Retention of native vegetation within the plantation matrix improves its conservation value for a generalist woodpecker

The suitability of plantation monocultures for the conservation of forest animals is an issue under continous debate. The adaptability of forest dwellers and the forest management regime seem to play key roles. In this study, I investigated the habitat selection of a generalist bird, the great spotted woodpecker (Dendrocopos major), within a pine (Pine spp.) monoculture, as well as the importance of the native habitat features within the pine matrix for the species’ conservation. I compared 52 plots with woodpecker presence against 121 plots where the species was absent, as well as 68 nest-trees against 90 random ones. Regression analyses were used to investigate the habitat attributes involved in the habitat selection. Although the great spotted woodpecker is considered a generalist forest dweller, it shows a marked habitat selection. Based on presence/absence records, the woodpecker prefers well-forested patches with high levels of tree diversity and with good coverage of a secondary species such as the strawberry tree (Arbutus unedo). To excavate their nests, woodpeckers select large trees in patches where other trees are also larger, rejecting patches with a high number of small trees. The most striking conclusion from this work is the preference shown for native trees, especially Portuguese oaks (Quercus faginea), as nest-trees. This is noteworthy because native trees are smaller and they are surrounded by smaller trees than pines. These findings support that woodpecker conservation benefits from an increase of habitat heterogeneity, particularly by the retention of native woodland patches within the plantation matrix.     

Habitat prediction model for three-toed woodpecker and its implications for the conservation of biologically valuable forests

We studied habitat selection of three-toed woodpecker (TTW) in relation to forest structural variables, habitat types and hydrological conditions in north-eastern Poland. Based on known locations of 34 breeding pairs and the data on location of forest areas with high conservation value (referred to as Biologically Important Forests), we created a habitat prediction model for TTW using a Maxent algorithm. We found that this species most often selected breeding sites characterized by high contribution of old-growth stands with uneven vertical structure and considerable amount of very old trees of previous generations, as well as boreal spruce-dominated bogs and riverine forests. Such sites were preferred regardless of their actual protection status, which leads to the following conclusion: although existing forest reserves are very important to three-toed woodpecker, suitable habitats with similar characteristics can still be found outside protected areas and are also utilized by the species. However, such sites outside reserves are threatened by fragmentation due to timber extraction. Therefore it is recommended to protect these sites by either including them into existing reserves or putting them under special management schemes.     

A landscape and policy perspective on forest conversion: Long-tailed tit (<Emphasis Type="Italic">Aegithalos caudatus</Emphasis>) and the allocation of deciduous forests in southern Sweden

As resources allocated specifically for conservation are limited, there is a need to ensure conservation policy initiatives lead to effective conservation outcomes. In this study, we investigated the potential conservation benefits from alternative spatial allocations of old deciduous stands to a landscape dominated by coniferous production forests owned primarily by non-industrial private forest owners. As a target species, we used the long-tailed tit (Aegithalos caudatus), a species associated with deciduous forests and known to be sensitive to isolation. We used a previously published model based on empirical data on the occurrence of this species, to assess the probability of occurrence of the bird in a 4,000 km² area in southern Sweden for which we possess detailed spatial GIS data (kNN data) of tree species composition and age. We assessed alternative scenarios where old deciduous forest was allocated with or without respect to distance from existing old deciduous forests. Due to the long-tailed tit’s habitat requirement increasing the amount of old deciduous forests close to existing habitats was the most effective strategy. However, the potential advantages of this strategy may in fact be overturned in favor of the other scenarios if ownership structures and probable uptake rates of policy initiatives are also considered. If a policy initiative is targeted toward owners with properties in close proximity to existing suitable habitat, when compared to if all forest owners are targeted, a higher proportion of owners is needed to participate in order to achieve the same degree of habitat creation for the species. Here, we discuss the potential benefits for effective conservation policy formulation from integrating spatially explicit datasets and detailed ecological knowledge with land-ownership structures and policy uptake scenarios.     

人类干扰对甘肃麻家寺保护站鸟类群落的影响

2004年11月~2005年1月,在兴隆山麻家寺保护站的6种生境(灌木、阔叶林、混交林、针叶林、农田和人工林)中共记录鸟类25种。鸟类物种总数以灌丛和人工林最高,均为15种。阔叶林最低,为10种。鸟类多样性最高的是灌丛,最低的是阔叶林。各种生境中的鸟类组成和优势物种差异较大,建议每种生境均保持一定面积,以便保护鸟类物种多样性。     

Estimating breast height diameter and volume from stump diameter for three economically important species in Turkey

Abstract

In Fennoscandia, the concept of woodland key habitats has become one of the key concepts when defining hotspots for forest biodiversity. There is a serious lack of studies, however, in which the diversity value of the assumed key habitats has been assessed for any groups of organisms. The aim of this study was to investigate whether the woodland key habitats as defined in the Finnish Forest Act can be advocated as diversity hotspots for polypores, a group of wood-decaying fungi including several red-listed species and species used as indicators for conservation value of forests. The study area was situated in the southern boreal zone, in eastern Finland. In total, 72 woodland key habitat sites representing six different habitat types, and 12 production forest sites as controls were investigated for their polypore assemblages. A total of 2077 records of 93 species was made, of which only 17 records of nine species were red-listed. On average, key habitats hosted more species than control forests, but of the six habitat types, only fresh and mesic–moist herb-rich forests differed significantly in species number from the control forests. Compared with control forests, key habitats can maintain rich polypore flora but, because of the low number of red-listed species found, they are likely to be of little help in the conservation of threatened polypores.     

基于MaxEnt模型的白水河国家级保护区有蹄类保护动物生境适宜性评价

通过MaxEnt模型对白水河国家级自然保护区4种有蹄类保护物种进行生境适宜性评价,研究结果如下:(1)20次重复后斑羚、鬣羚、林麝、羚牛的训练集AUC值分别为0.962、0.947、0.924和0.945;(2)斑羚、鬣羚、林麝、羚牛得适宜栖息地分别占保护区总面积的14%、27%、25%、24%,次适宜栖息地占保护区总面积的27%、19%、35%、34%,不适宜栖息地占保护区总面积59%、54%、40%、42%;(3)对斑羚贡献最大的3个环境因子是坡向、坡度和落叶灌丛,对鬣羚贡献最大的3个环境因子是竹林、栽培竹林和落叶灌丛,对林麝贡献最大的3个环境因子是坡向、落叶灌丛和竹林,对羚牛贡献最大的3个环境因子是坡向、竹林以及落叶阔叶林。     

兴隆山国家级自然保护区鸟类群落初报

通过对兴隆山自然保护区阔叶林、混交林和针叶林鸟类群落结构的调查，结果表明：混交林中鸟类物种数和鸟类物种多样性最高，阔叶林最低。其中，山雀科和鳾科在阔叶林中占优势，而柳莺亚科在混交林和针叶林中占优势。提出了保护区每种生境都应保持一定面积，以便保护该地区鸟类物种多样性的建议。     

Response of woodpeckers to changes in forest health and harvest: Implications for conservation of avian biodiversity

Woodpeckers (family Picidae) merit specific monitoring and management efforts, both as keystone/facilitator species and as indicators of forest condition. Recent studies indicated that species richness of woodpeckers was correlated with richness of all forest birds, thus suggesting potential exists for management practices that can address needs of woodpeckers in particular and other forest birds in general. We used data from a long-term study (1995–2008) from forest sites in the interior of British Columbia to evaluate how abundances of seven woodpecker species varied with habitat variables previously identified as associated with forest bird richness. We found that tree species richness had either a neutral or positive effect on the abundance of all woodpecker species, whereas abundances of most woodpecker species tended to be lower in stands with high densities of lodgepole pine. Abundances of most woodpecker species were positively correlated with density of beetle-killed pines. Relative to control sites, higher densities of most woodpecker species were found at harvested sites where most trembling aspen and large Douglas-fir trees had been retained. Therefore, management strategies that favour a mixture of tree species, with particular attention to retention of aspen, should safeguard populations of most woodpecker species. Abundances of individual woodpecker species were weakly but positively inter-correlated before the beetle outbreak, and less so during and post-outbreak. It thus appears that no strong trade-offs exist among woodpecker species. These results, combined with previously identified positive correlations between woodpecker and forest bird richness, indicate woodpeckers can be managed as a suite for the purpose of managing avian biodiversity as a whole.     

Butterfly distribution in fragmented landscapes containing agroforestry practices in Southeastern Brazil

Agroforestry practices, such as Shaded Coffee and Homegardens, may provide habitat for forest butterflies and contribute to their conservation in fragmented agricultural landscapes. To determine the influence of agroforestry practices in an agricultural mosaic, the distribution of fruit-feeding butterflies was studied using a systematic approach that compared butterfly species richness in six land-use practices (Eucalyptus [Eucalyptus spp.], Shaded Coffee, Homegardens, Secondary Growth, Pastures, and monocultures of Cassava [Manihot esculenta] and Sugarcane [Saccharum officinarum]), and in natural habitat (secondary Forest Edge and Interior) in two study areas (agricultural landscapes). In each study area, Van Someren-Rydon butterfly traps were placed as a grid every 150 m, creating quadrants of 2.2 and 2.4 km² that encompassed the different land-use practices. Land-use, plot area, number of traps and distance to the forest were set as covariates to compare species richness values. Butterfly species composition was compared using linear discriminant analysis (LDA). With the exception of Pastures, Cassava and Sugarcane, significant differences were not identified between the rest of the agricultural land-use practices and the forest habitats (edge and interior). The species composition in the agricultural practices was however, different to that found in forest habitats. Overall, Shaded Coffee practices that represent long-term mixed tree and crop stands have a better potential of conserving forest butterfly species compared to monoculture practices.     

Long-term changes in two boreal landscapes with different management histories

Abstract

Forest fragmentation increases the amount of edge habitats in landscape. Despite the profound ecological influences that edges may have, the patterns and processes of edge formation have largely remained unexplored. The aim of this study was to find answers to three questions: (1) How have the landscape structure and composition, as measured by different successional stages, changed over a period of about 50years in forested landscapes in southern Finland? (2) What are the differences in the amount of edge and interior habitat between successive years? (3) How does the forest ownership, state or private, affect the prevalence of edges? Digitized aerial photographs taken in 1941 and 1944 (period1), 1969 (period2) and 1997 (period3) were used to study the prevalence of different successional stages, area of interior mature forest and edge habitats in two nearby 10km² forest areas with private and state ownership, respectively. The forest composition was similar in the two forest areas, with mature forests being replaced by younger development stages. The area of interior mature forest decreased dramatically from period1 to period2. Assuming an edge width of 100m, the proportion of edge habitat increased from 30% to 61% in the state forest and from 26% to 76% in private forest. The detected changes and their possible consequences to species suggest that management of different types of edges and converging edges should receive considerable attention in the future.     

Distribution patterns of acorns after primary dispersion in a fragmented oak forest and their consequences on predators and dispersers

Forest fragmentation affects seed production, but little is known about how seeds are distributed in fragmented forests after primary dispersion and how this affects their interactions with other organisms. This study addressed these issues in a fragmented oak forest of Quercus laeta where four habitat types were recognized: interior and edge of patches, deforested matrix around patches, and an abandoned field. Areas and distances to the abandoned field were measured for 40 patches, and acorns were sampled in all habitats. Only samples from the interior and edge of patches had acorns, which were classified as aborted, viable, and parasitized by insects or fungi. Acorns in all these classes were regressed against patch area and distance to the abandoned field. Field experiments were also conducted to determine whether acorn removal rates varied across habitats. Aborted acorns within patches were not related to area or distance, but they decreased with increasing values of both variables at patch edges. Within patches, viable acorns were positively related to increases in area and distance, while the converse occurred for insect-damaged acorns; fungal-infested acorns were not related to patch variables in this habitat. Complex interactions between area and distance explained how acorns in these classes were distributed across patch edges. Acorn removal was higher within patches and their edges when compared to human-disturbed habitats; both mice and birds were identified as potential acorn dispersers. These results suggest that forest fragmentation affects acorn-mediated processes and that this may influence the recovery of patch connectivity in the landscape.     

Comparing regional forest policy scenarios in terms of predicted suitable habitats for the Siberian flying squirrel (Pteromys volans)

Forecasting the potential impacts of forest policies on species of special conservation value is a prerequisite for safeguarding forest biodiversity. In this study, regional forest policy scenarios were compared in terms of predicted habitats suitable for the Siberian flying squirrel (Pteromys volans). To derive both patch- and landscape-scale models to predict species presence in a forest stand, species occurrence data from a systematic field survey covering the whole distribution area of the flying squirrel in Finland and Multi-Source National Forest Inventory data were combined. Then, the Finnish forestry model MELA and the derived occupancy models were applied to predict the quantity of suitable habitats for flying squirrels in three different 50-year policy scenarios. The results confirm that increasing the utilization of felling potential from the level of business-as-usual to the level stated as policy targets in regional forest programs decreases the amount of suitable habitat in the future. However, regional forest programs had a less drastic impact on habitats than maximum sustainable removal, except in two regions. It should be noted that the occupancy models seemed to fail on sites that experts deem to be most suitable for the species. Obviously, there are other factors than forest management affecting presence.     

Relative contribution of edge and interior zones to patch size effect on species richness: An example for woody plants

In order to understand the capacity of habitats to conserve species, many authors have searched for a species–area relationship (SAR) to evaluate the effect of patch size on species richness in habitat fragments. However, a range of different processes may underlie or obscure this relationship. For woody plant species in forest fragments, as for other taxa, considering forest edges separately in the investigation of SAR is particularly relevant. The objective of our study was to evaluate edge influence on SAR in a fragmented forest landscape in south-western France. To achieve this objective, we considered SAR in two separate spatial portions of the forest fragment: the edge and the forest interior. We also considered SAR for different ecological groups of species based on their shade tolerance and their mode of dispersal, as species can respond differently to habitat reduction depending on their ecological characteristics. In 40 woodlands in an agricultural landscape, we observed the presence/absence of all woody species along parallel walking transects 20-m wide to inventory the total number of species in each woodlot. Vegetation surveys resulted in the identification of 53 woody species, with a total of 23 trees and 30 shrubs, and a number of species per woodlot ranging from 18 to 44. The species richness found in a given woodlot was significantly correlated with its area. When considering the edge and the interior parts of the woodlot separately we found a steeper increase in species richness with area for the part we considered as the edge, compared with the increase found in the interior part of the forest. Our results confirm the contribution of forest edge to forest fragment SAR. Results also underlined the importance of two additional processes that may contribute to SAR: a possible extinction debt of shade-tolerant species in forest edge zones and colonisation by light-demanding species in forest interior zones probably due to disturbances. This approach underlines the importance of taking the edge effect into account when studying the influence of patch size on species richness and the dynamic of species richness pattern.     

Habitat selection of Guizhou golden monkey （Phinopithecus roxellanae brelichi）in Fanjing Mountain Biosphere Reserve, China

Guizhou golden monkey (Phinopithecus roxellanae brelichi) is a peculiar, rare and endangered species. It is distributed most narrowly and requires a rigorous habitat. In this study the habitats of Guizhou Golden Monkey were divided into three habitats: most suitable habitats, suitable habitats and marginally suitable habitats. The characteristics of the vegetation community, environmental factors and extreme environmental factors in the three habitats were systematically analyzed. The seasonal activity rule, activity area and the food characteristic of Guizhou golden monkey were also study at the same time. The results indicate that the evergreen and deciduous broadleaf mixed forest is the optimal living vegetation community for Guizhoug olden Monkey, and the suitable annual temperature is 8-15℃, the extremely lowest temperature is -2.5℃, the extremely highest temperature is 25℃, and the optimal living altitude is 1500-1700 m. In the same area, the higher the vegetation diversitythe more suitable it is for the life of Guizhou golden monkey. Temperature and food are the main habitat factors in determining the activity scope of the guizhou golden monkey community. The Altitude, temperature and the characteristics of the vegetation community are the main limitina factors for habitat selection.     

Additions of landscape metrics improve predictions of occurrence of species distribution models

Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models.     

Multi-scale nest-site selection by black-backed woodpeckers in outbreaks of mountain pine beetles

Areas of mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks in the Black Hills can provide habitat for black-backed woodpeckers (Picoides arcticus), a U.S. Forest Service, Region 2 Sensitive Species. These outbreaks are managed through removal of trees infested with mountain pine beetles to control mountain pine beetle populations and salvage timber resources. To minimize impacts to black-backed woodpeckers while meeting management objectives, there is a need to identify characteristics of these areas that support black-backed woodpeckers. We examined the habitat associations of this species nesting in areas of beetle outbreaks in the Black Hills, South Dakota in 2004 and 2005. We used an information theoretic approach and discrete choice models to evaluate nest-site selection of 42 woodpecker nests at 3 spatial scales—territory, nest area, and nest tree. At the territory scale (250 m around nest), availability and distribution of food best explained black-backed woodpecker selection of beetle outbreaks versus the surrounding forest. Selection at the territory scale was positively associated with densities of trees currently infested by mountain pine beetles and indices of wood borer (Cerambycidae and Buprestidae) abundance, and was greatest at distances of 50–100 m from the nearest patch of infestation. At the nest-area scale (12.5 m radius around the nest), densities of snags positively influenced nest-area selection. Finally, at the nest-tree scale, aspen (Populus tremuloides) and 3–5-year-old ponderosa pine (Pinus ponderosa) snags were important resources. The association between abundant wood-boring insects and black-backed woodpeckers creates a difficult challenge for forest managers. In the absence of fire, areas of beetle outbreak might serve as the only substantial source of habitat in the Black Hills. Regulating insect populations via salvage logging will reduce key food resources to black-backed woodpeckers during nesting. Therefore, given the relatively infrequent occurrence of large-scale fire in the Black Hills, management should recognize the importance of beetle-killed forests to the long-term viability of the black-backed woodpecker population in the Black Hills.     

Modelling and mapping the suitability of European forest formations at 1-km resolution

Proactive forest conservation planning requires spatially accurate information about the potential distribution of tree species. The most cost-efficient way to obtain this information is habitat suitability modelling i.e. predicting the potential distribution of biota as a function of environmental factors. Here, we used the bootstrap-aggregating machine-learning ensemble classifier Random Forest (RF) to derive a 1-km resolution European forest formation suitability map. The statistical model use as inputs more than 6,000 field data forest inventory plots and a large set of environmental variables. The field data plots were classified into different forest formations using the forest category classification scheme of the European Environmental Agency. The ten most dominant forest categories excluding plantations were chosen for the analysis. Model results have an overall accuracy of 76%. Between categories scores were unbalanced and Mesophitic deciduous forests were found to be the least correctly classified forest category. The model’s variable ranking scores are used to discuss relationship between forest category/environmental factors and to gain insight into the model’s limits and strengths for map applicability. The European forest suitability map is now available for further applications in forest conservation and climate change issues.     

基于InVEST模型的北京市延庆区自然保护地生境质量评估

采用InVEST模型,选取生境质量和生境退化风险两个指标,分析北京市延庆区生境质量空间分布特征;通过莫兰指数与ArcGIS软件结合,揭示两个生境指标的冷热点覆盖区;探究生境质量、生境退化风险与不同类型自然保护地间的关系。研究结果表明：延庆区生境质量东北部、西北部和东南部较高,西南部部分区域生境质量较低,生态退化风险从东北向西南呈升高趋势,各类自然保护地生境质量指数均高于0.9,且均高于全区均值(0.834 2);自然保护地内生境热点较少,生境退化风险热点主要集中在西南部城区,东北和东南部也有零星分布;不同类型保护地之间生境退化风险存在一定差异,其中湿地公园退化风险高于其他类型,需要强化对湿地公园的规划和管理,减少人为活动的干扰。     

Hazel Grouse occurrence in fragmented forests: habitat quantity and configuration is more important than quality

Forest fragmentation has led to a decline in the population of many forest specialists, especially those with limited dispersal abilities. However, some of these species also occur in fragmented forests, and their response to fragmentation is crucial to understand the impact of this process in maintaining forest biodiversity. The objective of this study was to investigate the effects of habitat quality, quantity and configuration on the occurrence of Hazel Grouse as the model species. Studies were performed in the Carpathian Foothills (900?km², 15?% forested). Between 2000 and 2010, Hazel Grouse were detected in 25 out of 53 forest patches with high repeatability over time. Among the indices of habitat quality, the most important factors were the presence of bilberries, clearings and pioneer trees. Greater number and length of valleys also had a positive effect on the occurrence of grouse. All habitat quantity and landscape configuration variables influenced the presence of grouse positively (related to forest connectivity) or negatively (related to forest isolation). Among the explanatory variables considered, habitat quantity and landscape variables were much more important in explaining the occurrence of Hazel Grouse than variables related to habitat quality. The study shows that habitat acreage and its connectivity are crucial for the conservation and management of Hazel Grouse populations in fragmented landscapes, and therefore, it is necessary to sustain wooded corridors between larger forest patches.     

The response of small mammals to natural and human-altered edges associated with Afromontane forests of South Africa

An increase in edge area reduces the effective size of habitat fragments and thus the area available for habitat-interior specialists. However, it is unclear how edge effects compare at different ecotones in the same system. We investigated the response of a small mammal community associated with Afromontane forests to edge effects at three different habitat transitions: natural forest to grassland (natural edge, structurally different vegetation types), natural forest to mature plantation (human-altered edge, structurally similar vegetation types) and natural forest to harvested plantation (human-altered edge, structurally different vegetation types). We predicted that edge effects should be less severe at natural ecotones and at similarly structured contiguous vegetation types than human-altered ecotones and differently structured contiguous vegetation types, respectively. We found that forest species seemed to avoid all habitat edges in our study area. Surprisingly, natural edges supported a less diverse small mammal community than human-altered forest edges. However, edge effects were observed deeper into native forests surrounded by mature alien plantations (and more so at harvested plantations) than into native forests surrounded by native grasslands. The net effect of mature plantations was therefore to reduce the functional size of the natural forest by creating a larger edge. We suggest that when plantations are established a buffer zone of natural vegetation be left between natural forests and newly established plantations to mitigate the negative effects of plantation forestry.