Exotic Pine Plantations Research Articles

Spatial variability of throughfall and stemflow in an exotic pine plantation of subtropical coastal Australia

AbstractLarge‐scale exotic pine plantations have been developed for timber production in subtropical Australia. Few studies investigate the spatial variability of both throughfall and stemflow in such managed pine plantations despite their acknowledged effects on the heterogeneity of hydrological and biochemical processes of forested ecosystems. To examine the spatial variability of rainfall under a 12‐year‐old pine plantation in a subtropical coastal area of Australia, we observed gross rainfall, throughfall and stemflow over a 1‐year period. Our results show that the spatial variability of gross rainfall within a 50 m × 50 m plot is minimal. Throughfall is significantly different among three tree zones (midway between rows, west and east side of trunks), particularly for rainfall <50 mm, with the highest throughfall on the east side of the tree trunks (sum = 85% of gross rainfall) and the lowest in the midway between tree rows (sum = 68% of gross rainfall). These spatial patterns persist among 84% of recorded rainfall events. Spatial variability and time stability of throughfall are better explained by canopy interception of the inclined rainfall resulting from the prevailing easterly wind direction throughout the experiment. The annual stemflow is different among individual sample trees, which is mainly ascribed to the difference in tree size (e.g. projected canopy area and stem diameter). The outcomes of this study would help future investigators better design appropriate sampling strategies in these pine plantations under similar climate conditions. Copyright © 2014 John Wiley & Sons, Ltd.

Foraging Activity by Bats in a Fragmented Landscape Dominated by Exotic Pine Plantations in Central Chile

We assessed foraging activity of insectivorous bats in a fragmented landscape of central Chile including native temperate forest, forest fragments, commercial pine plantations and local human settlements. Overall bat activity was noticeably greater along adult pine plantation edges, local human settlements and the edge of continuous forest than over interior habitats and unplanted forest plantation clear-cuts. Tadarida brasiliensis foraged mostly above human settlements and edges of adult pine plantations but avoided interior habitats. Lasiurus cinereus was more active along edges of both adult pine plantations and continuous forest than in clearcuts and interior habitats of forest fragments. In contrast, Lasiurus varius, Histiotus montanus and Myotis chiloensis occurred not only along vegetation edges but also within the interior habitats of adult pine plantations. The high activity levels suggest that bats not only pass through exotic pine plantations, but that they are active in these habitats commuting and feeding, thus enhancing their capacity to persist in landscapes modified by humans in which exotic forestry plantations are an important component.

Foliar and litter needle carbon and oxygen isotope compositions relate to tree growth of an exotic pine plantation under different residue management regimes in subtropical Australia

Background and aim Significant differences in tree growth were observed in an exotic pine plantation under different harvest residue management regimes at ages 2–10 years. However, the variations in tree growth between residue management treatments could not be explained by soil and foliar nutrient analyses, except by potassium (K) concentration. Therefore, this study determined the carbon isotope composition (δ13C) and oxygen isotope composition (δ18O) of current and archived foliar samples from the exotic pine plantation to establish relationships with foliar K concentration and tree growth indices as a means to determine changes in stomatal conductance (gs) and photosynthetic rate (Amax) or water use efficiency (WUE), and therefore understand the variations in tree growth across treatments.

Hot water extractable phosphorus pools as indicators of soil P responses to harvest residue management in an exotic pine plantation of subtropical Australia

Purpose This study evaluated the potential of using hot water extractable phosphorus (P) pools as a method to assess the impacts of harvest residue management on the bioavailability of P in an exotic pine plantation of southeast Queensland, Australia.

Can understorey native woodland plant species regenerate under exotic pine plantations using natural succession?

Forestry industry in many European countries has begun to focus on sustainable forest management practices, and consequently, a greater emphasis is now being placed on the restoration and enhancement of native woodlands in places where intensive forestry is nowadays not highly profitable. In this context, we evaluate the natural regeneration of native oak woodland vegetation under cultivated stands of Pinus radiata in the Biscay region, Northern Iberian Peninsula. We compared vegetation composition and diversity on 60 stands representing the three commonly observed habitats: regenerating Quercus robur woodlands, old-growth native Q. robur woodlands, and their adjacent P. radiata plantations at different successional stages. The aim was to assess the potential of natural successional processes to restore the native oak woodland species under pine plantations, determining whether natural regeneration is sufficient or some management interventions are needed. The results reveal significant differences in understorey species composition between pine plantations and oak habitats. However, these understorey compositional differences were reduced during natural successional process (from young to old age plantations), being especially important in the case of tree and fern growth-forms. The successional trends are driven by an increase of tree, fern and native species cover during pine plantations succession, although the richness was always higher in plantations mainly by the presence of a great number of generalist and opportunistic species. Nevertheless, some typical woodland species, such as Ulmus minor and Lamiastrum galeobdolon, did not appear in plantations. Here, the natural successional process produced a slowly convergence in understorey species composition between plantations and oak habitats. However, the old pine plantations and oak habitats still differed considerably in understorey composition, suggesting that using only natural succession a much longer time frame is needed to achieve our ecological restoration objective. Natural succession could be used to achieve the restoration objectives at relatively low costs almost for tree and fern growth-forms, although in the case of ancient woodland species especial actions would be needed. The reorientation of pine plantations towards species compositional states that are more similar to native oak habitats could be faster using adaptive forest management practices (e.g. single tree selection).

The influence of weed control on foliar δ15N, δ13C and tree growth in an 8 year-old exotic pine plantation of subtropical Australia

Background and aims The aim of weed control and fertilization in forest plantations was to increase tree growth by reducing competition for available nutrients and water. However, treatments that influence weed biomass can also have significant impacts on soil carbon (C) and nitrogen (N) cycling which can in turn lead to changes in the dynamics of stable C (δ13C) and N (δ15N) isotope compositions in soils and tree foliage.

Using high resolution digital aerial imagery interpreted in a 3-D digital GIS environment to map predefined plant communities in central-southern New South Wales.

Aerial photo interpretation of high resolution airborne imagery (ADS40) was used in a three-dimensional (3-D) digital Geographic Information System (GIS) environment to map native plant communities defined in the NSW Vegetation Classification and Assessment (NSW VCA) in central-southern New South Wales. NSW VCA plant community types form part of the NSW BioMetric vegetation type dataset underpinning NSW natural resource management (NRM) planning frameworks. This region was previously devoid of detailed vegetation mapping. In addition to developing a novel method for mapping plant communities, the use of ADS40 imagery allowed for capture of multiple attributes in each map polygon including attributes pertaining to dominant species and vegetation condition. Such data informs multi-attribute models used in conservation planning, providing utility beyond that of a singular plant community map. A total of 546,150 hectares of native vegetation in 100 native plant communities was mapped across the study area (Coolamon, Cootamundra, Junee, Lockhart, Narrandera, Tarcutta, Urana, Wagga Wagga and Yanco 1:100,000 mapsheets and Ariah Park, Wallaroobie Range and Yoogali 1:50,000 mapsheets). Exotic pine plantations and native species plantings were also mapped. Remnants of greater than one hectare were captured through on-screen GIS digitising at scales of approximately 1:4,000. The plant community type mapping was independently assessed using random blind validation points as having a user accuracy of 87%. This level of accuracy demonstrates the applicability of the methodology for mapping open forests, woodlands and open woodlands of south-eastern Australia and probably other vegetation elsewhere. Such accurate mapping provides end users with confidence when using vegetation maps in environmental assessment and land use planning.

Optimizing manual sampling schedule for estimating annual soil CO2 efflux in a young exotic pine plantation in subtropical China

Optimizing a manual measurement schedule (both frequency and pattern) for estimating annual soil respiration (RS) is an important but unresolved issue. We hypothesized that (i) an optimal sampling setup can be found to obtain a reliable annual RS, and (ii) if the desired outcome is a multi-year mean annual RS, a lower sampling frequency might be adequate. Here we explored these issues using a three-year chamber-based dataset, with a sampling frequency of twice per week (defined as control), in an exotic slash pine (Pinus elliottii Englem.) plantation in subtropical China. The results showed that RS during 9:00–11:00a.m. represented diurnal mean RS well. In order to obtain an annual RS as reliable as the control (deviation within ±5%), the optimal measurement strategy is a biweekly sampling across a year and not a trade-off sampling pattern (monthly sampling combined with weekly sampling depending on the seasons). Furthermore, despite an obvious inter-annual variability in RS (548.4–757.5gCm−2year−1, CV=16.3%), a monthly sampling was sufficient to obtain an unbiased multi-year mean annual RS (deviation within ±5%). Such findings are useful when easy looking for estimates of annual ecosystem carbon budgets. However, the generality needs to be examined in other ecosystems.

Do exotic pine plantations favour the spread of invasive herbivorous mammals in Patagonia?

AbstractChanges in land use patterns and vegetation can trigger ecological change in occupancy and community composition. Among the potential ecological consequences of land use change is altered susceptibility to occupancy by invasive species. We investigated the responses of three introduced mammals (red deer,Cervus elaphus; wild boar,Sus scrofa; and European hare,Lepus europaeus) to replacement of native vegetation by exotic pine plantations in the Patagonian forest‐steppe ecotone using camera‐trap surveys (8633 trap‐days). We used logistic regression models to relate species presence with habitat variables at stand and landscape scales. Red deer and wild boar used pine plantations significantly more frequently than native vegetation. In contrast, occurrence of European hares did not differ between pine plantations and native vegetation, although hares were recorded more frequently in firebreaks than in plantations or native vegetation. Presence of red deer and wild boar was positively associated with cover of pine plantations at the landscape scale, and negatively associated with mid‐storey cover and diversity at the stand scale. European hares preferred sites with low arboreal and mid‐storey cover. Our results suggest that pine plantations promote increased abundances of invasive species whose original distributions are associated with woodlands (red deer and wild boar), and could act as source or pathways for invasive species to new areas.

Ectomycorrhizal fungi of exotic pine plantations in relation to native host trees in Iran: evidence of host range expansion by local symbionts to distantly related host taxa

Introduction of exotic plants change soil microbial communities which may have detrimental ecological consequences for ecosystems. In this study, we examined the community structure and species richness of ectomycorrhizal (EcM) fungi associated with exotic pine plantations in relation to adjacent native ectomycorrhizal trees in Iran to elucidate the symbiont exchange between distantly related hosts, i.e. Fagales (Fagaceae and Betulaceae) and Pinaceae. The combination of morphological and molecular identification approaches revealed that 84.6 % of species with more than one occurrence (at least once on pines) were shared with native trees and only 5.9 % were found exclusively on pine root tips. The community diversity of ectomycorrhizal fungi in the pine plantations adjacent to native EcM trees was comparable to their adjacent native trees, but the isolated plantations hosted relatively a species-poor community. Specific mycobionts of conifers were dominant in the isolated plantation while rarely found in the plantations adjacent to native EcM trees. These data demonstrate the importance of habitat isolation and dispersal limitation of EcM fungi in their potential of host range expansion. The great number of shared and possibly compatible symbiotic species between exotic Pinaceae and local Fagales (Fagaceae and Betulaceae) may reflect their evolutionary adaptations and/or ancestral compatibility with one another.

Rainfall pulse primarily drives litterfall respiration and its contribution to soil respiration in a young exotic pine plantation in subtropical China

Although litterfall respiration (RL) is a key process of soil carbon dynamics in forests, factors that drive RL and its contribution to soil respiration (RS) have not been sufficiently studied. Using a litter removal method, we researched RL and the ratio of RL:RS in a 20-year-old exotic slash pine ( Pinus elliottii Englem.) plantation in subtropical China. Soil temperature explained 67%, 78%, and 25% of variation in RS, mineral soil respiration (RS-L), and RL, respectively, but had little impact on RL:RS. To study influences besides temperature, measured RS and RS-L were normalized using the Arrhenius equation. Even though this subtropical plantation was characterized by a humid climate with abundant precipitation, a rainfall pulse induced increase in soil moisture primarily drove RL and its contribution to RS but depressed RS-L. The response of RL to rainfall and soil moisture was significantly more sensitive than that of RS-L. Furthermore, the effects of rainfall and soil moisture on RS, RL, and RL:RS were higher during the dry season (July–December) than during the wet season (January–June). In the context of climate change, RL and its contribution to RS are expected to decrease because of the predicted decrease in rainfall amount and frequency in subtropical regions.

Erratum to: Effects of weed control and fertilization on soil carbon and nutrient pools in an exotic pine plantation of subtropical Australia

Erratum to: Effects of weed control and fertilization on soil carbon and nutrient pools in an exotic pine plantation of subtropical Australia

Effects of weed control and fertilization on soil carbon and nutrient pools in an exotic pine plantation of subtropical Australia

Purpose Soil carbon (C) and nutrient pools under different plantation weed control and fertilizer management treatments were assessed in a 7-year-old, F1 hybrid (Pinus elliottii var. elliottii × Pinus caribaea var. hondurensis) plantation in southeast Queensland, Australia. This research aimed to investigate how early establishment silvicultural treatments would affect weed biomass, soil C, nitrogen (N) and other nutrient pools; and soil C (δ13C) and N isotope composition (δ15N) to help explain the key soil processes regulating the soil C and nutrient pools and dynamics.

Exotic Pinus carbaea causes soil quality to deteriorate on former abandoned land compared to an indigenous Podocarpus plantation in the tropical forest area of southern China

Soil properties under an exotic plantation (Pinus caribaea) and an indigenous plantation (Podocarpus imbricatus) were compared with adjacent secondary forests and abandoned land in the tropical forest areas of Jianfengling National Nature Reserve in Hainan province, southern China. The surface soil (0–0.2 m) under Pi. caribaea has higher bulk density, lower soil organic carbon, total N, total K, available N, microbial biomass carbon, and smaller soil microbial communities (as indicated by soil Biolog profiles) than under Po. imbricatus. Both land use types showed negative cumulative soil deterioration index (DI) compared to secondary forests. However, compared to abandoned land (DI = –262), the soil quality of Po. imbricatus showed improvement (DI = –194) while that of Pi. caribaea showed deterioration (DI = –358). These results demonstrated that these exotic pine plantations can significantly and negatively influence soil properties. By contrast, our results showed that adoption of indigenous species in plantations, or natural regeneration, can improve soil quality.

The effects of land use on environmental features and functional organization of macroinvertebrate communities in Patagonian low order streams

Benthic invertebrates, water quality variables, chlorophyll a and particulate organic matter (POM) were studied in 18 sites of mountain streams in Patagonia (Argentina) subjected to six different land uses: native forest, pine plantation, pasture, harvest forest, urban and reference urban. Three streams of each land use were studied in March 2006. Macroinvertebrates were sampled in three riffles and three pools ( n = 108) and biomass of detrital fractions of POM were quantified. Overall benthic POM biomass was higher at native and harvest forest than pastures, whereas fine fraction (FPOM) was higher in harvest forest than in pastures. Regarding to autotrophic subsidies bryophytes were the only that changed consistently among uses. These differences in energy resources were correlated with changes in community attributes. Shredder richness was clearly higher at native and harvest forest than exotic pine plantations, collector gatherers density was consistently high at harvest sites, and total density was significantly higher at urban and harvest forest. Multidimensional scaling ordination based on macroinvertebrate density data showed a clear separation of forested (either native or exotic species) from riparian modified areas (pasture, urban and harvest sites). Environmental variables having explanation power on macroinvertebrate assemblages were mostly related with: detritus availability (wood and leaves biomass) and impairment (total phosphorous and % sand). These results confirm that macroinvertebrate assemblage structure in Patagonian low order streams can be altered by land use practices. Among guild structure measures, those indicators based on benthic community functional attributes, shredders richness and collectors density, resulted good candidates to assess land use impacts. On account of riparian corridor management may be critical to the distribution of benthic taxa, the maintenance of good conditions of vegetation adjacent to rivers will enhance water quality and the environment for highly endemic headwater communities of Patagonian streams.

An improved method for purifying genomic DNA from forest leaf litters and soil suitable for PCR

Background, aim and scope An improving knowledge of bacterial community within natural environments including forest soils and leaf litters requires extraction of nucleic acids directly from environmental samples since molecular approaches provide less biased access to a larger portion of uncultivable microorganisms. However, when DNA was extracted successfully from these samples, it might still have been difficult to apply it as a template for polymerase chain reaction (PCR) amplifications due to the effect of PCR inhibitors. Various compounds from plant tissues including polysaccharides, phenolic compounds and especially humic acids can inhibit PCR amplification. Some of these inhibitors could inhibit PCR amplification by chelating the Mg2+ (cofactor for Taq polymerase), or by binding to target DNA, and PCR amplification would consequently be interfered with. Therefore, eliminating the effects of these PCR inhibitors is one of the most important steps for PCR-based molecular techniques. Four different methods were assessed in this study to purify the genomic DNA extracted from F, L layer leaf litters and forest soil in an exotic pine plantation of southeast Queensland, Australia.

Culture-dependent and culture-independent microbial investigation of pine litters and soil in subtropical Australia

Background, aim, and scope Forest plantations, widely grown for wood production, involve the selective promotion of single-tree species or replacement of natural species by exotic tree species. Slash pine (Pinus elliottii) has been chosen for reforestation of infertile sandy soils in southeast Queensland, Australia. These exotic pine plantations minimize soil and water losses and are important scientific study sites. The soil environment of these plantations, though devoid of sufficient nutrients, organic carbon and other factors, harbors innumerable bacteria that may play a crucial role in maintaining soil quality and ecosystem functions. These soil microorganisms also have the potential for use as sensitive biological indicators to reflect environmental changes. It is therefore essential to understand the interrelationships among bacterial communities and their environment by assessing their structural and functional diversity and their responses to disturbances. The main aim of our investigation was to determine the diversity of bacterial communities in forest litters and soil during the forest leaf litter decomposition using culturedependent and culture-independent techniques. Materials and methods A 25-cm (diameter)×40-cm core sample was collected and fractionated into three subsamples designated E1 (L leaf litter layer), E2 (F leaf litter layer), and E5 (0–10 cm soil layer). Both culture-dependent and culture-independent methods were applied in this study. In the culture-independent study, a strategy of wholecommunity DNA extraction, polymerase chain reaction (PCR) amplification followed by cloning and 16S rDNA sequence analysis was used; for culture-dependent study, the strategy included sample plating and bacteria isolating, DNA extraction, PCR amplification, and 16S rDNA sequence analysis. The diversity similarities between two bacterial communities and two methods are quantified using Jensen–Shannon divergence. Results From culture-dependent study, 336 colonies in total were isolated and grouped from the three subsamples, and the 16S rRNA sequence analysis from a representative isolate from each morphogroup (21 isolates) indicated that they belonged to the phyla Actinobacteria, Firmicutes, and Proteobacteria. Culture-independent assessment based on 16S rRNA gene library comprising 194 clones revealed that members of the phylum Actinobacteria were absent in the culture-independent studies. Clones in libraries from E1 consisted exclusively of members of the Firmicutes. The majority of clones from E2 were related to Firmicutes (79%) and Proteobacteria (21%). Clones derived from E5 were mostly affiliated with Acidobacterium (42%), followed by unclassified bacteria (27%), Verrucomicrobiales (12%), Proteobacteria (11%), and Planctomycetes (8%). Discussion This study showed that bacterial culturabilities in different fractions of leaf litters were similar, and both of them were higher than the bacterial culturability in the soil. Unculturable bacterial diversity in the soil, however, was much higher than the leaf litter bacterial diversity. The bacterial diversity on the top layer of leaf litters was slightly

Flower and fruit production and insect pollination of the endangered Chilean tree, Gomortega keule in native forest, exotic pine plantation and agricultural environments

El presente estudio fue realizado con el objetivo de establecer si los patrones de produccion de flores y frutos de Gomortega keule (Gomortegaceae), un arbol chileno en peligro de extincion, son diferentes entre areas de plantaciones de pinos exoticos, terrenos agricolas y areas de bosque nativo. Tambien fue llevado a cabo un estudio piloto para identificar los principales polinizadores de G. keule. A pesar de que en tierras agricolas y en areas de bosque nativo florecio una proporcion similar de arboles de G. keule, en zonas agricolas fructifico una mayor proporcion en comparacion con los arboles de areas de bosque nativo. La floracion y fructificacion de G. keule fue extremadamente rara en las areas de plantaciones de pinos exoticos. Nuestros datos indican que las flores de G. keule son visitadas predominantemente por sirfidos durante marzo y abril, y que dichos sirfidos transportan una mayor proporcion de polen de G. keule que cualquier otro insecto recolectado. El bosque nativo y los sistemas agricolas no intensivos parecen proporcionar a los sirfidos un habitat en el cual alimentarse y donde G. keule es capaz de fructificar, lo cual no sucede en las plantaciones de pinos exoticos. Esto sugiere que un paisaje compuesto por un mosaico de diferentes tipos de uso del suelo no es necesariamente hostil para la reproduccion continua de G. keule, pero que la combinacion y tipos de uso del suelo e intensidad de su manejo deben ser consideradas cuidadosamente.

Impacts of the Replacement of Native Woodland with Exotic Pine Plantations on Leaf-Litter Invertebrate Assemblages: A Test of a Novel Framework

We present an empirical comparison of invertebrate community structure between areas of undisturbed native eucalypt woodland and areas that have been cleared and replaced with plantations of exotic radiata pine (Pinus radiata). Implementation of a novel conceptual framework revealed that both insect (in autumn) and arachnid (in winter) assemblages demonstrated inhibition in response to the pine plantations. Species richness declines occurred in several taxonomic Orders (e.g., Hymenoptera, Blattodea, Acari) without compensated increases in other Orders in plantations. This was, however, a seasonal response, with shifts between inhibition and equivalency observed in both insects and arachnids across autumn and winter sampling periods. Equivalency responses were characterized by relatively similar levels of species richness in plantation and native habitats for several Orders (e.g., Coleoptera, Collembola, Psocoptera, Araneae). We propose testable hypotheses for the observed seasonal shifts between inhibition and equivalency that focus on diminished resource availability and the damp, moist conditions found in the plantations. Given the compelling evidence for seasonal shifts between categories, we recommend that seasonal patterns should be considered a critical component of further assemblage-level investigations of this novel framework for invasion ecology.

Long-term impacts of harvest residue management on nutrition, growth and productivity of an exotic pine plantation of sub-tropical Australia

Residue retention is an important issue in evaluating the sustainability of production forestry. However, its long-term impacts have not been studied extensively, especially in sub-tropical environments. This study investigated the long-term impact of harvest residue retention on tree nutrition, growth and productivity of a F1 hybrid ( Pinus elliottii var. elliottii × Pinus caribaea var. hondurensis) exotic pine plantation in sub-tropical Australia, under three harvest residue management regimes: (1) residue removal, RR 0; (2) single residue retention, RR 1; and (3) double residue retention, RR 2. The experiment, established in 1996, is a randomised complete block design with 4 replicates. Tree growth measurements in this study were carried out at ages 2, 4, 6, 8 and 10 years, while foliar nutrient analyses were carried out at ages 2, 4, 6 and 10 years. Litter production and litter nitrogen (N) and phosphorus (P) measurements were carried out quarterly over a 15-month period between ages 9 and 10 years. Results showed that total tree growth was still greater in residue-retained treatments compared to the RR 0 treatment. However, mean annual increments of diameter at breast height (MAID) and basal area (MAIB) declined significantly after age 4 years to about 68–78% at age 10 years. Declining foliar N and P concentrations accounted for 62% ( p < 0.05) of the variation of growth rates after age 4 years, and foliar N and P concentrations were either marginal or below critical concentrations. In addition, litter production, and litter N and P contents were not significantly different among the treatments. This study suggests that the impact of residue retention on tree nutrition and growth rates might be limited over a longer period, and that the integration of alternative forest management practices is necessary to sustain the benefits of harvest residues until the end of the rotation.