Wolves, elk, willows, and trophic cascades in the upper Gallatin Range of Southwestern Montana, USA

We summarized the status of wolves (Canis lupus), elk (Cervis elaphus), and woody browse conditions during the 20th century for the upper Gallatin elk winter range in southwestern Montana, USA. During this period, wolves were present until about the mid-1920s, absent for seven decades, and then returned to the basin in 1996. A chronosequence of photographs, historical reports, and studies indicated willows (Salix spp.) along streams became heavily browsed and eventually suppressed following the removal of wolves, apparently due to unimpeded browsing by elk. However, after wolf establishment in 1996, browsing intensity on willows lessened in some areas and we hypothesized that, at both a landscape and fine scale, browsing pressure reflects terrain configurations influencing predation risk (nonlethal effects), in conjunction with lower elk densities (lethal effects). We measured browsing intensity and heights of Booth willow (S. boothii) along 3000 m reaches of the Gallatin River and a tributary to examine the potential influence of wolf/elk interactions upon willow growth. Where the Gallatin Valley is relatively narrow (high predation risk), willows began releasing in 1999 and by 2002 were relatively tall (150–250 cm). In contrast, willow heights along a wider portion of the Gallatin Valley, along the open landscape of the tributary, and an upland site (all low predation risk) generally remained low (<80 cm). We identified terrain and other features that may contribute to the perceived risk of wolf predation, by elk for a given site. Although alternative mechanisms are discussed, changes in willow communities over time following wolf removal and their subsequent reintroduction were consistent with a top-down trophic cascade model involving nonlethal and possibly lethal effects. If similar top-down effects upon vegetation hold true in other regions of North America and other parts of the world where wolves have been extirpated, wolf recovery may represent a management option for helping to restore riparian plant communities and conserve biodiversity.     

Recoupling fire and aspen recruitment after wolf reintroduction in Yellowstone National Park,USA

We report on the recent growth of upland aspen (Populus tremuloides Michx.) thickets in northwestern Yellowstone National Park, USA following wolf (Canis lupus L.) reintroduction in 1995. We compared aspen growth patterns in an area burned by the 1988 fires to aspen growth patterns in an adjacent unburned area. Elk (Cervus elaphus L.) are the principal ungulates that use this area to meet foraging needs. Within a 2 m × 6 m belt transect established in each aspen thicket, we measured aspen densities and recorded annual browsing and height information on the three tallest post-1988 aspen stems. We found greater densities (p < 0.01) in the burned area relative to the unburned area. A decline in the percentage of stems browsed in the burned area began in 1997, with no measured browsing occurring since 2001. In contrast, the percentage of stems browsed in the unburned area began declining in 2002, with 41% of stems still being browsed in 2004. We hypothesize that the combined effect of fire and a subsequent decrease in herbivory following wolf reintroduction facilitated aspen growth. We further propose that, in addition to any changes in elk density in recent years, a recoupling of fire with increased predation risk from wolves may create a positive feedback loop that improves aspen recruitment.     

Patterns of lodgepole pine regeneration following the 1988 Yellowstone fires

In 1988, fires killed extensive lodgepole pine (Pinus contorta Dougl. ex. Loud) in Yellowstone National Park. This species bears both serotinous and non-serotinous cones, with the former most common in fire-origin stands of an even-aged character. Reconnaissance of burned stands indicated that former even-aged communities regenerated effectively. Others did not. The larger and more uniformly-sized seedling under formerly even-aged communities suggests primarily a single wave of regeneration there. Seedlings appeared to initiate to some degree over multiple years under other stands, but not sufficiently to make them well stocked. Four different regeneration pathways seem to characterize the natural reforestation of lodgepole pine following the 1988 fires. These include: (1) a dense, uniformly distributed cohort that will develop as a single-storied stand; (2) lodgepole pine islands that form over long periods around isolated seedlings; (3) a moderate to low density cohort that will gradually fill with multiple age classes over a protracted period; and (4) a cohort of only widely scattered single seedlings that initially form as small nearby tree islands, and may eventually converge into a more continuous stand with multiple age classes.     

珍稀野生花卉新秀——虎舌红

虎舌红是属于紫金牛科紫金牛属的一种亚灌木近草本植物，多次获得观赏花卉金奖。同时虎舌红还有极高的药用价值，全草有清热利湿、活血、止血止痛、祛腐生肌等功效，常用于治疗跌打损伤及祛风湿，亦可治疗结核咳血、肝炎等症。叶可外敷去疮毒。其繁殖方法可用播种繁殖，扦插繁殖，组织培养，还可以对其嫁接等，栽培上可地栽、盆栽、无土栽培技术和盆景造型栽培。管理上主要注意选择腐殖质，半荫的环境，其对水分要求不高，一般情况下不干不浇水。目前，通过人工选育出的新品种有黑虎舌、白虎舌、淡叶虎舌、矮叶虎舌、圆叶虎舌、红虎舌、绿虎舌等，对其观赏和药用价值以及快繁技术还需进一步开发。     

Linking wolves to willows via risk-sensitive foraging by ungulates in the northern Yellowstone ecosystem

After an absence of approximately 70 years, gray wolves (Canis lupus) were re-introduced into Yellowstone National Park in the mid-1990s. We studied the potential influence of wolf/ungulate interactions upon willow (Salix spp.) growth in the valleys of the Gallatin and Lamar Rivers, as well as Slough and Soda Butte Creeks, in the northern Yellowstone ecosystem. When we compared willow heights from photographs taken prior to 1998 (willows <2 m tall) with those taken in 2004, we found an increase in willow height for 22 of 42 sites within the study area. Based on comparisons of the chronosequence photos, since wolf introduction none of the 16 upland riparian sites showed an increase in willow height, while 22 of 26 of the valley-bottom riparian sites had willow height increases. In 2004, willow height exhibited a strong inverse relationship with the percentage of browsed stems (r = −0.81, p < 0.01, n = 42). Results of regressions for valley-bottom sites indicated that view distance, impediment distance, and the number of bison (Bison bison) flops were inversely related to willow height (p ≤ 0.02). Increased willow heights were not significantly (p = 0.18) related to patterns of moisture availability. Willow height increases documented in this study appear to have been at least partially due to behaviorally mediated trophic cascades involving wolves and ungulates, via a mechanism of predation risk. While willow release (i.e., increased height growth) within the study area is in a very early stage, results suggest potentially important indirect effects of a top carnivore in a terrestrial food chain that may aid in the restoration of riparian species and the preservation of biodiversity.     

广东车八岭国家级自然保护区野生观赏植物资源

广东车八岭国家级自然保护区有野生观赏植物124科254属399种，其中蕨类31科47属68种，裸子植物5科6属7种，被子植物88科201属324种。文章分析了车八岭国家级自然保护区野生观赏植物的基本特性和主要经济用途，并对资源保护和开发利用提出建议。     

广东省烂柯山自然保护区野生观赏植物资源调查

广东省烂柯山自然保护区共有野生观赏植物88科159属188种,其中蕨类植物15科25属29种,裸子植物4科4属5种,被子植物69科130属154种。分析了广东省烂柯山自然保护区野生观赏植物资源的基本特性和用途,并就其保护和开发利用进行了探讨。     

美国首座国家公园——黄石国家公园

美国黄石国家公园成立于1872年,1978年被联合国教科文组织列入《世界遗产目录》。此自然生态保护区地处美国中西部洛矶山山脉的熔岩高原上,属寒温带高原气候。由于数十万年前的火山喷发及流水冲蚀,园内形成惊人的地形、地貌;且园内森林茂密、绿草如茵,是全美最大的动物栖息地之一．园内采取特色的生态管理,目前已有超过6000万人...     

塔克拉玛干最后的守望者——野骆驼

看过《新疆经济报》记者石速5月11日的报道《阿尔金山三峰骆驼被残忍猎杀》一文后我十分痛心。据新疆罗布泊野骆驼国家级自然保护区管理中心的袁磊同志向记者反映：今年五一以前，该中心组织一批12人的科学考察巡护队，到若羌境内的阿尔金山地区考察野骆驼的春季活动情况时，却意外地发现了被猎枪枪杀的三具幼小的野骆驼尸横野外，现场让人目不忍睹。据调查确认这三峰小野骆驼是被偷猎者枪杀的。这不能不让我们感到震惊。     

塔克拉玛干最后的守望者——野骆驼

看过<新疆经济报>记者石速5月11日的报道<阿尔金山三峰骆驼被残忍猎杀>一文后我十分痛心.据新疆罗布泊野骆驼国家级自然保护区管理中心的袁磊同志向记者反映:今年五一以前,该中心组织一批12人的科学考察巡护队,到若羌境内的阿尔金山地区考察野骆驼的春季活动情况时,却意外地发现了被猎枪枪杀的三具幼小的野骆驼尸横野外,现场让人目不忍睹.     

野美太阳河

久居都市的人们在闲暇之余大多选择到郊野领略风景人文之美,这种旅游热潮随着经济社会的发展不断升温。在众多媒体的报道中,不难发现旅游已经从走马观花式的看景阶段逐渐过渡到了体验式的深度旅游。人们渴望在观景的同时,享受到大自然的丰富性和动植物世界的奇妙。在我国的云南,就有这样一个地方,被称为普洱人民心中不落的太阳,以丰富的动植物多样性和亚热带雨林风光吸引着一批批的游客。她就是云南太阳河国家森林公园。     

路边的野花

春天到了,百花开了。既然是百花,当然包括公园和街道旁的观赏花、自家精心培育起来的庭院花,以及山坡上、田野里和河流沼泽中自生自灭的各色野花。 野花可谓多矣,多得不胜枚举,多得不计其数。小路边的酢浆草花,颓壁后的野蔷薇花,石头缝里的矢车菊,河塘里随水飘浮的马蹄莲,篱笆上缠缠绕绕的牵牛花,更有那满山满岭的红杜鹃、打破碗花,空谷中的幽兰,崖畔上的野百合,还有无数名不见经传的各色野花,哪一种不是鲜活欲语,哪一朵不是灼灼娇姿!     

余姚野生兰科植物资源的分布与生境调查

采用查阅文献资料与实地调查相结合的方法,对余姚市野生兰科植物资源的分布与生境进行了深入调查。结果表明:余姚市共有野生兰科植物17属25种,生活型较单一,只有地生兰和附生兰2个类型。其中又以地生兰为主,计12属20种,但只有春兰、蕙兰、大花无柱兰3种的资源分布较广,且资源储量较大。各种野生兰科植物的分布与海拔、坡向、坡度、坡位、植被等生境因子具有显著的相关性:海拔在500 m以上的南部山区是余姚野生兰科植物的集中分布区,中坡、下坡和谷地,红壤、黄壤和粗骨土,针叶林、阔叶林和粗放经营的毛竹林为本区野生兰科植物的主要生境;兰花分布与乔木层优势树种没有明显相关性,但与灌木树种有较显著的相关性。余姚野生兰科植物资源已表现出了急剧萎缩的态势,急需开展就地与迁地保护。     

新疆阿尔泰额尔齐斯河河岸野生杨树的引种研究

通过对2006年春季引种的4种新疆阿尔泰额尔齐斯河河岸野生杨树的成活率、高生长及抗性的观测和分析,研究结果能为在本地区推广和应用这4种野生杨树提供参考.     

野美太阳河

久居都市的人们在闲暇之余大多选择到郊野领略风景人文之美,这种旅游热潮随着经济社会的发展不断升温。在众多媒体的报道中,不难发现旅游已经从走马观花式的看景阶段逐渐过渡到了体验式的深度旅游。人们渴望在观景的同时,享受到大自然的丰富性和动植物世界的奇妙。在我国的云南,就有这样一个地方,被称为普洱人民心中不落的太阳,以丰富的动植物多样性和亚热带雨林风光吸引着一批批的游客。她就是云南太阳河国家森林公园。大自然是奇妙的,她以特有的温润养育了万物。在太阳河,从激流到静水,从土壤到地表,从草丛到灌林,从林下到林冠,都生活着各式各样的动物。这里不仅沟河纵横,森林茂密,而且黑熊、野牛、绿孔雀、猕猴等保护动物都在此栖息,展示出一片亚热带雨林的野性之美。     

中山市五桂山野菜植物资源调查

据调查统计,中山市五桂山共有野菜植物44科69属81种,占全国总数的11.57%。其中蕨类植物4科4属5种,种子植物40科65属76种。文章分析了中山市五桂山的野菜植物资源特点,并就其开发利用提出了建议。