Orchids reduce attachment of herbivorous snails with leaf trichomes

Protective structures in the epidermis are essential for land plants to defend themselves against herbivores. In this study, we investigated the effect of different types of trichomes of three orchids, Calanthe triplicata, Dendrochilum pallidiflavens and Trichotosia ferox, on attachment of herbivorous land snails, using histochemistry and centrifuge experiments. Size, ornamentation and histochemistry of epicuticular trichomes on the orchid leaves were assessed with light microscopy, scanning electron microscopy and transmission electron microscopy. Total forces needed to detach two differently shaped snail species, Subulina octona and Pleurodonte isabella, were measured using a turntable equipped with a synchronized strobe. Snails were placed in two positions, either perpendicular or parallel to the main veins on the orchid leaves, both on the adaxial (= upper) or abaxial (= lower) side. The results obtained provided three new insights. First, a perpendicular or parallel position of the snails to the main veins did not significantly affect the attachment performance of either species tested. Secondly, snails detached significantly easier on leaf sides covered with a high density of lignin filled epicuticular trichomes. Thirdly, the removal of glandular trichomes did not affect the attachment forces; however, the absence of lignified trichomes increased the attachment of the snails. Our study highlights the importance of studying micro-ornamentation in combination with performance for obtaining a better understanding of the defense mechanisms employed by different species of orchids to deter herbivorous snails.

Restoration success in former Amazonian mines is driven by soil amendment and forest proximity

Mining contributes importantly to tropical deforestation and land degradation. To mitigate these effects, mining companies are increasingly obliged to restore abandoned mine lands, but factors driving restoration success are hardly evaluated. Here, we investigate the influence of ecological factors (restoration age, soil properties and surrounding forest area) and management factors (diversity and density of planted species, mine zone) on the recovery rate of forest structure and tree diversity on 40 post-mining restoration areas in Southern Amazonia, Brazil, using a 9-year annual monitoring dataset consisting of over 25 000 trees. We found that recovery of forest structure was closely associated with interactions between soil quality and the planted tree communities, and that tree diversity recovery was positively associated with the amount of surrounding forests. We also observed that forest structure and diversity recover more slowly in mine tailings compared to pit surroundings. Our study confirms the complexity of mine land restoration but also reveals that planting design and soil improvement can increase restoration success. For resource-efficient mine restoration, we recommend the focusing of efforts on tailings, which are hardest to restore, and reducing efforts in pit surroundings and areas close to surrounding forest because of their potential for restoration by natural regeneration. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

The importance of choosing appropriate methods for assessing wild food plant knowledge and use: A case study among the Baka in Cameroon

In tropical rainforests, access to and availability of natural resources are vital for the dietary diversity and food security of forest-dwelling societies. In the Congo Basin, these are challenged by the increasing exploitation of forests for bushmeat, commercial hardwood, mining, and large-scale agriculture. In this context, a balanced approach is needed between the pressures from forest exploitation, non-timber forest product trade and the livelihood and dietary behavior of rural communities. While there is a general positive association between tree cover and dietary diversity, the complex biocultural interactions between tropical forest food resources and the communities they sustain are still understudied. This research focuses on the knowledge and use of wild food plants by the forest-dwelling Baka people in southeast Cameroon. By using two different sets of methods, namely ex-situ interviews and in-situ surveys, we collected ethnographic and ethnobotanical data in two Baka settlements and explored the diversity of wild edible plants known, the frequency of their consumption, and potential conflicts between local diet and commercial trade in forest resources. Within a single Baka population, we showed that the in-situ walk-in-the-woods method resulted in more detailed information on wild food plant knowledge and use frequency than the ex-situ methods of freelisting and dietary recalls. Our in-situ method yielded 91 wild edible species, much more than the ex-situ freelisting interviews (38 spp.) and dietary recalls (12 spp.). Our results suggest that studies that are based only on ex-situ interviews may underestimate the importance of wild food plants for local communities. We discuss the limitations and strengths of these different methods for investigating the diversity of wild food plant knowledge and uses. Our analysis shows that future studies on wild food plants would profit from a mixed approach that combines in-situ and ex-situ methods.

Sustainability issues of commercial non-timber forest product extraction in West Suriname

BACKGROUND

Non-timber forest products (NTFPs) have been traded for millennia by indigenous communities. Current increased demands driven by globalisation, however, put more pressure on local harvesters and their surrounding ecosystems. The safeguarding of indigenous access rights to harvesting grounds is needed, either through communal land titles or collaborative management agreements, both to secure prior indigenous rights and to minimise further negative ecological impacts.

METHODS

This study was carried out in two indigenous communities in West Suriname located along the Corentyne River. We assessed the three economically most important NTFPs for each community. We determined the land tenure status of harvesting grounds and negative impacts on target species and/or ecosystem. Ethnobotanical data were collected (n = 53), and semi-structured interviews were held with hunters and gatherers (n = 13). Local and national maps were acquired, and their data merged.

RESULTS

Results showed that the communities have no tenure security over their most important harvesting sites. These collection sites are State owned and some under (active) logging concession. All of the traded wild animal populations had decreased because of increased local and non-local commercial interest, especially the stingray Potamotrygon boesemani (first described in 2008), which was traded for US$250 per live specimen. The stingray population had become imperilled within months as local and (inter-) national regulations for this species are non-existent.

CONCLUSIONS

We stress the urgent need for collaborative management agreements over the harvesting sites between the government of Suriname and the indigenous communities to prevent further non-local developments and harvesting to disturb the local economy. An immediate moratorium on the export of P. boesemani is necessary to prevent the extinction of this endemic stingray.

Ethnobotany of the Sierra Nevada del Cocuy-Güicán: climate change and conservation strategies in the Colombian Andes

BACKGROUND

The Sierra Nevada del Cocuy-Güicán in the Colombian Andes is protected as a National Natural Park since 1977 because of its fragile páramo ecosystems, extraordinary biodiversity, high plant endemism, and function as water reservoir. The vegetation on this mountain is threatened by expanding agriculture, deforestation, tourism, and climate change. We present an ethnobotanical inventory among local farmer communities and discuss the effects of vegetation change on the availability of useful plants.

METHODS

We used 76 semi-structured, 4 in-depth interviews, and 247 botanical collections to record the ethnoflora of the farmers and surveyed from the high Andean forest to the super-páramo, including native and introduced species. We organized 3 participative workshops with local children, high school students, and campesinos' women to share the data we acquired in the field and empower local plant conservation awareness.

RESULTS

We encountered 174 useful plants, most of them native to the area (68%) and almost one third introduced (32%). The Compositae was the most species-rich family, followed by Lamiaceae, Poaceae, and Rosaceae. The majority of plant species were used as medicine, followed by food, firewood, and domestic tools. Local farmers reported declining numbers of páramo species, which were now only found at higher altitudes than before. Although our informants were worried about the preservation of their natural resources and noticed the effects of climate change, for several commercial species, unsustainable land use and overharvesting seemed to be the direct cause of declining medicinal plant resources rather than climate change.

CONCLUSIONS

We recommend conservation plans that include vegetation monitoring, people's perceptions on climate change, and participative actions with the communities of the Sierra Nevada del Cocuy-Güicán.

Indigenous Children's Knowledge About Non-timber Forest Products in Suriname

Childhood and adolescence are important life stages for the acquisition of knowledge about non-timber forest products (NTFPs). We show at which stage in life traditional plant knowledge is learned and analyze whether cross-cultural ethnobotanical knowledge transmission takes place. We evaluate whether the degree of forest dependency influences ethnobotanical knowledge by comparing two indigenous communities in Suriname. Traditional knowledge was documented and vouchers collected during forest walks with adult informants. Questionnaires were completed by 74 schoolchildren (age 4 to 14) to capture their knowledge of names and uses of nine important NTFPs. We tested for knowledge differences by ethnicity and NTFP categories. Local names for NTFPs were analyzed to determine cross-cultural transmission of ethnobotanical knowledge. Children from the forest-dependent Trio community (n = 23) possessed similar knowledge of NTFPs as their more urbanized peers from Apoera (n = 51). NTFP uses were acquired at an earlier age than plant names. Food and commercial NTFP uses were better known than medicinal plant uses. Cross-cultural transfer of knowledge occurred between the two communities. NTFP knowledge of children appeared to be influenced more by the time they spent within the forest, either walking to school or walking to agricultural plots, than by the level of forest dependency or acculturation.

The Trade in African Medicinal Plants in Matonge-Ixelles, Brussels (Belgium)

Maintaining cultural identity and preference to treat cultural bound ailments with herbal medicine are motivations for migrants to continue using medicinal plants from their home country after moving to Europe and the USA. As it is generally easier to import exotic food than herbal medicine, migrants often shift to using species that double as food and medicine. This paper focuses on the trade in African medicinal plants in a Congolese neighborhood in Brussels (Belgium). What African medicinal plants are sold in Matonge, where do they come from, and to which extent are they food medicines? Does vendor ethnicity influence the diversity of the herbal medicine sold? We hypothesized that most medicinal plants, traders, and clients in Matonge were of Congolese origin, most plants used medicinally were mainly food crops and that culture-bound illnesses played a prominent role in medicinal plant use. We carried out a market survey in 2014 that involved an inventory of medicinal plants in 19 shops and interviews with 10 clients of African descent, voucher collection and data gathering on vernacular names and uses. We encountered 83 medicinal plant species, of which 71% was primarily used for food. The shredded leaves of Gnetum africanum Welw., Manihot esculenta Crantz, and Ipomoea batatas (L.) Lam were among the most frequently sold vegetables with medicinal uses. Cola nuts, shea butter, Aloe vera (L.) Burm.f., and Mondia whitei (Hook.f.). Skeels were the main non-food medicines sold. Women's health, aphrodisiacs, and rituals were the most important medicinal applications, but culture-bound ailments did not entirely dominate the plant uses. While most clients in Matonge were Congolese, most vendors and plant species were not. The Pakistanis dominated the food trade, and typical Congolese plants were sometimes replaced by West African species, creating confusion in vernacular names. African-managed shops had significantly more species of medicinal plants in stock than shops managed by Pakistanis. Almost all non-food herbal medicine was sold by Africans. Apart from informal shops, non-food herbal medicine was also sold from private homes and by ambulant vendors, probably to reduce costs and escape taxes and control by the authorities. We expect that in the future, increasing rent, strict regulations, and decreasing investments by the Congolese community will force the medicinal plant trade in Matonge to go even more underground.