Remember this thing? Hopefully every biocrust enthusiast has one on their shelves. Mine is signed by Jayne, and I need to remember to bring it to Spain to collect autographs of Otto Lange and all the other contributors. Of course there were plenty of seminal papers and some pretty good reviews before, but this book (1st edition 2001) has become such a valuable one stop shopping source for crust information that many people have taken to referring to it as the crust bible.
Well, alot has happened since this publication. First, there's just more biocrust researchers which has alot to do with the publication of the crust bible. The subject matter of crust research has changed, for example we are now seeing biocrusts used as model organisms in ecology and more and more climate change research, and we are seeing more and more work on ecological restoration. The geography of the biocrust research community has shifted also. At the time this book was written, biocrust researchers were primarily based in the US, Germany, Israel, and Australia. Now, I think its fair to say that China accounts for at least half if not more of the biocrust research production. Also the emergence of biocrust research in Spain has also been impactful, and a sizable group based in France is also notable. Basically, many more people in many more places are contributing to the biocrust knowledge base. This is undeniably a good thing, but it means that the crust bible is a bit out of date. It needs and update, but more than that.....a sequel. A New Testament!
While there will be several contributors in common, the new book seems to be a bit of a youth movement. Some of the students of the original authors will contribute, in additional to several new contributors. Below is an outline as it stands now. I love the title. To me there seems to be a thinly veiled message:
this is an extremely important thing that most of you desert scientists are not noticing, look down once in a while (eyes rolling).
Ecological Studies
Biological Soil Crusts: An Organizing
Principle in Drylands
Ed. by B. Weber, B. Büdel and J.
Belnap
Table of Contents
Part I: Introduction
1 Biological soil crusts as a
critical zone of global importance (J. Belnap, <jayne_belnap@usgs.gov>)
In this chapter, the concept of biocrusts as the critical zone in drylands will be presented. As these
communities cover the soil surface in these regions, they mediate almost all
materials entering and leaving the soil, thereby influencing most ecosystem
processes including, hydrology, erosion protection, nutrient cycling, vascular
plant nutrition and community composition. Their role in ecosystem
services will be introduced in this opening chapter.
2 How biological soil crusts became studied as a
community (O.L. Lange, <ollange@botanik.uni-wuerzburg.de>)
In this chapter, Professor Lange will describe the
history of the first research on biocrusts:
the recognition of the organisms as a community, the people who studied them
and the techniques utilized.
Part II: Morphology,
composition, and distribution of biological soil crusts at different scales
3 Fossil crusts: (H. Beraldi, <hberaldi@unam.mx>)
Biological soil crusts and their components have been
identified as fossils from a wide range of rock types found in different parts
of the world. In this chapter, these fossil findings will be described and their
implications for the evolution of biocrusts and
their components will be discussed.
4 Cyanobacteria and algae within biological soil
crusts (B. Büdel, <buedel@rhrk.uni-kl.de>)
The diversity and functional roles of cyanobacteria
and algae within biocrusts of different (climatic)
regions will be described in this chapter. Reasons for variation and stability
of taxonomic composition, as well as present and future determination methods
will be discussed.
5 Fungi and bacteria within
biological soil crusts (M. Grube, <martin.grube@uni-graz.at>)
Description of the diversity and functional roles of
fungi and bacteria within biocrusts of different types and (climatic) regions. Present
and future methods of determination methods will be discussed.
6 Bryophytes within biological soil crusts (H. Kürschner,
<kuersch@zedat.fu-berlin.de>)
The diversity and functional roles of biocrust bryophytes
in different habitats (soils, climate, vegetation type) will be described in
this chapter. Advantages of a molecular approach in bryophyte identification
will be discussed.
7 Lichens within biological soil crusts (M.
Westberg, <Martin.Westberg@nrm.se>)
Description of the diversity and
functional roles of biocrust lichens from
different habitats (soils, climate, vegetation type). Advantages of molecular
as compared to classical morphological identifcation methods will be discussed.
8 Microfauna within biological soil crusts (B. Darby,
<brian.darby@UND.edu>)
Biocrusts are known to constitute an important habitat
for microfauna such as nematodes, collembola, mites, springtails and snails.
The diversity and potential functional roles of microfauna within biocrusts of
different habitats will be described in this chapter.
9 Composition and structure of biological soil
crusts (B. Büdel, <buedel@rhrk.uni-kl.de>)
The composition of biocrusts, comprising the organisms
described in chapters 5 to 9, is influenced by climatic, pedogenic and successional
parameters. This organism composition, but also macro- and microclimatic
conditions as well as landuse patterns are known to influence the external
morphology of biocrusts. The variation of biocrust
composition and morphology and the resulting effects on ecosystem function will
be described.
10 Controls on distribution patterns of
biological soil crusts at the micro-, macro-, and global scale (M.A. Bowker, <Matthew.Bowker@nau.edu>)
Distribution patterns of biological soil crusts are
determined by a variety of different abiotic factors, such as soil structure
and chemistry, vegetation, and climate conditions. Distribution patterns will
analyzed and described at different scales.
11 Long-term studies on different types of biological
soil crusts (J. Belnap, <jayne_belnap@usgs.gov>)
Biocrusts and their components have been monitored at
multiple sites for five to twenty years. Their
growth, distribution patterns, and response to climate and vegetation changes
give important insights into the long-term stability, development and structure
of biocrusts.
12 Remote sensing of biological soil
crusts at different scales (B. Weber, <b.weber@mpic.de>)
Imaging spectroscopy methods have been
utilized to classify biocrusts within different
types of remote sensing imagery. Aside from the classification of biocrusts
at the macroscale, imaging spectroscopy has been used
to differentiate between different types of biocrusts and also different land use intensities have been
differentiated by means of remote sensing techniques.
Part III: Functional
roles of biological soil crusts
13 Microstructure and weathering
processes within biological soil crusts (F. Garcia-Pichel, <ferran@asu.edu>)
Biological soil crust organisms
have been shown to influence the microstructure of the soil and cause
weathering processes within the upper soil matrix. These processes, depending
on the type of biocrust organisms present, as well as the initial soil
composition and structure, will be described in this chapter.
14 Nitrogen cycling of biological
soil crusts at micro- macro-, and global scales (N. Barger, <Nichole.Barger@Colorado.EDU>)
Many cyanobacteria and cyanobacterial
lichens in biocrusts fix atmospheric
nitrogen. This newly fixed nitrogen has three pathways: some is nitrified or denitrified
within the biological soil crust, some is leached into underlying soils, and a
third part is released into the atmosphere as NO and N2O. The
different sinks of biocrusts have been shown to
differ among them, depending on the N-content of the soil, temperature, soil
texture and water status. New studies at the global, ecosystem and micro-scales
will be presented. Future research methods and questions regarding this highly
relevant field of research will also be analyzed.
15 Carbon budgets of biological soil
crusts at micro- macro-, and global scales (L. Sancho, <sancholg@farm.ucm.es>)
During the last few years there have been
several long-term studies determining the C-budget of biocrusts
at the micro- and the mesoscale. These investigations
have been conducted at sites within different climatic regions and on several
continents. Synthesizing these data promises a big step towards more precise calculations
of long-term nutrient fluxes. Apart from these field studies, a global
modelling analysis of C-fixation accomplished by biocrusts will be presented in this chapter.
16 Biological soil crusts as soil stabilizers
(J. Belnap, <jayne_belnap@usgs.gov>)
Where the biomass of biocrusts
is sufficient, they stabilize soils, decreasing both
wind and water erosion. They also capture dust, which contains nutrients. Thus,
in addition to fixing nitrogen (Chap 14) and carbon (Chap 15) they influence
soil fertility in other ways
17 Effects of biological soil crusts
on arid land hydrology (S. Chamizo, <scd394@ual.es>)
Biological soil crusts are well-known to affect soil
hydrology of arid lands in a complex and non-uniform manner. The effect of biocrusts
on infiltration and runoff appear dependent on crust composition, external
morphology, soils, site characteristics (e.g., slope), vegetative cover, and
macroclimatic conditions. During the last decade, there have been many new
insights, which will be presented here.
18 Response of biological soil crust organisms to
light, temperature, and water conditions (T.G.A. Green, <greentga@waikato.ac.nz>)
Biocrusts consist of poikilohydric
organisms, which passively outlast dry conditions to resurrect again upon
favourable water conditions. During the last years they have been shown to
adapt to varying light, water and temperature conditions within their
environment. Their ability to adapt seems to depend on the overall plasticity
of individual crust organisms. The great variability in adaptation potential of
different crust organisms will be discussed here.
Part IV: Interactions
between biological soil crusts and vascular plants
19 Interactions of biological soil
crusts with vascular plants (Y. Zhang, <zhangym@ms.xjb.ac.cn>)
Whereas a nutrient transfer between biocrusts
and vascular plants has been assumed in many studies,
evidence proving this has only recently been obtained. Several studies have now
shown that both C and N can be moved from biocrusts to plants and from plants to biocrusts via fungal hyphae.
Aside from this nutrient transfer, biocrusts
have been shown to affect seed retention, germination
and plant emergence of vascular plants. Plants adapted to biological soil crust
habitats were observed to have smooth seeds (thus lacking appendages), which may
facilitate their ability to slip into cracks in the biocrusts. Thus, biological soil crusts have a profound impact on
plant structure and communities within arid environments.
20 Biological soil crusts as
model to study plant interactions and functional roles (F. Maestre, <fernando.maestre@urjc.es>)
In this chapter, the authors explore how
biocrusts of deserts and many other ecosystems may serve as a useful model
system for studying multiple questions of interest in community and ecosystem
ecology, including biodiversity-ecosystem function relationships, the interplay
between positive and negative interactions along environmental gradients, the
source-sink hydrological dynamics in drylands, and the role of attributes of
biotic communities as modulators of ecosystem responses to global environmental
change. To illustrate their views, they synthesize recent and ongoing studies. They
complete the synthesis of the studies conducted so far with recommendations for
promoting the use of biocrusts by community and ecosystem ecologists, and with
a list of priorities for future research on this topic.
Part V: Threats to
biological soil crusts
21 Effects of surface disturbance on
biological soil crusts (E. Zaady, <zaadye@volcani.agri.gov.il>)
Surface disturbances (e.g., mechanical
disturbance, herbicides, fire) all can have severe effects on biological
soil crust composition and its physiological activity.
Studies of these effects will be discussed in this chapter.
Herbicides, functioning as photosynthesis
inhibitors, have been shown to kill cyanobacteria and soil algae, resulting in
a decrease in polysaccharide production and biomass. This, in turn, can lead to a reduction in
organic matter and increased soil and nutrient loss through erosion. The
detrimental effects of herbicides on biocrusts will be investigated on different time-scales within this chapter.
22 Effects of climate change on biological soil
crusts (S. Reed, <screed@usgs.gov>)
The effects of climate change on biological soil crusts
are expected to be complex. An increase in
temperature will reduce soil moisture, especially at the soil surface. Future
changes in precipitation amount and patterns will vary between different
regions. In areas with fewer precipitation events and lower total amounts of
rainfall, biological soil crust coverage is expected to decrease and
composition is predicted to shift towards more early-successional biocrust
types. As most processes (e.g., nitrogen and carbon fixation) are temperature
and moisture dependent, these will be affected as well. On the other hand, arid
and semi-arid regions are known to expand and the increased melting rate of
glaciers exposes bare soil surfaces, which serve as an ideal habitat for biocrusts
to colonize. Thus, the effects of climate change on biocrusts
are expected to be variable.
Part VI: Natural
and Enhanced Recovery and Management
23 Natural recovery of biological
soil crusts after disturbance (B. Weber, <b.weber@mpic.de>)
Natural recovery of biological soil crusts
after disturbance has been studied both in descriptive and experimental studies.
Whereas many investigations have shown that biocrusts need decades, if not centuries, to completely recover after
disturbance, other studies reveal that biocrusts show significant recovery after only a few years. In this chapter, we
will examine the data to find the factors (e.g., crust composition, soil,
climate, disturbance type) that predict recovery rates.
24 Enhanced recovery of biological soil crusts
after disturbance (Y. Zhao, <zyunge@ms.iswc.ac.cn>)
Different methods to enhance biological
soil crust recovery after disturbance have been experimentally investigated. These
have included stabilization of the soil surface with polyacrylamide gels, inoculation
of disturbed sites with cyanobacterial cultures or field-collected material,
and shade structures. These efforts have been differentially successful, and
factors leading to success will be discussed.
Part VII: Future
Research on biological soil crusts
25 Synthesis on biological soil
crust research (B. Weber, <b.weber@mpic.de>)
In the final synthesis chapter, we will
summarize the essential new findings regarding the different topics of biocrusts.
Additionally, we will identify knowledge gaps and promising new fields of research.
We will call for unified approaches to biocrust research and linking of researchers
and sites in order to answer pressing questions.
