Fates of Trees and Forests in Boliva Subjected to Selective Logging, Fire, and Climate Change

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Material Information

Title:
Fates of Trees and Forests in Boliva Subjected to Selective Logging, Fire, and Climate Change
Physical Description:
1 online resource (159 p.)
Language:
english
Creator:
Shenkin, Alexander F
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Interdisciplinary Ecology
Committee Chair:
PUTZ,FRANCIS E
Committee Co-Chair:
BARNES,GRENVILLE
Committee Members:
BOLKER,BENJAMIN MICHAEL
PONCIANO CASTELLANOS,JOSE MIGUEL

Subjects

Subjects / Keywords:
biomass -- damage -- drought -- forest -- logging -- tropical
Interdisciplinary Ecology -- Dissertations, Academic -- UF
Genre:
Interdisciplinary Ecology thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Tropical forests are under siege, but more attention is paid to their total removal (i.e., deforestation) than to their degradation(i.e., loss of values without loss of forest). Here the focus in on forests degraded by logging and fires, coupled with the less obvious impacts of climate change. I evaluated the impacts of these factors and their interactions on tree mortality, growth, and species composition in a transitional tropical forest in Eastern Bolivia.  To understand how this forest responds to the direct impacts of controlled selective logging,  evaluated the patterns and rates of stand recovery in logging gaps and the fates of trees damaged by timber harvests. To understand the effects of logging on carbon dynamics, I surveyed 60 logging gaps 8-9 years after reduced-impact logging.  I found that newly-recruited trees in large gaps are less likely to be liana-infested than those in small gaps, and that trees on gap borders grew 0.15 cm/year more rapidly in diameter and harbored fewer lianas than trees away from gaps. Also, new recruits contributed more biomass to the recovery of large than small gaps. Finally, tree biomass in gaps was not detectably related to the proximity of other gaps. Logging, drought, and fire as well as their interactions all influenced tree species assembly and forest structure over a 7-yearobservation period.  Models of tree mortality and growth in response to these forces revealed that logging shifts tree species composition into assemblages that should be more tolerant of future droughts. This shift was evident in the increased survival rates of seedlings of drought-tolerant tree species but might be counter-balanced by the observed higher mortality rates of trees >10 cm DBH of species characteristic of relatively dry forests. While species composition shifted towards drought tolerance, forest structure did not: large trees in this forest suffered disproportionally from droughts.  Increased vulnerability to droughts was more closely related to crown exposure than to DBH. Finally, to clarify one longer-term impact of selective logging, I tracked the fates of trees damaged during the harvest for up to 8years afterwards.  While damaged trees initially suffered elevated mortality rates, those that survived 8 years after being damaged then exhibited similar mortality rates to undamaged trees. Over that same period, trees with damaged roots suffered particularly high mortality rates and trees with damaged crowns grew very slowly. Taken together, these studies illustrate that the while responses of tropical forests to disturbance and stress are complex, some factors standout as particularly important.  Large trees suffer disproportionally from drought and while logging may favor seedlings of drought-tolerant species, larger trees characteristic of dry forests may not endure droughts better than those from wetter forests.  While mitigating climate change, improved forest management interventions such as liana cutting may enable forests to recoup carbon emissions from logging quickly.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Alexander F Shenkin.
Thesis:
Thesis (Ph.D.)--University of Florida, 2014.
Local:
Adviser: PUTZ,FRANCIS E.
Local:
Co-adviser: BARNES,GRENVILLE.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2014-11-30

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0045865:00001