Cycad Conservation Research Articles

Predicting habitat suitability for the Australian cycad-attacking weevil (Siraton internatus) under climate change

Cycads hold important economic and conservation value. Some species are extensively used in landscaping, while others are endangered and legally protected. The Australian cycad-attacking weevil, Siraton internatus, is notably destructive, occasionally causing infestations and invasions across various countries. This study simulated habitat suitability for S. internatus to assess its potential invasion and the impact of climate change. Habitat suitability was evaluated under current climate and four climate change scenarios over two time frames (2050 and 2090). Furthermore, we investigated the threat posed by S. internatus to cycad reserves, using Taiwanese reserves as a representative case. Our MaxEnt predictions demonstrated high accuracy, meeting multiple evaluation criteria. We explored the potential distribution of S. internatus within Australia and internationally, identifying suitable habitats in Africa, the Americas, Asia, and Europe. The case study highlighted the low habitat suitability within the two Taiwanese cycad reserves, which is projected to decrease to unsuitable levels under future climate change scenarios for this weevil species. Moreover, our results revealed that suitable habitat for S. internatus is projected to contract globally under all climate scenarios and time periods, but expansion in Chile and the southern Himalaya (e.g., Nepal). This study provides valuable insights into cycad conservation and pest invasion risks. The results support both global and local efforts to manage the invasion threats from this destructive Australian cycad-attacking weevil species. It also accentuates the urgency for continuous biosecurity inspections and prevention of exporting mature cycad caudexes from Australia.

Speciation and conservation genetic assessment of two endangered cycad species

AbstractUnderstanding the driving forces of speciation is a central question in evolutionary biology. Cycas bifida (Dyer) K. D. Hill and Cycas micholitzii Dyer are two morphologically similar Cycas (Cycadaceae) species with deeply pectinate megasporophylls and dichotomously divided leaflets. Geographically, they are isolated by the Red River Fault Zone (RRFZ), which acts as a biogeographical barrier for many Cycas species. In this study, we investigated the divergence, genetic diversity, genetic structure, and demographic history of C. bifida and C. micholitzii to uncover the speciation mechanisms for the two endangered species. Results revealed high historical gene flow but low contemporary gene flow between the two species, with a deep divergence occurring in the Late Miocene. The long‐term geographical isolation and ecological niche differentiation were identified as important factors in driving the divergence of the two species, supported by significant isolation by distance testing, barrier analysis, and niche consistency detection. Geographical isolation by the RRFZ played a pivotal role in facilitating their divergence by constraining gene flow. Conservation genetic analyses indicated high genetic diversity within both species, coupled with disparate responses to Pleistocene climate fluctuations: C. micholitzii experienced population expansion, while C. bifida displayed a mild bottleneck effect. To ensure the protection and long‐term sustainability of two threatened species, relevant conservation guidelines were proposed based on the assessment of their genetic diversity and structure. This study furnishes valuable insights into the mechanisms underpinning species divergence and delivers actionable recommendations for cycad conservation.

Cycad Regulation and Community Creation: South African Stakeholder Perspectives on Conservation

Cycads play a central role in Lobedu cultural mythology, with widespread acknowledgment of their cultural and spiritual values, as well as their instrumental use in rainmaking and coronation ceremonies. They are also widely prized as collectors’ items, both nationally and internationally, commanding high prices and placing them in the unenviable position of being among the world's most frequently trafficked plants. South African cycad species, most of which are endangered and all of which are protected, are heavily regulated, with the ownership, trade, and use of cycads requiring a permit. This article explores how regulations are understood by different stakeholders in cycad conservation. Traditional authorities, state institutions, and communities may collaborate in conservation, but also interpret and enact policies divergently. Processes of regulating cycad trade and propagation both reinforce and challenge certain aspects of community identity.

Poaching of Encephalartos transvenosus, in the Limpopo Province, South Africa

There is an established link between deforestation and negative hydrological effects which may affect watersheds. The number of the cycads Encephalartos transvenosus Stapf & Burtt Davy in South Africa is drastically reducing, and they are nearly extinct. Additionally, poaching and reduction in the population of cycads in reserves may impact negatively on watersheds in protected and buffer areas since the regeneration of this plant occurs over a long period. This research aimed to study the distributions of poached cycads, evaluate the factors responsible for poaching activity and suggest possible solutions towards conservation of E. transvenosus Stapf & Burtt Davy in some of the nature reserves in Limpopo province. Field observation was used to ascertain and collect locations of poached cycads. Data was obtained through the use of a questionnaire. Questionnaires were administered to rangers for the collection of data on causes of poaching, parts poached, measures taken and challenges of rangers in the nature reserves. Processing of the collected data was done by simple statistical analysis. The total population of rangers available in the reserves was used for the determination of the sample size of rangers by Slovin’s formula. Unemployment (46%) is the leading cause for poaching in Mphaphuli Nature Reserve, while trade is a leading factor in Modjadji and Lekgalameetse (37% and 60%) respectively. Debarked cycads amount to 14 (54%) while 12 of the total (26 poached cycads) were completely removed (46%). The most effective way of stopping the poaching of cycads as perceived by the rangers is by patrolling the nature reserves. The observed poaching of Encephalartos transvenosus is alarming since this plant has a low population size which is currently confined to the Limpopo Province in South Africa only. If poaching continues in the nature reserves, all cycads have the tendency of being removed. Therefore, there is a need to continually develop strategies for the conservation of cycads. The peculiar nature and challenges of each reserve have been established and unique solutions for these nature reserves in Limpopo Province have been proposed. Better conservation of cycad species can positively impact the hydrological process of the concerned area and better help the watersheds.

Localized Overabundance of an Otherwise Rare Butterfly Threatens Endangered Cycads

Though once considered extinct in Florida, the Eumaeus atala butterfly (Poey) (Lepidoptera: Lycaenidae) has made a slow but steady recovery thanks to grassroots conservation efforts targeting the butterfly and its only native foodplant, the cycad Zamia integrifolia L.f. (Cycadales: Zamiaceae). A robust E. atala population occurs at the Montgomery Botanical Center, a research and conservation facility in Coral Gables, Florida, USA, that cultivates a living collection of global cycads, many of which are critically endangered in the wild. Since the early 2000s, the E. atala population at the Montgomery Botanical Center has grown and adopted an expanded host range, much to the detriment of the plants; both native and exotic cycads incur consistent and severe damage from larval herbivory. This presents a complex situation in which in situ butterfly conservation conflicts with ex situ cycad conservation. Here we describe the local population of E. atala at the Montgomery Botanical Center, suggest testable hypotheses for explaining the butterfly's localized abundance, and discuss implications for butterfly and cycad conservation efforts in Florida.

Leaf Retention on Stem Cuttings of Two Zamia L. Species With or Without Anti-transpirants Does Not Improve Adventitious Root Formation

Improved horticultural practices may help to reduce demand for wild cycads threatened by unsustainable collection. We determined the influences of leaf retention with or without anti-transpirants on the success and speed of adventitious root development of Zamia furfuracea L.f. and Zamia integrifolia L.f. stem cuttings. Root formation success for both species was greater than 95%. The experimental treatments did not influence the percentage success or the speed of root development for Z. furfuracea or Z. integrifolia. The ending dry weights of the stems, leaves, and roots were also not influenced by the experimental treatments. Our results indicated that adventitious root formation on stem cuttings of these two Zamia species was highly successful with or without retained leaves, and horticultural application of transpiration-reducing products on retained leaves did not improve success. Our findings add to the growing body of evidence that show how the horticulture nursery industry can meet horticultural demands in an effort to stop wild harvesting of threatened plants. Conservation of cycads as a group would benefit from more horticulture studies such as this, especially if the research includes threatened species.

Ethnobotany of Mexican and northern Central American cycads (Zamiaceae)

BackgroundThis study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads in this region, and the need to improve cycad conservation strategies using ethnobotanical data. We hypothesized that cycads are significant dietary items with no long-term neurological effects, are important to religious practice, and contribute to cultural identity and sense of place, but that traditional knowledge and uses are rapidly eroding. Guiding questions focused on nomenclature, food and toxicity, relationships to palms and maize, land management issues, roles in religious ceremony, and medicinal uses, among others, and contributions of these to preservation of cycads.MethodsFrom 2000 to 2017, the authors conducted 411 semi-structured ethnographic interviews, engaged in participant-observation in Mexican and Honduran communities, and carried out archival research and literature surveys.ResultsWe documented 235 terms and associated uses that 28 ethnic groups have for 57 species in 19 languages across 21 Mexican states and 4 Central American nations. Carbohydrate-rich cycads have been both famine foods and staples for at least six millennia across the region and are still consumed in Mexico and Honduras. Certain parts are eaten without removing toxins, while seed and stem starches are detoxified via several complex processes. Leaves are incorporated into syncretic Roman Catholic-Mesoamerican religious ceremonies such as pilgrimages, Easter Week, and Day of the Dead. Cycads are often perceived as ancestors and protectors of maize, revealing a close relationship between both groups. Certain beliefs and practices give cycads prominent roles in conceptions of sense of place and cultural heritage.ConclusionsCycads are still used as foods in many places. Though they do not appear to cause long-term neurological damage, their health effects are not fully understood. They are often important to religion and contribute to cultural identity and sense of place. However, because most traditional knowledge and uses are rapidly eroding, new community-based biocultural conservation efforts are needed. These should incorporate tradition where possible and seek inspiration from existing successful cases in Honduras and Mexico.

Considering evolutionary processes in cycad conservation: identification of evolutionarily significant units within Dioon sonorense (Zamiaceae) in northwestern Mexico

Cycads are considered to be the most threatened plant group on Earth. Thus, the identification of important biological units for conservation is crucial for their management and protection. Taxonomic studies have enormously contributed to cycad conservation, since species descriptions formally recognize biodiversity components that can be considered in conservation. However, because multidisciplinary studies that evaluate the biodiversity within cycad species are almost non-existent intraspecific evolutionarily significant units (ESUs) have not been considered when making conservation plans. The cycad Dioon sonorense (Zamiaceae) has a relatively wide distribution range along a vegetation gradient in Northwest Mexico: the southern populations of D. sonorense occur in tropical forests, whereas the northern populations occur in more xeric environments in the Sonoran Desert. Although both habitats might have promoted important evolutionary trends within D. sonorense, only the southern populations are being conserved. Here, we evaluated whether intrinsic differentiation among populations of D. sonorense exists, and whether northern populations may merit attention in conservation programs. We analyzed the variation of genome-wide loci to evaluate the genetic structure among six populations. We found two clusters, northern and southern, that can be recognized using 361 neutral loci. Such genetic structure is consistent with the differentiation observed from the variation of 16 macromorphological and 9 epidermal traits. Southern and northern regions are clearly differentiated in genetic, morphological and anatomical analyses. These multidisciplinary results suggest that the northernmost populations of D. sonorense represent an ESU that should be included in conservation programs. This study highlights that the evaluation of intraspecific variation may contribute effective strategies for cycad conservation, and that evolutionary processes should be considered in the delimitation of conservation units.

Estrategia estatal de conservación de las cícadas (Zamiaceae): una propuesta para el estado de Hidalgo, México

Mexico has the second largest cycad diversity in the world, and the Sierra Madre Oriental (SMO) is one of the richest biogeographic regions for these plants. Despite there is a general Cycad National Program in the country, there are no state-level cycad conservation strategies or programs. Thus the aim of this study was to propose a cycad conservation strategy for the state of Hidalgo, which is located in the Southern part of the SMO. For this, a cycad species inventory was made in the state, for which three methods were used: review of published literature; consultation in the main Mexican herbaria to verify botanical specimens; and exhaustive field research to compare findings with previously reported species and to recognize new records at the county and state level. The proposed research work strategy combined the following elements: prioritize the county and local areas with greatest cycad species richness; prioritize the species least resistant to environmental change and/or having restricted geographic distribution; and to consider the main uses of these plants by local residents. The results showed that Hidalgo has three genera and eight species ofcycads: Ceratozamia fuscoviridis, C. latifolia, C. mexicana, C. sabatoi, Dioon edule, Zamia fischeri, Z. loddigesii and Z. vazquezii, all of which are considered by the International Union for Conservation of Nature (IUCN). This study added two new species records for Hidalgo and 21 at the county level. The species are distributed in 26 counties, of which Chapulhuacán and Pisaflores are notable for their high species richness. Hidalgo has the fourth-greatest cycad species richness among Mexican states, although its area accounts for only 1.07% of the country. The state's diversity is greater than in other states with larger area, and even than in some other entire countries in Mesoamerica. The presented state cycad conservation strategy proposes that a total of some 11,325 ha to be conserved in nine zones, including different vegetation types, distributed in seven counties. The strategy involves a mixed scheme that incorporates conservation in Protected Natural Areas (ANP), Small Farmer Reserves (Reservas Campesinas) and Environmental Management Units (UMA in Spanish). This proposal will be useful for government agencies to take into account in the process of designating land use for the Cloud Forest Biological Corridor (CBBMM in Spanish), a ANP in creation. The state of Hidalgo urgently needs a detailed analysis of trends in changes in vegetation cover and land use, and demographic studies of the cycads. It is recommended that the implementation phase of this state strategy be carried out jointly with local communities, academia, and state and federal agencies responsible for biodiversity conservation.

Cycad Conservation, Peasant Subsistence, and the Military Coup in Honduras

In rural Honduras, collaborating U.S. and Honduran researchers have elucidated indigenous technical knowledge and customs surrounding local uses for, and conservation of, an endemic cycad—Dioon mejiae Standl. & L. O. Williams (Zamiaceae)—that is an important food source for the lowest economic stratum of local society. Dissemination of research findings within the region has produced positive outcomes for the cycad's conservation without undermining the usufructuary rights of cycad-dependent families. This experience suggests the elements of an effective, low-cost approach to promulgating noncoercive, community-based resource stewardship. However, recent presidential elections notwithstanding, the 2009 coup has undermined the conditions under which participatory research and conservation can take place in Honduras, highlighting the need for researchers and practitioners to consider and confront the assaults on human rights, intellectual freedoms, and natural systems that transpire in the countries where they work.

Elucidating genetic signatures of native and introduced populations of the Cycad Blue, Chilades pandava to Taiwan: a threat both to Sago Palm and to native Cycas populations worldwide

Foreign plants are usually introduced for food or aesthetic reasons. Most of these plants are non-invasive, but can alter the evolutionary trajectory of the associated native insects or inadvertently spread potential pests. A hitherto poorly documented example is the rapid expansion of Chilades pandava, a Cycas-feeding butterfly. Since about 1990, large numbers of the Sago Palm Cycas revoluta were introduced into Taiwan. Invading or introduced with this hostplant, Ch. pandava has rapidly spread to all major parts of Taiwan. To trace the source of outbreaks, we sampled 810 specimens covering 50 Taiwanese localities and other regions using mitochondrial COII sequences. Overall haplotype diversity was high (h = 0.791), but only 29 haplotypes were found. The haplotype C which dominates outbreak populations from western Taiwan was endemic to the island. This is consistent with the hypothesis of a local range expansion of Ch. pandava, rather than an introduction. In addition, the Taiwanese Central Mountain Ridge may constitute a primary biogeographic barrier restricting gene flow between eastern and western populations. Our study not only flags an important new invasive insect that needs to be monitored and controlled within the horticultural trade and for in situ cycad conservation, but also provides a clearly documented case of the transformation of a native tropical butterfly into a pest via introduced horticultural plants.

New Discoveries of Cycads and Advancement of Conservation of Cycads in China

I. Abstract From 1997 to 1999 Cycas debaoensis Y. C. Zhong & C. J. Chen and C. changjiangensis N. Liu were described from South China. The wild populations of Cycas szechuanensis were discovered in Fujian. Cycas guizhouensis K. M. Lan & R. F. Zou at the higher elevations and C. segmentifida D. Y. Wang & C. Y. Deng at the lower elevations along the Nanpanjiang River should be good species, which were treated by Chen and Wang (1995) and Chen and Stevenson (1999) as synonyms for C. szechuanensis. However, 11 other new species have been reduced by Chen and Stevenson (1999) and the present authors. They are C. longlinensis Huang T. Chang & Y. C. Zhong, C. xilinensis Huang T. Chang & Y. C. Zhong, C. multifida Huang T. Chang & Y. C. Zhong, C. longiconifera Huang T. Chang & Y. C. Zhong, and C. acuminatissima Huang T. Chang & Y. C. Zhong, all treated as synonyms of C. segmentifida. Cycas spiniformis J. Y. Liang, C. longisporophylla F. N. Wei, C. septermsperma Huang T. Chang & H. X. Zhang, C. brevipinnata Huang T. ...

A Biotechnology Strategy for Medium- and Long-Term Conservation of Cycads

I. Abstract It has been possible to regenerate a few cycad species in vitro by somatic embryogenesis, either from zygotic embryos (Ceratozamia hildae, C. mexicana, Encephalartos cycadifolius, E. dyerianus, E. natalensis, Zamia fischeri, Z. furfuracea, and Z. pumila) or from leaves of mature phase trees (C. euryphyllidia, Ceratozamia hildae, and C. mexicana). This strategy has great potential for the commercial vegetative propagation of certain highly endangered species (e.g., C. euryphyllidia) and should indirectly protect wild populations of these species by discouraging collection in situ. Embryogenic cultures of several cycad species have grown vigorously and are highly morphogenic more than 11 years after induction. The long-term conservation of cycad genetic resources can also be addressed for species that can be regenerated by somatic embryogenesis. Preliminary studies indicate that embryogenic cultures that have been pretreated on plant growth medium containing 0.75 M sucrose for two days, encapsul...

The world cycad census and a proposed revision of the threatened species status for cycad taxa

The numbers of mature specimens of all extant cycad taxa in the wild, in public gardens and in private collections were estimated from a census carried out during 1991 and 1992. The data for the wild plants and those in public gardens appear to be comprehensive and reasonably accurate for most cycad genera except Cycas and Zamia. A low frequency of responses from private collectors has resulted in a significant underestimate of the number of specimens in private ownership. Abundance in the wild is extremely variable but, with some important exceptions, positively correlated with numbers in cultivation, where large numbers of plants are held by a relatively small number of owners. Revisions of the previously listed conservation status for each taxon are suggested on the basis of wild number estimates in view of the lack of detailed population studies. Well-maintained and correctly accessioned cycad collections are important ex situ genetic resources of educational, research and conservation value; several botanic gardens are presently involved in cycad conservation projects. A major revision of the earlier threatened species assignments is proposed, in which taxa are placed into extinct, critical, endangered, vulnerable and safe/low-risk categories on the basis of the wild number estimates obtained in the census. These assignments are based on species numbers in view of the lack of data at the population level.

Gap analysis for in situ conservation of crop genepools: implications of the Convention on Biological Diversity: G. B. Ingram & J. T. Williams, Biodiversity Letters, 1(5), 1993, pp 141–148

The numbers of mature specimens of all extant cycad taxa in the wild, in public gardens and in private collections were estimated from a census carried out during 1991 and 1992. The data for the wild plants and those in public gardens appear to be comprehensive and reasonably accurate for most cycad genera except Cycas and Zamia. A low frequency of responses from private collectors has resulted in a significant underestimate of the number of specimens in private ownership. Abundance in the wild is extremely variable but, with some important exceptions, positively correlated with numbers in cultivation, where large numbers of plants are held by a relatively small number of owners. Revisions of the previously listed conservation status for each taxon are suggested on the basis of wild number estimates in view of the lack of detailed population studies. Well-maintained and correctly accessioned cycad collections are important ex situ genetic resources of educational, research and conservation value; several botanic gardens are presently involved in cycad conservation projects. A major revision of the earlier threatened species assignments is proposed, in which taxa are placed into extinct, critical, endangered, vulnerable and safe/low-risk categories on the basis of the wild number estimates obtained in the census. These assignments are based on species numbers in view of the lack of data at the population level.

Guidelines for the development of community level habitat evaluation models : R. L. Schroeder & S. L. Haire, Biological Report - US Fish & Wildlife Service, 8, 1993, 8 pp

The numbers of mature specimens of all extant cycad taxa in the wild, in public gardens and in private collections were estimated from a census carried out during 1991 and 1992. The data for the wild plants and those in public gardens appear to be comprehensive and reasonably accurate for most cycad genera except Cycas and Zamia. A low frequency of responses from private collectors has resulted in a significant underestimate of the number of specimens in private ownership. Abundance in the wild is extremely variable but, with some important exceptions, positively correlated with numbers in cultivation, where large numbers of plants are held by a relatively small number of owners. Revisions of the previously listed conservation status for each taxon are suggested on the basis of wild number estimates in view of the lack of detailed population studies. Well-maintained and correctly accessioned cycad collections are important ex situ genetic resources of educational, research and conservation value; several botanic gardens are presently involved in cycad conservation projects. A major revision of the earlier threatened species assignments is proposed, in which taxa are placed into extinct, critical, endangered, vulnerable and safe/low-risk categories on the basis of the wild number estimates obtained in the census. These assignments are based on species numbers in view of the lack of data at the population level.