Plant community ecology of Pinus sylvestris, an extirpated species reintroduced to Ireland

Plantation forests can make a significant contribution to the conservation of native biodiversity, especially where native forest cover is low. Ireland is used as a case study to explore the contribution to biodiversity made by stands of Pinus sylvestris (Scots pine), a reintroduced species. Despite its disputed native status, P. sylvestris is being widely planted in semi-natural habitats in Ireland. The associated vegetation communities have not previously been described and their conservation value is unknown. Baseline information is needed to inform conservation and forest management strategies. Botanical surveys were carried out at 20 plots of P. sylvestris-dominated woodland and scrub throughout the Republic of Ireland. Vegetation, structural and environmental data were recorded. Data were analysed using non-parametric and multivariate statistical techniques and a synoptic table was prepared. P. sylvestris was found to be a non-specialist in terms of its environmental tolerances. β diversity among plots was high while α diversity within plots was low to moderate. The plots surveyed contained 14.2% of the Irish native flora. There was a low level of constancy of species. Four reasonably well defined vegetation communities were identified. Soil pH, altitude and slope had important roles in partitioning these vegetation types and soil pH was positively correlated with species richness. P. sylvestris is well established, well integrated and naturalising in Irish semi-natural habitats. Some of the associated vegetation communities corresponded to habitats of international conservation importance. This research demonstrates that stands of P. sylvestris represent an important resource for Ireland’s native botanical and habitat diversity.     

Terrestrial isopod diversity in the wadi Moula‐Bouterfess catchment area (Kroumirie,north‐west of Tunisia)

We assessed the diversity of terrestrial isopods according to habitat and altitude in the wadi of Moula‐Bouterfess catchment area. The most representative habitat types for the area were selected within altitudinal range from 6 to 550 m a.s.l. In total nine sites were sampled: four with maquis and garrigue vegetation, one at a meadow and four sites with forest vegetation. In each sampled habitat, individuals were collected by hand in April 2005 using 30 replicates of a quadrate of 0.5 × 0.5 m. During the study, 582 individuals belonging to 11 terrestrial isopod species from five families were collected. Among these, three species were newly mentioned in Tunisia. The genus Armadillidium was the most abundant genus (60% of the total number of collected specimens) and P. variabilis was the most common species as it was sampled in eight of the nine studied habitats. Terrestrial isopod community structure differs among the nine sampling habitats. Abundance and species richness values are low in the different studied habitats. The Shannon–Wiener H′ varied from 0.67 to 2.06. The Canonical Correspondence Analysis (CCA) applied to our data showed that the majority of terrestrial isopod species seem to be more sensitive to vegetal associations than to altitude. No relationship was found between species richness/diversity (Shannon–Wiener index H’) and altitude. The studied sites were separated into open and closed areas based on the Bray–Curtis index for similarity.     

Recovery after Experimental Cutting and Burning in Three Shrub Communities with Different Dominant Species

The aim of this study is to compare the recovery dynamics in three shrub communities subjected to experimental burning and cutting, and situated on an altitudinal gradient. Climatic features are different in each area, but all had the common characteristic of very homogeneous vegetation cover before the disturbances, with only one shrub species clearly dominant, a different taxon in each area, and with different regeneration strategies. The first area was a heathland dominated by Calluna vulgaris, situated at an altitude of 1600 m, with a continental climate (mean annual precipitation 1320 mm). The second area was a heathland dominated by Erica australis, located at an altitude of 1000 m (mean annual precipitation 840 mm). The third area was a Cistus ladanifer shrubland, located at 900 m altitude, with a Mediterranean climate similar to that of the previous area, but with lower mean annual precipitation (470 mm). Erica australis recovers by vegetative resprouting, but Cistus ladanifer is an obligate seeder, as is Calluna vulgaris in these areas. Each experimental disturbance was carried out over 100 m² in each area. Post-fire recovery is faster in Cistus ladanifer: 2 years after burning there was 40% cover vs. less than 20% in the other two species. However, recovery after cutting was similar for Cistus ladanifer and Erica australis. Calluna vulgaris recovers very slowly, with cover values below 20% even 10 years after both disturbances. Cover of dominant shrub species is negatively correlated with cover of herbaceous species. So different recovery of dominant species lead a different community dynamic in each area.     

江西赣江源区域两栖动物的群落组成和物种多样性特征

赣江发源于武夷山脉南段西麓的高山岭间,该区域独特的地理环境和气候特征蕴育了丰富的生物多样性。然而关于该区域两栖动物群落组成和物种多样性调查非常匮乏,不利于赣江源头两栖动物物种多样性的保护。于2016年4-9月期间在江西赣江源区域采用样线法调查了两栖动物的资源状况、群落组成及物种多样性特征,比较了它们在山地森林区、丘陵森林与农田区和盆地农田区3类栖息地之间的差异性。结果表明：赣江源区域分布有8科23种两栖动物,新增记录3个物种,包括尖舌浮蛙、寒露林蛙和九龙棘蛙,泽陆蛙和饰纹姬蛙为优势种。赣江源区域的两栖动物群落组成和物种多样性存在显著的季节间差异和栖息地间差异;两栖动物季节性繁殖是造成前者差异的主要因素,而土地利用类型、栖息地特征、空间距离、生活习性的物种特性等因素成就了后者差异的出现。因此,春、夏季一般有比秋季见到更高的两栖动物物种丰富度和多样性;山地森林区的两栖动物物种丰富度和多样性最高,盆地农田区次之,丘陵森林与农田区的最低。山地森林区应成为赣江源区域两栖动物多样性保护的优先区域。国家Ⅱ级重点保护野生动物虎纹蛙,在3类栖息地中均有分布,且在盆地农田区和山地森林区能见到更多个体,但农田区分布的虎纹蛙遭受到更大的威胁,建议加强对农田区虎纹蛙及其栖息地的保护。     

Patch occupancy in the endangered butterfly Lycaena helle in a fragmented landscape: effects of habitat quality, patch size and isolation

While there is agreement that both habitat quality and habitat network characteristics (such as patch size and isolation) contribute to the occupancy of patches by any given species, the relative importance of these factors is under debate. This issue is of fundamental ecological importance, and moreover of special concern for conservation biologists aiming at preserving endangered species. Against this background we investigated patch occupancy in the violet copper Lycaena helle, one of the rarest butterfly species in Central Europe, in the Westerwald area (Rhineland-Palatinate, Western Germany). Occupied (n = 102) differed from vacant (n = 128) patches in altitude, size, connectivity, availability of wind shelter, in the abundance of the larval host-plant, in the abundance of a grass species indicating favorable habitat conditions and in the abundance of nitrophilous plants. Overall, patch occupancy was primarily determined by patch size, connectivity and the abundance of the larval host plant, while all other parameters of habitat quality were of subordinate importance. Therefore, our findings suggest that even for extremely sedentary species such as L. helle habitat networks are decisive and—next to the preservation of habitat quality—need to be an integral part of any conservation management for this species.     

乌鲁木齐达坂城山区地衣生态位特征的研究

为揭示达坂城山区地衣对生境资源的利用状况及竞争程度,该研究在野外设置30个样方并调查其物种盖度数据,利用生态位宽度、生态位重叠指数及排序分析,探讨达坂城山区地衣的生态位特征及环境影响因子。结果表明:(1)达坂城山区生态位最宽的为丽黄鳞衣(Rusavskia elegans)和内卷野粮衣(Circinaria contorta),对不同环境具有较强的适应性,其他地衣物种生态位宽度较窄,对环境资源利用程度低。(2)物种间生态位重叠值整体偏低,生态位重叠值较高的物种对极少,地衣物种生态位分化程度高,物种间竞争不激烈。(3)生态位较宽的物种与多数物种之间都存在生态位重叠,但重叠值较低; 一些生态位较窄的物种与其他物种之间的生态位重叠值较高; 生态位重叠和生态位宽度之间并无直接的线性关系。(4)地衣物种沿海拔梯度分布具有差异,海拔、光照强度、湿度、风速和人为干扰是本地区地衣群落物种生态位特征差异的主导环境因子。综上所述,达坂城山区地衣物种由于生境资源的竞争占据各自独特的生态位,形成了生态位的分化,群落较为稳定,沿海拔梯度的生境条件差异是物种差异分布的重要原因。该研究可为地衣群落构建研究提供理论依据,并对该地区地衣物种的多样性和生境保护具有重要意义。     

老爷岭南部狍冬季移动、卧息生境选择及其适宜性评价

在动物生境研究中,移动生境和卧息生境是生境研究的焦点。开展移动生境和卧息生境选择,并在此基础上进行生境评价,有利于深入了解动物对移动和卧息生境条件的需求,制定科学合理的栖息地保护计划。以东北虎（Panthera tigris altaica）的主要猎物物种之一-狍（Capreolus pygargus）为研究对象,于2017-2019年冬季积雪覆盖期在老爷岭南部通过随机布设28个大样方和84条用于足迹链跟踪的样线收集狍的移动点和卧息点信息,再结合近年来收集的东北虎出现点,利用广义可加模型（GAM）和最大熵模型（MaxEnt）进行狍移动、卧息生境选择及评价研究。移动生境选择研究表明,狍在移动的过程中偏好选择坡度小、距农田距离>500 m、远离道路、居民点和低海拔或较高海拔的区域;移动生境评价分析表明,移动适宜和次适宜生境面积之和为1318.16 km²,占研究区域面积的51.28%,当加入虎活动点影响因子后,狍移动适宜和次适宜生境面积之和为901.52 km²,适宜和次适宜生境面积之和减少了31.61%。狍卧息生境选择研究表明,水源、农田、道路和雪深是影响狍卧息的关键因素,其中雪深对狍卧息生境选择的贡献率达到70.13%;卧息生境评价表明,卧息适宜和次适宜生境面积之和为1243.77 km²,占研究区域面积的48.39%,当加入虎出现点因子后,适宜生境和次适宜生境面积之和减少了61.00%,仅为485.02 km²。研究认为,虎的出现对狍移动和卧息生境选择均产生影响,虎的活动及捕食行为可能会减少狍的活动范围和频次,狍远离虎活动区域卧息休息,压缩了狍适宜卧息的空间。     

Seasonal abundance and habitat use of bird species in and around Wondo Genet Forest,south‐central Ethiopia

The habitat use and seasonal migratory pattern of birds in Ethiopia is less explored as compared to diversity studies. To this end, this study aimed at investigating the patterns of distribution related to seasonality and the effect of habitat characteristics (elevation, slope, and average vegetation height) on habitat use of birds of Wondo Genet Forest Patch. A stratified random sampling design was used to assess the avian fauna across the four dominant habitat types found in the study area: natural forest, wooded grassland, grassland, and agroforestry land. A point transect count was employed to investigate avian species richness and abundance per habitat type per season. Ancillary data, such as elevation above sea level, latitude and longitude, average vegetation height, and percent slope inclination, were recorded with a GPS and clinometers per plot. A total of 33 migratory bird species were recorded from the area, of which 20 species were northern (Palearctic) migrants while 13 were inter‐African migrants. There was a significant difference in the mean abundance of migratory bird species between dry and wet seasons (t = 2.13, p = .038, df = 44). The variation in mean abundance per plot between the dry and wet seasons in the grassland habitat was significant (t = 2.35, p = .051, df = 7). In most habitat types during both dry and wet seasons, omnivore birds were the most abundant. While slope was a good predictor for bird species abundance in the dry season, altitude and average vegetation height accounted more in the wet season. The patch of forest and its surrounding is an important bird area for migratory, endemic, and global threatened species. Hence, it is conservation priority area, and the study suggests that conservation coupled with ecotourism development is needed for its sustainability.     

Habitat selection by ice-associated pinnipeds near St. Lawrence Island,Alaska in March 2001

Aerial surveys of ice-associated pinnipeds were conducted south of St. Lawrence Island in March 2001. The observed distributions of bearded seals (Erignathus barbatus), ribbon seals (Phoca fasciata), ringed seals (P. hispida), spotted seals (P. largha), and walruses (Odobenus rosmarus) were compared to the distributions of ice habitat types and benthic communities. Randomization tests were used to investigate habitat selection for each species. Both ringed seals and walruses preferred large ice floes (>48 m in diameter) that were common in the interior ice pack. Spotted seals favored smaller ice floes (<20 m in diameter) common near the ice edge, and bearded seals avoided large floes and preferred transitional habitat between small and large floes. Ringed seals also seemed to prefer areas with greater than 90% sea ice coverage, and bearded seals preferred 70–90% sea ice coverage while avoiding areas with greater than 90% coverage. All species, except spotted seals, were seen most frequently in a region of high benthic biomass, and randomization tests suggested that bearded seals actively selected that region.     

浙江清凉峰国家级自然保护区华南梅花鹿栖息地适宜性评价

理解环境因子对物种空间分布的影响,评价栖息地适宜性现状并预测潜在分布区,对野生动物的管理和保护具有重要意义。华南梅花鹿（Cervus pseudaxis）属国家I级重点保护野生动物,现仅分布于安徽、浙江、江西等狭小片区内。浙江清凉峰自然保护区千顷塘区域是华南梅花鹿的重要分布区,但其面积较小,严重限制了华南梅花鹿的种群发展,亟需对千顷塘及周边区域的栖息地质量进行评价,为华南梅花鹿的保护和野外放归提供科学依据。本研究利用红外相机监测千顷塘区域华南梅花鹿的分布,结合遥感等技术手段获得地形、植被、水源以及人为干扰等8种环境因子,利用MaxEnt构建华南梅花鹿栖息地适宜性模型,对以千顷塘为中心50 km×50 km的范围进行栖息地适宜性评价。研究结果表明,华南梅花鹿倾向于选择海拔1050-1240 m范围内,距道路100-900 m和距人口聚居区3200-3800 m的相对平缓地带。千顷塘区域华南梅花鹿栖息地保护较好,适宜栖息地面积为2224 hm2,占该区域39.1%。千顷塘周边适宜性较高的区域主要为位于其西南部约10 km的山区,该区域为华南梅花鹿提供了3253 hm2的潜在适宜栖息地。建议降低保护区千顷塘区域内的人为干扰,并在其西南部山区尝试开展圈养种群的野外放归工作,以促进其种群发展。     

大凉螈保护空缺分析与四川栗子坪国家级自然保护区保护成效评估

栖息地丧失和退化严重威胁全球两栖类动物的生存与繁衍,栖息地保护在两栖动物保育中具有高的优先性。大凉螈(Liangshantriton taliangensis)是国内外广泛关注的横断山区特有珍稀有尾类物种。结合大凉螈33个分布位点和9个环境变量数据,本文运用最大熵(MaxEnt)模型预测了大凉螈当前潜在适宜分布区,再根据现有自然保护地(5个国家级和9个省级)分布进行了保护空缺分析,同时,借助比例体重指数法(SMI)衡量了7个种群共218个个体的身体状况,比较了保护区内外种群间的差异,利用归一化植被指数(NDVI)识别了保护区内植被变化,据此对四川栗子坪国家级自然保护区的保护成效进行了评估。结果表明,(1)影响大凉螈分布的最主要环境变量为NDVI(贡献值34.33%)、最干月份降水量(贡献值26.81%)和海拔(贡献值20.92%);(2)大凉螈适宜生境主要集中在小相岭和凉山山系,占研究区域总面积的15.38%,现有自然保护地覆盖了大凉螈23.62%的适宜生境,仍有3760.91km²的保护空缺;(3)栗子坪保护区内雄性个体肥满度指数显著大于保护区外个体(t-tes...     

Conserving biodiversity in a changing world: land use change and species richness in northern Tanzania

Even though human induced habitat changes are a major driver of biodiversity loss worldwide, our understanding of the impact of land use change on ecological communities remains poor. Yet without such information it is difficult to develop management strategies for maintaining biodiversity in the face of anthropogenic change. To address this gap, we explored how land use practices impacted species richness in a mammalian community in northern Tanzania. Using camera traps, we estimated the number of mammalian species inhabiting three land use types subjected to increasing levels of anthropogenic pressure: (1) Tarangire National Park, (2) pastoral grazing areas; and (3) cultivated areas outside the park. Results showed that land use practice is correlated with different levels of species richness. Interestingly, mammal species richness was highest in the grazing areas and lowest in cultivated areas. When we focused our analyses on carnivores, we found little significant difference in species richness between the park and pastoral grazing areas, however, carnivore richness were significantly lower in the cultivated areas. We found no significant link between species body weight and presence in the three areas considered. Altogether, our results show that biodiversity conservation can be achieved outside national parks, with pastoral grazing areas holding a significant proportion of mammal communities; however increasing cultivation of pastoral rangelands may represent a major threat to mammalian communities.     

Home range area in the tortoise Testudo hermanni in relation to habitat complexity: implications for conservation of biodiversity

The tortoise Testudo hermanni is endangered by habitat fragmentation and loss in western Europe, where its high public profile and specific conservation projects make this a flagship species. Studies of movement in the peak reproductive season (June) showed that home ranges were substantially larger in France than in Greece. This difference was due to the intensity of use of the home range, not to the distance moved which was remarkably similar in the two areas. There was no sexual difference in home range area. The home range was therefore not large in France because of movement to nesting sites, but rather for utilization of the greater habitat complexity there. The need for reserves to include different vegetation types makes conservation of T. hermanni in France more difficult. Conversely, the need for large reserves increases its value as an umbrella species for conservation of biodiversity.     

木莲(Manglietia fordiana)的适生分布、影响因子与保护空缺研究

生境保护是维持生物多样性的基本途径，南方山地阔叶林维系着当地的生物多样性热点，而由于保护覆盖不足，保护效果亟待提高。以典型山地阔叶林树种木莲（Manglietia fordiana）为例，通过大尺度采集发生点，预测适生分布，获知影响其适生分布的关键因子。同时，以九连山种群进行案例研究，调查地方尺度下木莲植株的发生，了解其在山地地形、植被类型的选择特征。用MaxEnt构建最佳模型预测适生区，结果显示木莲适生区主体位于中国南部、西南部山地（如戴云山、南岭、罗霄山、武夷山等），向北延至大别山南坡，向西达横断山脉。木莲适生分布主要受最干月降水量（bio14，贡献率34.6%）、海拔高度（19.2%）、温度季节性变化标准差（bio4，15.6%）、最暖季降水量（bio18，12.0%）、最冷月最低温度（bio6，7.0%）影响，其60%适生概率范围或生态位bio14为30-55mm、海拔为400-1500m、bio18为500-800mm等。在适生区基础上，叠加考虑阔叶林分布，并选择其偏好海拔高度（>700m）提取获得木莲优先保护区，经与现有自然保护区叠加分析后，进行空缺识别，结果显示优先区保护覆盖为4.1%-6.0%，而高适生区保护覆盖也<10%（占比8.03%），覆盖比重较低。而沿<400m、400-700m、>700m海拔梯度显示>700m区域保护比重（8.7%）明显高于400-700m （4.4%）与<400（2.3%）组，说明前期保护区设计基本遵从优先区保护原则，能有效保护木莲高适生区。同样的，九连山保护区案例显示，当地木莲51.4%高适宜生境受到核心区的严格保护。研究结果表明，仍需在黄山-天目山区、苗岭东段、高黎贡山北段与南段、中越边界山区与广东西南山区6个空缺提高保护覆盖，通过建立新的自然保护区，优化当前保护网络，提高山地阔叶林的整体保护水平。     

砒砂岩区不同立地类型人工油松林下草本种群生态位特征及其环境解释

黄土高原砒砂岩区是我国水土流失最为严重的地区之一,油松(Pinus tabuliformis)是该区水土保持与水源涵养的优势乔木。以几种不同立地类型人工油松林为对象,应用Levins生态位宽度指数、Pianka生态位重叠指数和冗余度分析(RDA),研究林下草本群落生态位特征及其与环境的相互响应。结果表明:所调查的150个油松林下草本样方中,共发现31种草本植物,隶属于11科24属,阳性旱生植物居多。不同立地类型人工油松林下草本群落生态位特征不同,生态位宽度指数及生态位重叠指数均表现阳坡大于阴坡,平坡好于斜缓坡,但整体指数均较小,表明物种对环境资源利用程度较低,种间竞争度不大,群落处于相对稳定状态。通过对比典范对应分析(CCA)及冗余度分析(RDA),RDA排序更能较好揭示生态位特征与环境因素的关系,得出乔灌层郁闭度、土壤有机质、土壤含水率和坡度是林下草本群落生态位特征各异的主导环境因子。     

Exotic plant invasion in the highly degraded upland landscape of Hong Kong, China

Plant communities in the continental tropics have suffered less from exotic plant invasions than their oceanic island counterparts. Most studies have focused on near-pristine communities. By contrast, we examine the resistance of semi-natural continental plant communities in Hong Kong, which have been suffering from chronic and massive human impacts. We compiled a list of all naturalized non-native species recorded in Hong Kong and then sampled the plant communities for exotic species along roadsides, a stream through semi-natural vegetation, and in semi-natural vegetation away from both roads and streams on Tai Mo Shan, Hong Kong’s highest peak (957 m). Similar surveys were repeated in other areas of Hong Kong. More than 162 naturalized exotic plant species have been recorded in Hong Kong. On Tai Mo Shan, 29 exotic species were recorded in roadside vegetation, with the diversity but not percentage cover declining significantly with altitude. Fifteen exotic species were found along the stream, including two not found along the roadside. Only six exotic species were found away from roads and streams, all in unshaded areas disturbed by feral cattle. In all surveys, no exotics were found in closed woody vegetation or in open areas without feral cattle, except for one species. The shade-tolerant tropical Asian tree Syzygium jambos was found invading along some streamsides without anthropogenic disturbance. Despite centuries of massive human impacts, exotic plant invasions in Hong Kong are still largely confined to habitats that suffer from chronic human disturbance. Feral cattle promote invasion where people are absent, but this problem still seems potentially reversible. Only Syzygium jambos is of possible current conservation concern.     

土地利用/覆被变化对生物栖息地连接度的影响——以巩义地区黄鼬、蒙古兔和黄喉貂为例

土地利用/覆被变化通过改变生物栖息地而对物种分布产生影响。以河南省巩义市为研究区域,选取分布在该区域的哺乳动物黄鼬(Mustela sibirica)、蒙古兔(Lepus tolai)和黄喉貂(Martes flavigula)为目标物种,首先依据其生物特性和生态需求,确定了这3个物种的扩散能力;其次,基于景观连接度原理,分析了1990—2011年研究区土地利用整体变化和各类型变化情况,及其对单一物种和多物种栖息地连接度变化的影响。研究结果表明:(1)土地利用整体变化使得栖息地连接度增加,变化范围为22.22%—45.46%;(2)各土地利用类型变化对栖息地连接度的影响差异显著,连接度的升高和降低与栖息地斑块面积增加和减少密切相关;(3)基于多目标物种栖息地整体连接度空间分布图,确定了研究区目标物种保护的关键区域。     

Identifying climate refugia and its potential impact on Tibetan brown bear (Ursus arctos pruinosus) in Sanjiangyuan National Park,China

Climate change has direct impacts on wildlife and future biodiversity protection efforts. Vulnerability assessment and habitat connectivity analyses are necessary for drafting effective conservation strategies for threatened species such as the Tibetan brown bear (Ursus arctos pruinosus). We used the maximum entropy (MaxEnt) model to assess the current (1950–2000) and future (2041–2060) habitat suitability by combining bioclimatic and environmental variables, and identified potential climate refugia for Tibetan brown bears in Sanjiangyuan National Park, China. Next, we selected Circuit model to simulate potential migration paths based on current and future climatically suitable habitat. Results indicate a total area of potential suitable habitat under the current climate scenario of approximately 31,649.46 km², of which 28,778.29 km² would be unsuitable by the 2050s. Potentially suitable habitat under the future climate scenario was projected to cover an area of 23,738.6 km². Climate refugia occupied 2,871.17 km², primarily in the midwestern and northeastern regions of Yangtze River Zone, as well as the northern region of Yellow River Zone. The altitude of climate refugia ranged from 4,307 to 5,524 m, with 52.93% lying at altitudes between 4,300 and 4,600 m. Refugia were mainly distributed on bare rock, alpine steppe, and alpine meadow. Corridors linking areas of potentially suitable brown bear habitat and a substantial portion of paths with low‐resistance value were distributed in climate refugia. We recommend various actions to ameliorate the impact of climate change on brown bears, such as protecting climatically suitable habitat, establishing habitat corridors, restructuring conservation areas, and strengthening monitoring efforts.     

Distribution,abundance, and habitat use of introduced <Emphasis Type="Italic">Boa constrictor</Emphasis> threatening the native biota of Cozumel Island,Mexico

Species introductions are among the most pervasive types of disturbance, seriously affecting island biota and ecosystem dynamics. The management of introduced generalist species, which may live in a wide range of environmental conditions, can be particularly difficult and is a major challenge for the conservation of native insular species. Boa constrictor was introduced onto Cozumel Island, Mexico, in 1971. The introduction of this generalist predator has affected negatively the native species (many of them endemic to the island) on which the boa feed. It is important to determine temporal variation in boa abundance, the areas of the island in which boas live, and the vegetation types they use in order to develop management strategies to reduce boa pressure on the native biota. We used nocturnal road transect sampling and occasional boa encounters during field work, to estimate boa distribution, abundance and habitat use, taking into account its spatiotemporal patterns on Cozumel Island. This study confirms that Boa constrictor is well established, widespread, and abundant on the island. Our results show that boas are distributed throughout Cozumel, in all vegetation types and geographical regions. Overall, there were 0.11 ± 0.03 boa/10 km road transect. There were no significant spatiotemporal differences in boa activity (time of day) and abundance (monthly, seasonally, by vegetation types or regions of the island). According to the habitat use analysis, there were, however, fewer boas than expected in the subdeciduous tropical forest we sampled and in the central-northern region of the island, which coincide with areas inhabited by humans. There were more boas in areas uninhabited by humans, and there was a tendency towards a greater proportion of dead boas in inhabited areas and live boas in uninhabited areas. Cozumel boas are habitat generalists, which are affected by human induced mortality in inhabited areas. There is a vast area uninhabited by humans, with natural vegetation, on the island where boas have suitable habitats available for their continuous existence on Cozumel. This situation, and the adaptability of the boa, makes the control or eradication of this introduced species a critical conservation challenge.     

Restoration of European habitats in mainland Portugal,using commercial seed mixtures. Considerations for its management and conservation

Permanent mountain pastures include meadows and other perennial pastures of high ecological, economic, cultural and scenic value. Increasing desertification limits the maintenance and conservation of its biodiversity and the associated landscape mosaic. A restoration experiment in permanent high altitude grasslands in Beira Alta (Centre East (CE) mainland Portugal) was made, by sowing adequate cultivars of existing grass and legume species. The main objectives addressed were: (1) comparison of floristic composition between reference communities included in the previous habitats and the improved communities; (2) evaluation of the success of sowing adequate cultivars of autochthonous species; (3) evaluation of the establishment of target species in terms of the maintenance of floristic composition of reference. The experiment was carried out in 2014 on nine farms situated in Beira Alta (Guarda District) and the phytosociological method was applied in the floristic surveys. The sown species with highest percentage of soil cover were Trifolium subterraneum, Lolium multiflorum, Ornithopus sativus and Trifolium vesiculosum. In the priority habitat 6220 it was observed a re-establishment of many species in their original composition and a high cover of several cultivars of Trifolium subterraneum. These results highlight the importance of using cultivars of autochthonous species in the improvement of altitude pastures.