Whitworth, Andrew William (2016) Conservation value, biodiversity value and methods of ...

364 Pages·2016·10.15 MB·English

Whitworth, Andrew William (2016) Conservation value, biodiversity
value and methods of assessment in regenerating and human disturbed
tropical forest. PhD thesis.

http://theses.gla.ac.uk/7426/

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Glasgow Theses Service
http://theses.gla.ac.uk/
[email protected]
Conservation Value, Biodiversity Value
and Methods of Assessment in
Regenerating and Human Disturbed
Tropical Forest

Andrew William Whitworth
MSc Conservation Biology (distinction) – Manchester Metropolitan University
BSc Zoology (Hons) – The University of Leeds

A thesis submitted in partial fulfilment of the requirements for the
degree of doctor of philosophy.

The Institute of Biodiversity, Animal Health and Comparative Medicine,
The College of Medical, Veterinary & Life Sciences,
The University of Glasgow.

Supervisors: Dr Ross MacLeod and Prof. Roger Downie

June 2016
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―Uniformity is not nature’s way; diversity is nature’s way.‖
Vandana Shiva
2

Thesis Abstract
Although the value of primary forests for biodiversity conservation is well
known, the potential biodiversity and conservation value of regenerating forests
remains controversial. Many factors likely contribute to this, including: 1. the
variable ages of regenerating forests being studied (often dominated by
relatively young regenerating forests); 2. the potential for confounding on-going
human disturbance (such as logging and hunting); 3. the relatively low number of
multi-taxa studies; 4. the lack of studies that directly compare different historic
disturbances within the same location; 5. contrasting patterns from different
survey methodologies and the paucity of knowledge on the impacts across
different vertical levels of rainforest biodiversity (often due to a lack of suitable
methodologies available to assess them). We also know relatively little as to how
biodiversity is affected by major current impacts, such as unmarked rainforest
roads, which contribute to this degradation of habitat and fragmentation. This
thesis explores the potential biodiversity value of regenerating rainforests under
the best of scenarios and seeks to understand more about the impact of current
human disturbance to biodiversity; data comes from case studies from the Manu
and Sumaco Biosphere Reserves in the Western Amazon.
Specifically, I compare overall biodiversity and conservation value of a best case
regenerating rainforest site with a selection of well-studied primary forest sites
and with predicted species lists for the region; including a focus on species of
key conservation concern. I then investigate the biodiversity of the same study
site in reference to different types of historic anthropogenic disturbance.
Following this I investigate the impacts to biodiversity from an unmarked
rainforest road. In order to understand more about the differential effects of
habitat disturbance on arboreal diversity I directly assess how patterns of
butterfly biodiversity vary between three vertical strata. Although assessments
within the canopy have been made for birds, invertebrates and bats, very few
studies have successfully targeted arboreal mammals. I therefore investigate the
potential of camera traps for inventorying arboreal mammal species in
comparison with traditional methodologies. Finally, in order to investigate the
possibility that different survey methodologies might identify different
biodiversity patterns in habitat disturbance assessments, I investigate whether
two different but commonly used survey methodologies used to assess
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amphibians, indicate the same or different responses of amphibian biodiversity
to historic habitat change by people.
The regenerating rainforest study site contained high levels of species richness;
both in terms of alpha diversity found in nearby primary forest areas (87% ±3.5)
and in terms of predicted primary forest diversity from the region (83% ±6.7).
This included 89% (39 out of 44) of the species of high conservation concern
predicted for the Manu region. Faunal species richness in once completely
cleared regenerating forest was on average 13% (±9.8) lower than historically
selectively logged forest. The presence of the small unmarked road significantly
altered levels of faunal biodiversity for three taxa, up to and potentially beyond
350m into the forest interior. Most notably, the impact on biodiversity extended
to at least 32% of the whole reserve area. The assessment of butterflies across
strata showed that different vertical zones within the same rainforest responded
differently in areas with different historic human disturbance. A comparison
between forest regenerating after selective logging and forest regenerating after
complete clearance, showed that there was a 17% greater reduction in canopy
species richness in the historically cleared forest compared with the terrestrial
community. Comparing arboreal camera traps with traditional ground-based
techniques suggests that camera traps are an effective tool for inventorying
secretive arboreal rainforest mammal communities and detect a higher number
of cryptic species. Finally, the two survey methodologies used to assess
amphibian communities identified contrasting biodiversity patterns in a human
modified rainforest; one indicated biodiversity differences between forests with
different human disturbance histories, whereas the other suggested no
differences between forest disturbance types.
Overall, in this thesis I find that the conservation and biodiversity value of
regenerating and human disturbed tropical forest can potentially contribute to
rainforest biodiversity conservation, particularly in the best of circumstances. I
also highlight the importance of utilising appropriate study methodologies that
to investigate these three-dimensional habitats, and contribute to the
development of methodologies to do so. However, care should be taken when
using different survey methodologies, which can provide contrasting biodiversity
patterns in response to human disturbance.
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Contents
Thesis Abstract ................................................................................................................................. 2
Thesis Organisation .......................................................................................................................... 7
List of Figures .................................................................................................................................. 9
List of Tables ................................................................................................................................. 13
Acknowledgements ........................................................................................................................ 15
General Introduction ..................................................................................................................... 18
What is biodiversity?..................................................................................................................... 18
Outside of conservation, why does biodiversity matter to people? ............................................ 18
How fast is biodiversity being lost, and why? ............................................................................... 20
Why are tropical forests so important for biodiversity? and how fast are they being lost and
degraded? ..................................................................................................................................... 22
What are the greatest threats to tropical forest biodiversity? ..................................................... 23
Regenerating landscapes and their biodiversity and conservation value .................................... 25
Roads a major cause of degradation to tropical forests ............................................................... 27
Understanding the canopy............................................................................................................ 28
The importance of understanding the results of different survey methodologies ...................... 28
Thesis study areas ......................................................................................................................... 29
The importance but lack of multi-taxa research ........................................................................... 30
Survey groups within this study .................................................................................................... 31

Chapter 1 - How much potential biodiversity and conservation value can a regenerating
rainforest provide? A site-level, comparative species list approach to infer the value of
local reserves for conservation. .................................................................................................. 34
Authors and contributions ............................................................................................................ 34
Abstract ......................................................................................................................................... 35
Introduction .................................................................................................................................. 36
Methods ........................................................................................................................................ 40
Results ........................................................................................................................................... 48
Discussion...................................................................................................................................... 52
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Chapter 2 - Long lasting impressions: After decades of regeneration, rainforest
biodiversity remains differentially affected following varied human disturbances; but
has high potential conservation value. ...................................................................................... 59
Authors and contributions ............................................................................................................ 59
Abstract ......................................................................................................................................... 60
Introduction .................................................................................................................................. 61
Methods ........................................................................................................................................ 64
Results ........................................................................................................................................... 76
Discussion...................................................................................................................................... 91

Chapter 3 – The response of faunal biodiversity to an unmarked road in the Western
Amazon. ........................................................................................................................................... 96
Authors and contributions ............................................................................................................ 96
Abstract ......................................................................................................................................... 97
Introduction .................................................................................................................................. 98
Methods ...................................................................................................................................... 100
Results ......................................................................................................................................... 104
Discussion.................................................................................................................................... 109

Chapter 4 - Past human disturbance effects upon biodiversity are greatest in the
canopy; a case study on rainforest butterflies. ...................................................................... 113
Authors and contributions .......................................................................................................... 113
Abstract ....................................................................................................................................... 114
Introduction ................................................................................................................................ 115
Methods ...................................................................................................................................... 118
Results ......................................................................................................................................... 127
Discussion.................................................................................................................................... 141
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Chapter 5 - Out on a limb: Arboreal camera traps as an emerging methodology for
inventorying elusive rainforest mammals. .............................................................................. 147
Authors and contributions .......................................................................................................... 147
Abstract ....................................................................................................................................... 148
Introduction ................................................................................................................................ 149
Methods ...................................................................................................................................... 151
Results ......................................................................................................................................... 155
Discussion.................................................................................................................................... 161

Chapter 6 - Methods matter: Different biodiversity survey methodologies identify
contrasting biodiversity patterns in a human modified rainforest. .................................... 164
Authors and contributions .......................................................................................................... 164
Abstract ....................................................................................................................................... 165
Introduction ................................................................................................................................ 166
Methods ...................................................................................................................................... 168
Results ......................................................................................................................................... 175
Discussion.................................................................................................................................... 182

Thesis Discussion .......................................................................................................................... 187
References – main data chapters .............................................................................................. 195

Appendix manuscript 1 - Herpetofaunal responses to anthropogenic habitat change
within a small forest reserve in Eastern Ecuador. ................................................................. 289
Appendix manuscript 2 – A first test of the thread bobbin tracking technique as a
method for studying the ecology of herpetofauna in a tropical rainforest. ..................... 314
Appendix manuscript 3 - Bamboo traps as refugia for Pristimantis olivaceus (Anura:
Craugastoridae) and as breeding site for Osteocephalus castaneicola (Anura: Hylidae)
........................................................................................................................................................ 338
Appendix manuscript 4 - Osteocephalus mimeticus (Melin, 1941) (Amphibia: Anura:
Hylidae): New locality, range extension and notes on distribution. .................................. 346
Appendix manuscript 5 - Doryfera johannae (Bourcier, 1847) (Aves: Apodiformes:
Trochilidae): New locality, range extension and notes on distribution. ............................ 354
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Thesis Organisation
This thesis is presented in the form of six main chapters, each of which has been
prepared for publication in the style of a stand-alone manuscript (including
introduction and discussion) suitable for submission to scientific journals in the
fields of ecology and conservation. Presentation as manuscripts does mean that
some information, particularly in methods, is repeated more than once, but this
should make each chapter of the thesis more readable without a constant need
to refer back to other chapters.
1) Chapter one assesses the overall biodiversity and conservation value of a
regenerating rainforest site from the Amazon region of SE Peru. The
chapter compares the values of this regenerating study site with the
biodiversity found at a selection of well-studied primary forest sites and
the predicted species list for the region. In addition it focuses upon key
indicator species and species of key conservation concern.
2) The second chapter investigates the biodiversity within a regenerating
forest once subjected to different types of historic anthropogenic
disturbance. This is achieved through a multi-taxa analysis including data
on amphibians, butterflies, birds and mammals.
3) Chapter three assesses the ecological disruption to faunal biodiversity of
the presence of a small, unmarked Amazonian road; from the eastern
Amazon region of Ecuador. The study is multi-taxa, including an
assessment of amphibians, birds and butterflies.
4) Chapter four examines terrestrial and arboreal patterns of biodiversity
within a regenerating rainforest, focussing upon butterflies. Measures
include species richness, species diversity, community structure and
abundance.
5) The fifth chapter examines the efficiency and potential for the use of
arboreal camera traps in generating rapid inventories of arboreal
rainforest mammals; in comparison with traditional survey techniques.
The comparison includes both the effectiveness of data gathering and a
financial cost-benefit comparison.
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6) This final data chapter examines patterns of amphibian biodiversity, with
the aim to directly assess whether different survey methodologies provide
the same or contrasting patterns of biodiversity in response to different
forms of historic human disturbance; a potentially contributing factor
towards the controversy about the biodiversity value of regenerating
rainforest.

In addition to these six chapters, the thesis begins with a general introduction on
biodiversity and finishes with a short final discussion which brings together the
major findings and conclusions of the main chapters and assesses their overall
significance; with suggestions for future progression of research in this field.
Appendices that provide supporting materials for the data chapters are all
located at the very end of the thesis. In addition to the appendices for each of
the main chapters, the appendices contain five additional published or accepted
supporting papers on regenerating rainforest biodiversity and survey methods.
These demonstrate my ability to produce publication quality research on these
subjects. These relate to: 1. the effects of human habitat disturbance on
amphibian and reptile communities; 2. trialling bobbin tracking methodologies
for amphibians and reptiles, for the first time in a tropical rainforest; 3. the use
of bamboo traps as refugia for two poorly known species of rainforest
amphibians; 4. the first distribution map and range extension for a species of
frog of the genus, Osteocephalus; and 5. the first distribution map and range
extension of a species of hummingbird. These supporting papers were co-
authored, initiated and overseen by myself and their inclusion follows university
thesis guidelines. In the appendix I explain what my specific role and
involvement was for each paper, explain their relevance to the thesis and
provide the full citation for published versions. They are added into this section
to separate them from the papers/manuscripts on which I am the first author.