Traditional knowledge and genetic diversity ofopuntia pilifera (cactaceae) in the tehuacán-cuicatlán valley, Mexico

Traditional Knowledge and Genetic Diversity of Opuntia pilifera (Cactaceae) in the Tehuacán-Cuicatlán Valley, Mexico. Economic Botany 59(4)366-376, 2005. Most studies of the genusOpuntia have focused on economically important species, and therefore more knowledge concerning the genetic diversity among wild and locally managedOpuntia species is needed for an expanded use of cacti in the future. The present study is part of ongoing ethnobotanical work in the Tehuacán-Cuicatlán Valley of Mexico and focuses on six traditionally classified forms ofOpuntia pilifera used as food by the indigenous Popoloca people in San Juan Atzingo. Traditional knowledge of how to distinguish these forms based on fruit flavor, color, size, and number of spines on the fruits and cladodes is preserved in the local community. Genetic fingerprinting with 129 AFLPs did not correlate with this traditional morphological classification of 67 cacti. Yet, these AFLPs distinguished the analyzed 67Opuntia pilifera cacti easily from the out-group comprising 17 wildOpuntia velutina.     

<Emphasis Type="Italic">In situ</Emphasis> Management and Patterns of Morphological Variation of <Emphasis Type="Italic">Ceiba aesculifolia</Emphasis> subsp. <Emphasis Type="Italic">parvifolia</Emphasis> (Bombacaceae) in the Tehuacán-Cuicatlán Valley

In situ Management and Patterns of Morphological Variation of Ceiba aesculifolia subsp. parvifolia (Bombacaceae) in the Tehuacán-Cuicatlán Valley. Archaeological studies in Mexico’s Tehuacán Valley that were conducted during the 1960s revealed that the prehistoric use of “pochote” Ceiba aesculifolia was mainly for its edible roots and seeds. Recent ethnobotanical studies in the villages of Coxcatlán, San Rafael, and San José Tilapa, municipality of Coxcatlán, Puebla, documented that currently seeds are the most important plant parts of this tree used in the region. Local people recognize three morphological types of pochote trees: the purple-reddish, the pale green, and the dark-green reddish fruit variants, the first two being preferred because of their larger and more abundant seeds. This study documents the patterns of morphological variation of C. aesculifolia in human-managed and unmanaged populations in the communities just mentioned in order to analyze whether management has been directed to favor abundance of morphological types preferred by people. The main morphological types named by people were characterized by morphometric studies, and their frequencies in populations under different management intensity were evaluated through vegetation sampling. The morphometric studies corroborated that the morphological types recognized by people are identifiable groups, whereas vegetation sampling revealed that pochote variants preferred by people (the purple-reddish fruit type) were relatively more abundant in human-managed areas than in natural vegetation. This information suggests the occurrence of artificial selection associated with in situ management of this plant species.     

Demography of the columnar cactus Neobuxbaumia macrocephala: a comparative approach using population projection matrices

Neobuxbaumia macrocephala is a long-lived columnar cactus endemic to the Tehuacán-Cuicatlán Valley in south-central Mexico. This plant has a very restricted distribution and few recruitment events have been detected in its populations. In this study, we analyze the N. macrocephala demographic pattern using a projection matrix in order to determine the main limiting factors of this species. To accomplish this goal, we compare our results with those obtained for another species of the same genus, N. tetetzo. Considering that both species inhabit the same valley, we believe that this comparative study will offer insights into the main demographic limitations of N. macrocephala. Results showed that these species of columnar cacti have similar demographic patterns in which survival is the process with the highest relative contribution to λ, followed by growth and reproduction. Of all the life cycle stages, seeds and seedlings have the lowest survival probabilities due to a high mortality caused by seed predation and effects of direct solar radiation on germinated seeds. The estimated growth rates indicate that populations of these species of Neobuxbaumia are in a numerical equilibrium. With respect to reproduction, N. macrocephala produce a lower number of seeds per plant than N. tetetzo. This low level of sexual reproduction may decrease the probability of establishment of new individuals in N. macrocephala populations. It is suggested that pollen limitation and pre-dispersal seed predation could be some factors that limit the distribution and abundance of this columnar cactus. This revised version was published online in June 2006 with corrections to the Cover Date.     

Cytotoxic diterpenes from roots of Crossopetalum gaumeri,a Celastraceae species from Yucatan Peninsula

Four new diterpenes, crossogumerins A–D (1–4) along with six known ones (5–10) were isolated from the root bark of Crossopetalum gaumeri, an endemic medicinal plant from the Yucatan Peninsula. Their structures were elucidated on the basis of 1D and 2D NMR techniques, including HMQC, HMBC, and ROESY experiments. Compounds 1–5, 8–10 were evaluated for cytotoxicity against HeLa (carcinoma of the cervix) and Hep-2 (lung carcinoma) human tumor cells lines and against normal Vero cells (African green monkey kidney) in lag and log phase of growth. Podocarpane diterpenes, crossogumerin B (2) and nimbiol (10), exhibited the highest activity against HeLa cells (IC₅₀ values of 3.1 and 8.1 μM, respectively), but also selectivity on Vero cells (SI 22.6 and 7.5, respectively). The preliminary SAR studies suggest that an epoxy moiety in ring B and a hydrogen bond-donor group strategically positioned in the diterpene core are important requirements for cytotoxicity and selectivity.     

Studies in Neotropical paleobotany. XIV. A palynoflora from the Middle Eocene Saramaguacan Formation of Cuba

An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacán Formation, Camagüey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleoclimate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacán flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America.     

Fire and resprouting in Mediterranean ecosystems: insights from an external biogeographical region, the mexical shrubland

We investigated modes of regeneration of dominant species of the mexical vegetation after fire. The mexical shrubland shows a remarkable structural, morphological, and floristic similarity to Mediterranean-type vegetation and is considered a relict of the Madro-Tertiary Geoflora under a non-Mediterranean climate. This vegetation provides an ideal scenario to test the role of fire in Mediterranean ecosystems because historical fire occurrence is absent and the species assembly is constituted mostly by Madro-Tertiary elements and Neotropical species (some of them, endemic species from Mexico). The existence of congeneric species of the California chaparral allows us to determine the regeneration ability of these communities after fire in relation to resprouting and seeding strategies, which are widespread modes reported in the Mediterranean-type vegetation. By the experimental application of fire in the two biogeographical groups of species, we tested the hypothesis that low resprouting ability of California congeneric species (Madro-Tertiary species) after fire would indicate that fire has played an important selective force in the resprouting habit. A low resprouting ability in the Neotropical group of species would suggest that fire has molded the set of species dominating fire-prone environments.Our results indicated that resprouting is a widespread trait in the mexical species characterized by the presence of lignotubers and burls. Resprouting can be considered an ancient trait, probably linked to losses of aboveground biomass, that became a pre-adaptation in Mediterranean fire-prone communities. The Neotropical group of species showed less ability to regenerate after fire, and small plants were more likely to die after disturbance in this group than in the Madro-Tertiary group. The resprouting feature and the seeder strategy of other species after a fire in the mexical shrubland are similar to Mediterranean-type ecosystems, emphasizing their common origin and the relevance of phylogenetic and biogeographical studies to explain current patterns of vegetation.     

Effect of Zuccagnia punctata Cav. (Fabaceae) extract on pro-inflammatory enzymes and on planktonic cells and biofilm from Staphylococcus aureus. Toxicity studies

Zuccagnia punctata Cav. (Fabaceae), a native plant from Argentina has been used traditionally as medicinal species. The aim of the study was to validate the antibiotic and anti-inflammatory potential of Z. punctata organic extract (ZpE) and the major compounds; 2′,4′-dihydroxy-3′-methoxychalcone (DHMC), 2′,4′-dihydroxychalcone (DHC), 7-hydroxyflavanone (7-HF) and 3,7-dihydroxyflavone (DHF); using an in vitro model. The antibiotic activity was determined using a broth microdilution method and the minimum inhibitory concentration (MIC) was determined. The extract and the isolation compounds affect the normal growth of all assayed Staphylococcus aureus strains. The MIC values for ZpE and isolated compounds were between 125 and 500 μg/mL and between 25 and 400 μg/mL, respectively, against all assayed strains. The inhibitory effect of extract and isolated compounds on biofilm formation and on pro-inflammatory enzymes (sPLA₂, COX-2, LOX) was analyzed. The compound DHC was the most active on sPLA₂ while DHF and DHMC showed the highest activity on LOX. Both the extract and pure compounds except DHMC were active against COX-2. It can be concluded that the phytocomplex and the pure compounds possessed antibiotic and anti-inflammatory activities under the conditions tested, and could be a good alternative therapy for infective and inflammatory processes.     

喀斯特槽谷区生态退化与修复专题导读

在国家重点研发计划项目——"喀斯特槽谷区土地石漠化过程及综合治理技术研发与示范(2016YFC0502300)"的支持下,经过项目组全体成员三年的共同努力,在喀斯特槽谷区生态退化与修复方面取得了一些重要进展。主要有:(1)2000—2015年槽谷区土壤侵蚀总量逐年减少,年平均侵蚀模数逐年降低,槽谷区植被覆盖明显提高;(2)拉巴豆地埂篱根土复合体不仅能有效提高喀斯特土壤的粒径大小和增强土体的抗剪/冲性能,并且能够利用大气N_2合成植物生长所需的氮肥,从而提高土壤肥力,可望实现石漠化治理中生态效应和经济效应的双赢;(3)喀斯特槽谷区隧道建设改变了地下水流场并降低了地下水位,进而降低了土壤微生物丰度和多样性,而增加了适应干旱的微生物种群,并导致土壤质量的降低;隧道建设加速了坡面产流和土壤流失,加剧了土地石漠化,从而导致生态退化;(4)随着槽谷区退化生态系统的恢复,生态系统的生态服务功能得到提升。     

Determinants of Land Degradation and Fragmentation in Semiarid Vegetation at Landscape Scale

The objective of this paper was to investigate the sensitivity to degradation of semiarid plant communities in terms of plant cover and fragmentation, quantifying relationships between landscape characteristic (physical, socio-economical and historical) and vegetation degradation. The degradation of vegetation was measured as the degree of coverage of the two dominant vegetation types (i.e. tall arid brush and tall grass steppe), while fragmentation was measured as patch size and isolation. Data were obtained using GIS tools, and analyzed by logistic regression and linear multivariate regression. Results showed denser coverage at more elevated, gradual slopes that were not sea-oriented. Historical elements of the landscape had a significant effect on current natural vegetation. According to the fragmentation patterns, the vegetation is in fairly good condition (medium coverage had the largest patches but dense coverage was less isolated) but attention must be given to preserve vegetation, due to the relationships between fragmentation and human activities. Moreover, the protection plan under way in the area appeared to favour denser vegetation cover, while human activities had a measurable effect on vegetation degradation.     

Changes in lepidopteran assemblages in Temnosmrečinská dolina valley (the High Tatra Mts,Slovakia) over the last 55 years

Lepidopteran assemblages in Temnosmrečinská dolina valley (High Tatra Mts, Western Carpathians, Slovakia) were investigated. Recent data about the occurrence of lepidopteran species are compared with those which were obtained 55 years ago. Lepidoptera were monitored at seven sites comprising the subalpine to alpine zone of the valley. Fifteen of the originally recorded species were not found, however, the occurrence of six new species was recorded. In total, 61 summer lepidopteran species are known from the Temnosmrečinská dolina valley. The comparison of the recent lepidopteran assemblages shows a decline in species richness, abundance and frequency at individual monitoring sites. It seems that the changes are caused by plant community succession in the valley — overgrowth of dwarf pine, transformation of meadow communities to Calamagrostigetum and overgrowth of peat-bogs, resulting in loss of food resources for adult Lepidoptera.     

Passiflora tacanensis, a new species of Passiflora subgenus Decaloba supersection Cieca from Mexico

Passiflora tacanensis, a new species from southern Mexico, is described and illustrated. It was discovered during the course of a taxonomic revision ofPassiflora subgenusDecaloba supersectionCieca and is assigned to that group of apetalous passion flowers.Passiflora tacanensis is known only from one fruiting herbarium specimen that was collected in southern Mexico on Volcán Tacaná in a high mesophytic forest. It is distinguished from its closest relatives,P. coriacea, P. sexocellata, P. mcvaughiana, andP. xiikzodz, by its foliose stipules, leaves that lack laminar nectaries but possess petiolar nectaries, and wide seeds with a chalazal beak that is not well developed.     

The effect of land management on plant community composition, species diversity, and productivity of alpine Kobersia steppe meadow

Grassland degradation is widespread and severe on the Tibet Plateau. To explore management approaches for sustainable development of degraded and restored ecosystems, we studied the effect of land degradation on species composition, species diversity, and vegetation productivity, and examined the relative influence of various rehabilitation practices (two seeding treatments and a non-seeded natural recovery treatment) on community structure and vegetation productivity in early secondary succession. The results showed: (1) All sedge and grass species of the natural steppe meadow had disappeared from the severely degraded land. The above-ground and root biomass of severely degraded land were only 38 and 14.7%, respectively, of those of the control. So, the original ecosystem has been dramatically altered by land degradation on alpine steppe meadow. (2) Seeding measures may promote above-ground biomass, particularly grass biomass, and ground cover. Except for the grasses seeded, however, other grass and sedge species did not occur after seeding treatments in the sixth year of seeding. Establishment of grasses during natural recovery treatment progressed slowly compared with during seeding treatments. Many annual forbs invaded and established during the 6 years of natural recovery. In addition, there was greater diversity after natural recovery treatment than after seeding treatments. (3) The above-ground biomass after seeding treatment and natural recovery treatment were 114 and 55%, respectively, of that of the control. No significant differences in root biomass occurred among the natural recovery and seeded treatments. Root biomass after rehabilitation treatment was 23–31% that of the control.     

黄河流域水鸟保护优先区及空缺

黄河流域为迁徙水鸟提供重要的繁殖地、越冬地和停歇地。然而,黄河流域正面临着农业开垦、城市化、水资源分布不均等一系列的生态安全问题,威胁迁徙水鸟种群及其栖息地稳定性。因此,识别黄河流域重要的水鸟栖息地分布区域,分析当前的保护现状对于开展水鸟及栖息地保护至关重要。以黄河流域为研究区,搜集整合来自国内外观鸟网站(eBird、全球生物多样性信息库(GBIF)和中国观鸟记录中心(BirdReport))、文献和水鸟调查报告中的水鸟调查数据,沿用三个国际上通用的水鸟重要栖息地识别标准,确定了黄河流域水鸟保护优先区。在此基础上,使用水鸟栖息地重要性指数确定水鸟保护优先区保护优先等级,结合国家自然保护地名录,分析水鸟保护优先区保护空缺状况。结果显示:黄河流域共有47个水鸟保护优先区,主要分布在黄河流域中游和下游,其中河南省和山东省水鸟保护优先区较多。满足水鸟保护优先区识别标准的水鸟共14种,其中,极危物种有2个,濒危物种有1个,易危物种有5个。水鸟保护优先区保护优先等级处于I、II和III类的分别有2个、8个和37个。有20个水鸟保护优先区处于保护空缺状态,占总数的42.55%,主要集中在黄河中游和下游,其中,水鸟保护优先等级处于I类或II类的地块有3个,建议将这些保护空缺地以自然保护区、保护小区或国家公园形式纳入湿地保护地体系,并加强长期监测。