Demography, Wild Harvest Patterns and Trade of Culturally Important Species: Priorities for Management and Conservation
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DEMOGRAPHY, WILD HARVEST PATTERNS AND TRADE OF CULTURALLY IMPORTANT SPECIES: PRIORITIES FOR MANAGEMENT AND CONSERVATION A DISSERTATION SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI‘I AT MĀNOA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN BOTANY December 2014 By Daniela Dutra Elliott DISSERTATION COMMITTEE: Tamara Ticktin, Chairperson David Duffy Thomas Ranker Lyndon Wester Demetria Mondragon i © 2014 Daniela Dutra Elliott i ABSTRACT We know very little about the impacts of harvest on populations of epiphytic plants, the species that depend on them on the canopy, and their ecosystems. The impacts of orchid collecting depend on the life history of the species, the type of collecting being conducted, and socioeconomic factors surrounding communities. In this dissertation, I detail the population biology, structure, and dynamics of populations for orchid species. In addition, I assess the cultural and socioeconomic patterns that influence harvest in order to fill knowledge gaps on tropical orchid species as well as to provide accurate metrics for the development of sustainable management plans in areas where overharvest is likely to occur. I documented the cultural and socioeconomic patterns of epiphyte use and trade in a market setting. Market studies can provide information of what is happening over a wide range of environments across long distances offering valuable information for conservation. I documented 19 species being sold in the market and a high volume of orchids being traded. There was a clear seasonal trend for orchid sales with two seasons identified. There was a strong cultural component to harvest with plants being part of major cultural and religious celebrations. I also documented that different orchid species are harvested using different methods. The type of harvest that was documented here offers valuable information on what is happening in the natural populations. In the demographic study, the projected population growth rate (λ) for P. karwinskii differed among the three study populations and this is likely due to differences in harvest pressure. Populations of P. karwinskii that experience high-medium harvest ii pressures are declining and are expected to continue to decline if circumstances do not change. By contrast, the population that has the lowest harvest pressure is projected to continue to grow slowly over the long term (λ is significantly greater than 1). My results suggest that sustainable harvest can be possible if less than 30% of flowering pseudobulbs are harvested per year from large adult plants in a population. However, this assumes harvest from only the adult plants (the largest pseudobulb > 19 cm) and not from any of the smaller sizes, even if they flower. A ban on orchid harvest on the national level has clearly not stopped the harvest of wild orchid species. The high volume of orchids traded combined with the available literature on orchid demography related to harvest suggests that harvest at those levels documented here is not likely sustainable. However, results suggest that lower levels may be sustainable, and that this could be achieved if communities had rights to harvest and therefore an investment in the future. Wild orchid harvest could be complemented with propagation as seen in bromeliads. In addition, a change of climate, land-use, or other factors should also be taken into consideration when applying these results to management in the future. iii TABLE OF CONTENTS ABSTRACT ............................................................................................................ ii CHAPTER 1: INTRODUCTION ........................................................................... 7 CHAPTER 2: PLANTS AS NTFPS FROM THE FOREST CANOPIES ........... 11 Abstract ............................................................................................................. 12 Introduction ....................................................................................................... 13 CHAPTER 3: WILD HARVEST PATTERNS AND TRADE ............................ 23 Abstract ............................................................................................................. 24 Introduction ....................................................................................................... 25 Materials and Methods ...................................................................................... 28 Results ............................................................................................................... 30 Discussion ......................................................................................................... 37 CHAPTER 4: DEMOGRAPHY AND HARVEST EFFECTS ............................ 42 Abstract ............................................................................................................. 43 Introduction ....................................................................................................... 44 Materials and Methods ...................................................................................... 45 Results ............................................................................................................... 51 Discussion ......................................................................................................... 60 CHAPTER 5: CONSERVATION RECOMENDATIONS .................................. 63 REFERENCES ..................................................................................................... 68 iv LIST OF TABLES Table 1: Data Collected using semi-structured interviews with wild orchid vendors. ............................... 30 Table 2: Wild orchid species information, price and total plant volume found in the Abastos Market ..... 33 Table 3: Origin information of orchid species sold in the market. ............................................................. 34 Table 4: Sample sizes and harvest pressure in P. karwinskii populations .................................................. 47 Table 5: Size class categories used to create matrix models. ...................................................................... 49 Table 6: Transient analysis results for P. karwinskii populations. .............................................................. 55 5 LIST OF FIGURES Figure 1: Study site in the State of Oaxaca. ................................................................................................ 29 Figure 2: Orchid vendors at the Abastos market in Oaxaca City. ............................................................... 32 Figure 3: Orchids specimens found at Abastos market.. ............................................................................. 35 Figure 4: Volume of orchid species sold in Abastos market, Oaxaca.. ....................................................... 36 Figure 5: Temporal variation in sales of five most traded orchid species ................................................... 37 Figure 6: Life history stages of Prosthechea karwinskii. ............................................................................ 49 Figure 7: Structure of the epiphytic orchid, P. karwinskii in three populations. ........................................ 52 Figure 8: Lambda values for populations of Prosthechea karwinskii. ........................................................ 53 Figure 9: Stochastic lambda values for populations of Prosthechea karwinskii. ........................................ 54 Figure 10: Elasticity values for Prosthechea karwinskii.. ........................................................................... 56 Figure 11: Life Table Response Experiment analyses for populations of Prosthechea karwinskii.. .......... 58 Figure 12: Simulated effects of a) flower harvest and b) flower and pseudobulb harvest. ......................... 59 6 CHAPTER 1 INTRODUCTION Daniela Dutra Elliott Department of Botany University of Hawai‘i at Manoa 3190 Maile Way Honolulu, HI 96822 7 In order to develop effective conservation plans for species and ecosystems, one must look at the complete picture and also understand the different components that will influence outcomes. Worldwide, a wide range of plants are harvested for their economic and cultural value (Cunningham, 2001; FAO, 1995), yet little is known about the impacts of harvest on populations of vascular and non-vascular epiphytic plants, the canopy species that depend on them, and their ecosystems. The potential for over-harvesting has generated concerns as a threat to species conservation and conservationists worldwide have sounded the alarm bells on plant trade for the past decades blaming in certain instances the disappearance of species on collectors (Koopowitz 2001; Flores-Palacios & Valencia-Díaz 2007; Mondragón 2009). The Convention on International of Endangered Flora and Fauna (CITES) has imposed international regulations in the trade of many species. For example, the entire orchid family is under CITES regulation. However, very few peer-review studies have documented the harvest or orchid species and looked at the different parts of the issue (Flores-Palacios & Valencia-Díaz 2007; Wolf & Konings 2001; Mondragón 2008; Mondragón 2009; Mondragón & Ticktin 2011; Peck & Christy 2006; Peck & Frelich 2008; Peck & Muir 2007; Molleman et al. 2011). Some of these components are: 1. Market trends: Who is buying, who is selling, how much, how many species? 2. Traditional Ecological Knowledge and cultural practices related to orchid species: