauna in the soil.
3. On the food web diagram provided, label the type of biota (eg. fungi, nematode etc.). what
they do (predator, leaf shredder etc) and describe which way the energy “flows” eg. where does
it first get “captured” and where does it “finish” (ie. the top of the food chain). What happens to
the energy and nutrients when the organisms at the top of the food chain die? Include this
diagram with your report
What groups of organisms make up the mesofauna ?
What groups make up the microfauna?
What are the main functions of these two main groups ?
Due Date
Check the Assessment Details File for the date. This report is worth 10% of your total mark.
Amali 1
Ekosistem Tanah - Biota Tanah dan Jaringan Makanan
Pendahuluan
Sesuatu ekosistem terdiri daripada tumbuhan, haiwan (biodiversiti) dan faktor-faktor abiotik
yang bekerja bersama untuk menjana, menyimpan dan memindahkan tenaga , nutrien
dan air. Sebagai contoh, tumbuhan menjana tenaga dari proses fotosintesis dan tenaga
disimpan dalam bentuk karbohidrat dalam tumbuhan atau lemak dan protin dalam haiwan
selepas haiwan memakan tumbuhan tersebut. Organisma-organisma tanah menguraikan
tisu-tisu tumbuhan dan haiwan dan memindahkan tenaga kepada mereka manakala nutrien
balik ke tanah untuk diambil balik oleh tumbuhan. Kebanyakan organisma dalam
ekosistem ini menghasilkan fungsi –fungsi ekosistem dan menyumbang kepada lebih
kepelbagaian dan kestabilan kepada ekosistem itu sendiri. Tanah menyediakan satu contoh
kajian ekosistem yang mudah.
Tugasan: Mengukur Makrofauna
Makrofauna mempercepatkan kadar pereputan bahan organik. Mereka memecahkan bahan
organik menjadi lebih kecil dan menggaulkan bahan organik dengan tanah. Walaupun begitu,
bandingan bilangan makrofauna dengan mikrofauna dalam tanah adalah kecil.
Kumpul satu sampel tanah dibawah litupan daun luruh (O Horizon) dan tanah atas (A Horizon –
tidak melebihi kedalaman 3cm) daripada dua lokasi berbeza. Pilih dari laman, kawasan
tumbuhan asli, aman,di bawah spesis pokok yang berbeza atau kawasan-kawasan lain.
Masukkan sampel-sampel ke dalam bag plastik, dimeterikan dan dilabelkan dengan nama anda
dan lokasi kutipan. Pada setiap lokasi, rekodkan jenis tanaman pada lokasi (contoh, hutan,
paya, laman dan lain-lain) dan ciri- ciri dalam jadual di bawah, kemudian gunakan untuk
membandingkan habitat tanah dari dua lokasi. Jika anda tidak mempunyai peralatan yang cukup
(contoh: pH kit atau penetrometer), buang ciri tersebut.
Ciri-ciri Lokasi Lokasi 1 Lokasi 2
Jenis tanaman
tahap naungan
Kelembapan/Kekeringan
Tanah
pH Tanah
Kemampatan Tanah
Tekstur Tanah (pasir, liat
dll)
Jadual 1
Kembali ke makmal, campurkan sampel tanah dengan tanah litupan daun dari lokasi yang
sama. Masukkan satu sampel yang diketahui ke dalam corong Tulgren. Biarkan selama 2 hari,
kemudian tuangkan kedalam piring petri yang mengandungi alkohol. Masukkan sampel dari
lokasi kedua ke dalam corong Tulgren dan tuangkan selepas 2 hari, mengikut prosedur yang
sama. Jika anda tahuisipadu tanah yang dikaji, anda akan boleh membandingkan kehadiran
makrofauna antara dua lokasi.
Jenis-jenis
corong Tulgren untuk mengekstrak fauna tanah
Daripada beg-beg sampel , periksa sampel tanah dari O Horizon dan A Horizon
dengan menggunakan microskope atau kanta tangan. Masukkan sebarang fauna
yang dijumpai ke dalam piring petri untuk dikenalpasti. Kenalpasti semua organisma
dan kelaskan kedalam kumpulan yang berlainan (contoh: Kumpulan A tiada kaki –
cacing; kumpulan B 8 kaki – laba-laba, hama dan lain-lain). Kira jumlah individu dalam
setiap kumpulan. Jika terlalu banyak, anggarkan jumlah yang sepatutnya.
a. Makrofauna Terbesar
Order atau Kumpulan
Makrofauna
Bilangan @ lokasi 1
isipadu tanah = ____
Bilangan @ lokasi 2
isipadu tanah = ____
Jadual 2
Kosongkan kandungan dalam jar pengumpul ke dalam piring petri, dan kenal pasti
dalam kumpulan. Kira jumlah individu dari setiap kumpulan.
b. Makrofauna terkecil
Order atau Kumpulan
Makrofauna
Bilangan @ lokasi 1
isipadu tanah = ____
Bilangan @ lokasi 2
isipadu tanah = ____
Jadual 3
Guna keputusan dari Jadual 2 dan 3 dan kira bilangan order atau kumpulan seliter
tanah dan litupan daun, dan bilangan individu dari setiap order atau kumpulan seliter
tanah dan litupan daun.
Makrofauna lokasi 1
lokasi 2
bilangan Order atau kumpulan seliter tanah/litupan
contoh: bil individu kum. B seliter tanah/litupan
15 7
bil. individu seliter tanah/litupan
bil. individu seliter tanah/litupan
Laporan Anda – Menerangkan peranan biota tanah
Laporan anda mestilah mengandungi tajuk, pendahuluan yang menerangkan tentang amali
tersebut, dan satu penerangan tentang perbincangan (lebih kurang 600 patah perkataan)
berdasarkan soalan-soalan berikut. Anda juga mesti memasukkan satu jadual ringkasan bagi
menunjukkan keputusan anda. Laporan ini ditulis secara soalan dan jawapan tetapi rujukannya
hendaklah tepat dan betul.
1. Bagaimanakah kepelbagaian makrofauna tanah dari dua lokasi berbeza?
Bolehkah anda cadangkan kenapa terjadinya perbezaan antara mereka.
Apakah parameter yang anda ukur yang boleh membantu anda untuk
menerangkan perbezaan- perbezaan tersebut?
2. Terangkan peranan makrofauna dalam tanah tersebut.
3. Pada rajah jaringan makanan yang disediakan, labelkan jenis-jenis biota
(contohnya,fungi, nematod dan lain-lain), apa yang mereka lakukan
(pemangsa, pemakan daun dll) dan huraikan bagaimana arah aliran tenaga
berlaku. Contoh, dimanakah bermulanya pembentukan tanaga dan dimanakah ianya
berakhir (puncak rantai makanan).
Apakah akan terjadi kepada tenaga dan nutrien apabila organisma pada
puncak rantai makanan mati?
Sertakan rajah ini dengan laporan anda.
Soil biota and invasive plants
Kurt O. Reinhart1,
Ragan M. Callaway2
Abstract
Top of page
Abstract
I. Introduction
II. Soil community effects
III. Soil-borne antagonists
IV. Soil-borne mutualists
V. Conclusion
Acknowledgements
References
Contents
Summary 445
I
Introduction 446
II
Soil community effects 446
III
Soil-borne antagonists 451
IV
Soil-borne mutualists 452
V
Conclusion 454
Acknowledgements 454
References 454
Summary
Interactions between plants and soil biota resist invasion by some nonnative plants and facilitate
others. In this review, we organize research and ideas about the role of soil biota as drivers of
invasion by nonnative plants and how soil biota may fit into hypotheses proposed for invasive
success. For example, some invasive species benefit from being introduced into regions of the
world where they encounter fewer soil-borne enemies than in their native ranges. Other
invasives encounter novel but strong soil mutualists which enhance their invasive success.
Leaving below-ground natural enemies behind or encountering strong mutualists can enhance
invasions, but indigenous enemies in soils or the absence of key soil mutualists can help native
communities resist invasions. Furthermore, inhibitory and beneficial effects of soil biota on plants
can accelerate or decelerate over time depending on the net effect of accumulating pathogenic
and mutualistic soil organisms. These ‘feedback’ relationships may alter plant–soil biota
interactions in ways that may facilitate invasion and inhibit re-establishment by native species.
Although soil biota affect nonnative plant invasions in many different ways, research on the topic
is broadening our understanding of why invasive plants can be so astoundingly successful and
expanding our perspectives on the drivers of natural community organization.
I. Introduction
Top of page
Abstract
I. Introduction
II. Soil community effects
Jump to…
III. Soil-borne antagonists
IV. Soil-borne mutualists
V. Conclusion
Acknowledgements
References
Most naturalized nonnative species appear to behave ecologically more or less like resident
species, and occur at low to mid frequencies (Huston, 1994; Williamson & Fitter,
1996; Davis et al., 2000 ; Brown & Peet, 2003). However, a small proportion of introduced
nonnative species become locally dominant (Levine et al., 2003 , and citations therein) and
change relatively diverse communities into near monocultures. These species are generally
referred to as ‘invasive’ (Colautti & MacIsaac, 2004). This transformation of communities
indicates that very powerful, but poorly understood, ecological phenomena are at work. Interest
in the causes and effects of invasions has prompted the development of a number of
nonmutually exclusive hypotheses to explain invasions including: enemy release, the evolution
of novel traits, disturbance, novel biochemical weapons, and empty niches in invaded
communities (Macket al., 2000 ; Hierro et al., 2005 ). Rapidly accumulating research has
connected soil organisms to these hypotheses and indicates that they may have powerful effects
on invasions. Here, we have organized research and ideas about the role of soil biota as drivers
of invasion by nonnative plants and how the effects of soil biota on invasives may expand the
general hypotheses that have been proposed for invasive success. In this context, we have
organized this review into three sections: II, Soil community effects; III, Soil-borne antagonists;
and IV, Soil-borne mutualists. Section II, Soil community effects, treats soil communities as a
‘black box’ while sections III, Soil-borne antagonists (i.e. nematodes and pathogens), and IV,
Soil-borne mutualists (i.e. mycorrhizas and nitrogen fixers), attempt to dissect some components
of the ‘black box’ and partition biological interactions into two distinct functional groups. Our
groupings of organisms by their biotic interactions are broad generalizations used for
organizational clarity (e.g. most mycorrhizas are classified as mutualists). However, it is
important to clearly acknowledge that the effects of some individual species are counter to our
classification (e.g. mycorrhizas can act as parasites instead of mutualists).