Birds In Plantations Research Articles

Sharing land via keystone structure: Retaining naturally regenerated trees may efficiently benefit birds in plantations.

Meeting food/wood demands with increasing human population and per-capita consumption is a pressing conservation issue, and is often framed as a choice between land sparing and land sharing. Although most empirical studies comparing the efficacy of land sparing and sharing supported land sparing, land sharing may be more efficient if its performance is tested by rigorous experimental design and habitat structures providing crucial resources for various species-keystone structures-are clearly involved. We launched a manipulative experiment to retain naturally regenerated broad-leaved trees when harvesting conifer plantations in central Hokkaido, northern Japan. We surveyed birds in harvested treatments, unharvested plantation controls, and natural forest references 1-year before the harvest and for three consecutive postharvest years. We developed a hierarchical community model separating abundance and space use (territorial proportion overlapping treatment plots) subject to imperfect detection to assess population consequences of retention harvesting. Application of the model to our data showed that retaining some broad-leaved trees increased the total abundance of forest birds over the harvest rotation cycle. Specifically, a preharvest survey showed that the amount of broad-leaved trees increased forest bird abundance in a concave manner (i.e., in the form of diminishing returns). After harvesting, a small amount of retained broad-leaved trees mitigated negative harvesting impacts on abundance, although retention harvesting reduced the space use. Nevertheless, positive retention effects on the postharvest bird density as the product of abundance and space use exhibited a concave form. Thus, small profit reductions were shown to yield large increases in forest bird abundance. The difference in bird abundance between clearcutting and low amounts of broad-leaved tree retention increased slightly from the first to second postharvesting years. We conclude that retaining a small amount of broad-leaved trees may be a cost-effective on-site conservation approach for the management of conifer plantations. The retention of 20-30 broad-leaved trees per ha may be sufficient to maintain higher forest bird abundance than clearcutting over the rotation cycle. Retention approaches can be incorporated into management systems using certification schemes and best management practices. Developing an awareness of the roles and values of naturally regenerated trees is needed to diversify plantations.

ЗВОЛОЖЕННЯ, ЯК ФАКТОР СТРУКТУРНОЇ ОРГАНІЗАЦІЇ НАСЕЛЕННЯ ПТАХІВ ДЕРЕВНИХ НАСАДЖЕНЬ БІОСФЕРНОГО ЗАПОВІДНИКА "АСКАНІЯ-НОВА"

<p>The influence of different humidification types towards appearance of forest vegetation conditions on spatial organization of birds in the wood stands is analyzed. Population density, coefficient of occurrence, and informative connection with six types of soil humidification are given for 53 bird species. The informative estimation of every humidification type is determined for every bird species. Thereby it is definitely a contribution of every gradation of edaphic factor to the structural genesis of dendrophilous bird communities. The strongest informative connection between humidity gradients and the avifauna structure of the wood stands is available in dry edaphotopes for margin representatives and fresh one for typical forest species. These two humidification types play a start function in the structural genesis of some blocks of dendrophilous bird communities per se. It is determined that change of bird species of forest-steppe faunogenetic complex by species from Nemoral complex undergoes in most cases on the border of the gradient between fresh and humid edaphotopes.</p> <p>For 53 species of birds from dendrophilous complex is was revealed that the importance of different levels of soil moisture has a different impact in shaping of the modern structure dendrophilous avifauna. Dry and especially drily edaphotopes determine the spatial structure of the species that are of forest-steppe origin and belong to the representatives of the optional component of dendrophilous bird communities. Wet edafotopes are involved in the formation of the spatial structure of species of predominantly immoral origin and relate to the obligate component of representatives of dendrophilous bitd comminities.</p> <p>Gradient wetting of edaphotopes on the verge of ‘linked’/’fresh’ is restructuring for the bird communities. It takes an optional replacement red communists feature to obligate. Stands rather dry and fresh items currently being the most active formation of the spatial structure of bird communities. In relation to the stands for dryish soil compaction observed populations of species that nest there. The fort stands on fresh soil tend to be the emergence of new species for nesting communities. Despite the small area and the uneven spatial arrangement of belts that are caused the effect of irrigation, there are some places of nesting of small belts for species that occur there only because of the increased level of humidity and the presence of open temporary ponds used by waterbirds. These belts have a ‘hunchback’ profile, caused by the constant flooding, and as a result - a tall and dense stands in the center of the forest belt. Formation of watering places is a separate factor that attracts birds in plantations. This phenomenon is described in detail in the literature. Significant structural adjustment of reserve stands caused by the age and condition of vegetation diversity management techniques, moreover the "island" effect becomes characteristic is fewer birds – like dendrophilous. Under present conditions, it does not describe the dendrophilous features for the bird communities in general. Only a few species possess the most biocenotical selectively retain the characteristics inherent to the "island”type populations. The biosphere reserve "Askania Nova" represents the diversity loam with varying degrees of moisture and salinity. The most common are dark chestnut soils in the north of the reserve bordering the southern black soils. Most belts representing tree plantation reserve, located in dark chestnut soils with low humus content in loess loam. Also, the composition of the physical and chemical properties of soil contributes to some zoogenic factors. In relation to the spatial distribution of birds in the reserve, one of the leading factors of the spectrum is the nature of hydration. Directly or through the woody vegetation it determines the nature of the spatial distribution of bird dendrophilous complexes. Relatively high diversity was registered due to the variety of types of moisturizing various irrigation methods for soils. Protected steppe area, which is an indigenous prairie biogeocoenoses and buffer zone of the reserve devoid of any irrigation. Dendroparks and the area of a typical land reserve is the only territory where we registered waterbirds in artificial plantations. This phenomenon is described in detail in the literature.</p> <p>Artificially created temporary pond (puddle) significantly enrich nesting avifauna in tree plantations. Internal cessation of irrigation, which contirubute to the shift of bird species from the category like "water" in fresh and significantly intensifies adjustment in quantitative and qualitative composition of the breeding avifauna of the reserve. Changes among other options moisturizing shades avifauna respond usually quantitative structure rearrangements of existing species.</p> <p><em>Key words: typology, </em><em>humidification, gradient of factor, structural genesis, biosphere reserve.</em></p>

Bird communities in small native remnants of contrasting understorey condition within bluegum plantations

The area of agricultural land converted to commercial plantations across Australia has expanded rapidly and includes large areas (0.5 M ha) planted to Tasmanian Blue Gum (Eucalyptus globulus) (National Forest Inventory 2005). The outcome of this for biodiversity conservation is still being evaluated. In general, plantations support more native faunal species than farmland, but less than native vegetation remnants (Lindenmayer & Hobbs 2004). However, the value of small remnants (<5 ha) to native fauna in plantations is unclear. For birds in plantations, small remnants may be important ‘stepping stones’ or provide small, high quality habitat patches within a larger habitat mosaic (Fischer & Lindenmayer 2002), especially for species that can exploit resources within plantations (Loyn et al. 2007). However, degradation by weed invasion can reduce the value of small remnants for bird conservation (Loyn 1987). A better understanding of the biodiversity value of small remnants is needed given that many plantation companies operating under forest product certification are now formulating approaches to managing biodiversity within their estates. Therefore, we examined bird communities in Tasmanian Blue Gum plantations (hereafter called bluegum plantations’), contrasting plantation areas with small remnants with predominantly exotic, and native, understoreys. Implications for remnant management and monitoring are discussed.

Enhancing Avifauna in Commercial Plantations

The occurrence of fauna in commercial plantations is often associated with structural complexity. Through a meta-analysis, we tested whether the structural complexity of plantations could enhance bird species assemblages and whether bird assemblages respond differently depending on taxonomic affiliation, body size, and diet. Our analyses included 167 case studies in 31 countries in which bird assemblages in forests and plantations were compared and 42 case studies in 14 countries in which bird assemblages in plantations of different structural complexity were compared. Species richness, but not abundance, was higher in forests than in plantations. Both species richness and abundance were significantly higher in complex than in structurally simple plantations. Taxonomic representation and body size did not differ between forest and plantations, except that there were fewer insectivorous birds in plantations than in forests. In the comparison of simple versus complex plantations, abundance of all taxonomic and dietary groups was higher in complex plantations. Body size did not affect bird species richness or abundance. Independent of the type of plantation, bird richness and abundance were greater in structurally complex plantations. Enhancing the structural complexity of plantations may mitigate their impact and offer habitat for some native species.

Hybrid poplar plantations in a floodplain have balanced impacts on farmland and woodland birds

Hybrid poplar plantations are increasing worldwide and are often accused of impoverishing bird communities. We conducted 124 bird point counts in a landscape where plantations, semi-natural forests and farmland occupied similar surface areas. As expected, birds occurred at higher densities in areas dominated by forests than dominated by plantations, mostly due to the scarcity of late-successional forest birds in plantations. Contrary to expectations, bird communities were the poorest in farmland dominated areas and the most specialised in areas dominated by young plantations. Indeed, many grassland species, including some of conservation concern in Europe, frequently used young plantations. However, plantations have probably depleted grassland bird communities by fragmenting open areas, while playing a limited positive role on forest species. Total length of unpaved roads had a positive effect on community specialisation index, while total length of paved roads and mean forest/plantation patch size played no role. Bird density increased with the development of the understory vegetation in mature poplar plantations. We conclude that poplar should not be planted at the expense of areas of high conservation value; in other cases, they may increase the overall diversity of bird communities. At the plantation scale, we advocate stopping understory removal as soon as possible and maintaining old trees and hedgerows alongside or within plantations to provide suitable breeding habitats for bird species that may be foraging in the plantations.

Avian Resource Use in a Caribbean Pine Plantation

I studied resource use by birds in a Caribbean pine (Pinus caribaea) plantation in Luquillo Experimental Forest, Puerto Rico, from 1981 to 1986. I used multivariate analyses to quantify and provide a classification of foraging relationships among bird species. The analysis of food-searching behavior by birds indicated that resource use was closely associated with vegetation physiognomy. The presence of specific kinds of vegetation was important in determining the presence and abundance of some bird species. Frugivores and nectarivores foraged in understory flowering and fruiting shrubs. Among insectivores, foliage-gleaners were found mainly in the canopy and hoverers were concentrated in the understory. Dead hanging leaves and vine thickets provided important foraging substrates for some species. Forest managers can improve habitat for birds in plantations by providing habitat heterogeneity through maintenance and encouragement of understory vegetation diversity, vine thickets, and native upperstory trees. J. WILDL. MANAGE. 52(2):274-279 Information on the impacts of land management practices on neotropical birds, and particularly the changes that occur when heterogenous tropical forest ecosystems are converted to pine plantations, is limited. In Australia, exotic pine (Pinus radiata) plantations supported 50% of breeding bird species found in the original eucalyptus forests (Gepp 1976, Suckling et al. 1976, Driscoll 1977). Only Falkenberg et al. (1983) has investigated bird communities in neotropical pine plantations; they found fewer birds in Caribbean pine plantations than in native forest sites in Jamaica. Resource use by birds in neotropical pine plantations has not been quantitatively examined. Information on bird use of neotropical pine plantations is needed because 33% of all tropical plantations are in the neotropics and the most commonly planted species are pine (Pinus spp.) (Evans 1982). The objectives of my research were to describe avian resource use in a Caribbean pine plantation and analyze niche structure, food resource relationships, and other factors associated with the bird assemblage patterns. This study was conducted under the auspices of the Institute of Tropical Forestry, U.S. Forest Service, Puerto Rico, and the U.S. Man and the Biosphere Program on Tropical Forests. I am indebted to A. E. Lugo for guidance, cooperation, and helpful suggestions. I also profited from discussions with W. J. Arendt, G. P. Bauer, C. E. Bock, B. B. Cintron, C. A. Delannoy, J. C. Figueroa, G. E. Freeman, J. A. Moreno, T. K. Nakamura, T. R. Strong, F. H. Wadsworth, P. L. Weaver, and J. W. Wiley. I gratefully acknowledge the valuable field assistance of A. Arendt, W. J. Arendt, and E. Hernandez-Prieto and the forest structural information provided by A. E. Lugo. Financial support came from a National Research Council (Ford Found.) Postdoctoral Fellowship, Grant-in-Aid from the University of Colorado, and a National Geographic Society Grant.