Reading

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).