Non-fragmented Forests Research Articles

Dispersion of the epigeic fauna groups in the agricultural landscape

Abstract Changes in the structure of epigeic animal groups indicate ecological stability, which are influenced by urbanization, agriculture, and forestry. The aim of the paper was to assess the impact of agrarian land in the vicinity of urban and suburban landscape and non-fragmented forest in the vicinity of rural landscape on the occurrence of epigeic groups. We recorded the pitfall traps - 19, 676 individuals belonging to 20 taxonomic groups at 9 localities representing 7 types of habitat. Our results indicate a year-on-year increase in the number of individuals of epigeic groups in the city, with surrounding agrarian land. We found a correlation between eudominant epigeic groups of Aranea and Hymenoptera and rural landscape with the non-fragmented surrounding. Coleoptera has shown a link between the conditions of urban and suburban landscape with the surrounding developed agriculture. We confirmed a statistically significant effect for luminosity (p = 0.002), humidity (p = 0.025) and pH (p = 0.017).

Decline in Aboveground Biomass Due to Fragmentation in Subtropical Forests of China

Fragmentation has long been considered the primary cause for ecosystem degradation and biodiversity loss worldwide. Forest fragmentation affects ecosystem functioning and biodiversity in multiple ways. Here, we ask how forest fragmentation influences aboveground biomass storage (AGB) in sub-tropical forests in China. We established 207 20 m × 20 m plots within 69 forest fragments of varying size. Forest fragmentation process simulation was carried out via repeated quadrat sampling using different sized quadrats in two non-fragmented stands. AGB was estimated and compared across forest fragments and quadrats with different sizes within two non-fragmented stands. Our results indicate that AGB is significantly lower in forest fragments than in quadrats within two non-fragmented forests. In addition, species richness and abundance were lower in fragmented stands, respectively. In fragmented forests, the average diameter at breast height (DBH) increased with decreasing patch size, while declined for non-fragmented plots. Species richness, abundance, and mean DBH have strongly positive effects on AGB. This was the case both in forest fragments and quadrats within two non-fragmented forests. Forest fragmentation leads to lower richness, lower abundance, and higher mean DBH in forest fragments than in the two non-fragmented forests. Our results suggest that forest fragmentation increases edge habitats, which drastically decreases forests aboveground biomass storage. These results show that land degradation not only reduces the area of forests, but also reduces the aboveground biomass carbon density of forests.

The changing trend in songbirds’ abundance, variety and physical condition in Connecticut’s forestry habitat

Abstract Songbirds are facing rapid population declines in Connecticut due to habitat loss. Man-made habitats such as powerline corridors are one of the few remaining ideal habitats for songbirds in the state. This study aims to determine if the abundance and variety of song-birds in four selected forests (i.e. Naugatuck State Forest, Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety) in Connecticut show patterns of decline from 2005 to 2014. This study also compares the physical condition of songbirds captured along a powerline corridor in the Naugatuck State Forest with those captured in the rest three non-fragmented forests in Northwestern Connecticut using Mann-Whitney U tests. Weight and wingspan are used as indicators of bird physical condition. The results demonstrate that the three non-fragmented forests experienced a steady decline in the variety of songbirds between 2005 and 2014. In addition, songbirds’ abundance decreased steadily during the same period, except that of the ovenbird (Seiurus aurocapilla) and wood thrush (Hylocichla mustelina) in Miles Wildlife Sanctuary. The results from the Mann-Whitney U test have shown that after sex- and age-controlled features, the physical conditions of the three selective songbirds – veery (Catharus fuscescens), ovenbird, and wood thrush – tend to be better in the Naugatuck State Forest than in the three non-fragmented forests – Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety. Given are recommendations on how to protect the shrubland habitat along powerline corridors and how to create the shrubland habitat in non-fragmented forests.

Defaunation and biomass collapse of mammals in the largest Atlantic forest remnant

Large continuous rainforests are the main hope for sustaining the population of large-bodied vertebrates that cannot cope with fragmentation or unsustainable hunting. The Brazilian Atlantic forest is considered a biodiversity hotspot and although highly fragmented, it still contains large forest patches that may be important for the conservation of mammals that require large areas. Here, we estimated species richness, density and biomass of medium- and large-sized mammals along the largest remnant of the Atlantic rainforest, Brazil (the Serra do Mar bioregion), an estimated area of 8000 km2. We recorded 44 species based on 4090 km of diurnal line transects and camera traps, animal tracks and interviews in 11 continental regions and two large land-bridge islands. We found high levels of similarity in mammalian composition between pairs of sites in the continental forest sites (0.84–1), but much lower similarity between pairs from the continental forest sites and the two large land-bridge islands (0.29–0.74) indicating potential local extinctions or poor dispersal of continental mammals to these islands. In addition, we found that the density and biomass varied 16- and 70-fold among sites, respectively. Mammalian biomass declined by up to 98% in intensively hunted sites and was 53-fold lower than in other Neotropical non-fragmented forests. Although this large forest remnant is able to maintain a high diversity of medium- and large-bodied mammal species, their low density and biomass may affect the long-term persistence of these populations and the ecosystem services they provide.

Territoriality of Copsychus malabaricus in Western Part of the Mihintale Sanctuary, Sri Lanka

The White-rumped Shama (Copsychus malabaricus) (WRS) is a small passerine bird whichhas a melodious song and solitary behaviour that holds a territory all year round. Research onterritorial behaviour of WRS is scare in Sri Lanka. Present study was carried out from May toAugust in 2013 at western border of the Mihintale sanctuary to investigate the territorialbehaviour of WRS. The behavioural studies were done by using the focal sampling method.A dummy of WRS and play back calls were used to check the aggressive behaviour andterritory variations of the bird. Territorial mapping was done using standard methoddescribed by Bibby et al (1993). Breeding success was measured by number of eggs in eachnest and number of chicks emerged from relevant nest. The frequently used trees for nestbuilding were measured by frequency of visiting time of each tree species. Individuals ofWRS were marked with coloured plastic rings prior to the study. Three territories wereselected from fragmented and non-fragmented forest patches to continue the study. Duringthe non-breeding period size of territory is approximately 26,255.6 m2 while during thebreeding period their territory size varies to 20,777.51 m2 – 33,296.03 m2. The size of theterritory depends on the degree of habitat disturbances. The results revealed that thesuccessful breeding was observed in non-fragmented forest patch than the fragmented forestpatch. Calling (43%) and moving (43%) behaviours were high in male and femalerespectively during the non-breeding period. During the breeding period lifting tail wasprominent in male while preening was prominent in female. Every 13 seconds male producedcalls both breeding and non-breeding periods. During the site selecting period both have highpercentage (male -50% and female -54%) of moving while during the nest guarding period,male showed high tail lifting and calling behaviours. The perching height varies with the siteselecting behaviour. Average perching height of male and female ranging from 2.348 m(±1.2) to 3.41 m (±1.87) and 1.25 m (±0.75) to 2.63 m (±0.89) respectively. Perching heightis significantly different (p< 0.05) during the breeding and non-breeding periods. Drypetessepiara and Pterospermum canescens were frequently used trees for the nest building. Theyselected 49-150cm height from the ground level for nest construction and the nest length is9.85 cm, 7.7 cm width and thickness is 2.7 cm. Parts of Ficus aerial roots, dried leaves, sticksand grasses used as for nest building materials. Average clutch size was 2±1 and length ofegg was 2.14 cm-2.35 cm and width was 1.18-1.6 cm (ρ=-0.990).

Structure, ecology and plant richness patterns in fragmented beech forests

Background: Landscape fragmentation constitutes one of the most severe causes of global biodiversity loss. Aims: We studied Fagus sylvatica forests with different levels of fragmentation to address the following question: do fragmented and non-fragmented forests present a similar floristic composition and richness, structural parameters and ecological features? Methods: Vascular plant species were randomly sampled based on a beech forest map classified into three fragmentation levels. We compared overall native and diagnostic species richness patterns of the different fragmentation levels using rarefaction curves and the ratio between diagnostic and all species curves. We also contrasted different fragmentation levels of beech forests, focusing on floristic information, structural parameters, standard ecological features and the distribution of edge and clearing species. Results: Rarefaction analysis showed two opposite trends: the diversity of diagnostic species decreased in fragmented forests as the overall diversity increased. In highly fragmented forests, we found significantly higher values for therophyte and phanerophyte frequencies, light Ellenberg indicator values and edge and clearing species diversity. Conclusions: The integration of floristic analysis, particularly of certain diagnostic groups, with structural and ecological studies is more sensitive and significant than species richness alone, and could offer useful information for forest conservation and management.

Home Range and Ranging Behaviour of Bornean Elephant (Elephas maximus borneensis) Females

BackgroundHome range is defined as the extent and location of the area covered annually by a wild animal in its natural habitat. Studies of African and Indian elephants in landscapes of largely open habitats have indicated that the sizes of the home range are determined not only by the food supplies and seasonal changes, but also by numerous other factors including availability of water sources, habitat loss and the existence of man-made barriers. The home range size for the Bornean elephant had never been investigated before.Methodology/Principal FindingsThe first satellite tracking program to investigate the movement of wild Bornean elephants in Sabah was initiated in 2005. Five adult female elephants were immobilized and neck collars were fitted with tracking devices. The sizes of their home range and movement patterns were determined using location data gathered from a satellite tracking system and analyzed by using the Minimum Convex Polygon and Harmonic Mean methods. Home range size was estimated to be 250 to 400 km2 in a non-fragmented forest and 600 km2 in a fragmented forest. The ranging behavior was influenced by the size of the natural forest habitat and the availability of permanent water sources. The movement pattern was influenced by human disturbance and the need to move from one feeding site to another.Conclusions/SignificanceHome range and movement rate were influenced by the degree of habitat fragmentation. Once habitat was cleared or converted, the availability of food plants and water sources were reduced, forcing the elephants to travel to adjacent forest areas. Therefore movement rate in fragmented forest was higher than in the non-fragmented forest. Finally, in fragmented habitat human and elephant conflict occurrences were likely to be higher, due to increased movement bringing elephants into contact more often with humans.

Small effect of fragmentation on the genetic diversity of Dalbergia monticola, an endangered tree species of the eastern forest of Madagascar, detected by chloroplast and nuclear microsatellites.

The oriental forest ecosystem in Madagascar has been seriously impacted by fragmentation. The pattern of genetic diversity was analysed on a tree species, Dalbergia monticola, which plays an important economic role in Madagascar and is one of the many endangered tree species in the eastern forest. Leaves from 546 individuals belonging to 18 small populations affected by different levels of fragmentation were genotyped using eight nuclear (nuc) and three chloroplast (cp) microsatellite markers. For nuclear microsatellites, allelic richness (R) and heterozygosity (H(e,nuc)) differed between types of forest: R = 7.36 and R = 9.55, H(e,nuc) = 0.64 and H(e,nuc) = 0.80 in fragmented and non-fragmented forest, respectively, but the differences were not significant. Only the mean number of alleles (N(a,nuc)) and the fixation index F(IS) differed significantly: N(a,nuc) = 9.41 and N(a,nuc) = 13.18, F(IS) = 0.06 and F(IS) = 0.15 in fragmented and non-fragmented forests, respectively. For chloroplast microsatellites, estimated genetic diversity was higher in non-fragmented forest, but the difference was not significant. No recent bottleneck effect was detected for either population. Overall differentiation was low for nuclear microsatellites (F(ST,nuc) = 0.08) and moderate for chloroplast microsatellites (F(ST,cp) = 0.49). A clear relationship was observed between genetic and geographic distance (r = 0.42 P < 0.01 and r = 0.42 P = 0.03 for nuclear and chloroplast microsatellites, respectively), suggesting a pattern of isolation by distance. Analysis of population structure using the neighbor-joining method or Bayesian models separated southern populations from central and northern populations with nuclear microsatellites, and grouped the population according to regions with chloroplast microsatellites, but did not separate the fragmented populations. Residual diversity and genetic structure of populations of D. monticola in Madagascar suggest a limited impact of fragmentation on molecular genetic parameters.

Status and Trends of Birds in an Extensive Western Massachusetts Forest

Abstract We report forest bird population trends from 1987–2005 at a 280.7-ha site in Chester, MA. Our study site consisted primarily of mid-successional (70–90 yr old) forest in a landscape of similar, non-fragmented forest. Using point counts at 100 stations, we detected 94 species in early June over all years. Mean numbers of species and detections/yr were 57 and 1104, respectively. Species richness and total detections were stable (P ≤ 0.05). We analyzed trends for the 36 most frequently detected species. Four species exhibited significant increasing trends and 10 significant declining trends; 22 species were stable or exhibited no significant trend (P ≤ 0.05). Whether a species was a resident, short-distance, migrant, or Neotropical migrant did not appear to be a determinative factor for trends. Trends were more readily explained by (I) areal and structural expansion of mature forest conditions and (II) forestry treatments that affected 70 ha (25%) of the study site. We report few changes in species ...

Habitat fragmentation disrupts a plant-disperser mutualism in the temperate forest of South America

The disruption of dispersal mutualisms may have profound consequences for seedling recruitment, plant demography, and population persistence, with potential cascading effects throughout the rest of the community. In the temperate forest of South America, the seeds of the mistletoe Tristerix corymbosus, a proposed key species, are dispersed solely by the endemic marsupial Dromiciops gliroides. In three sites that included two contrasting habitats, one fragmented and the other not, we assessed effects of forest fragmentation on marsupial abundance, fruit removal, seed dispersal and seedling recruitment rates. We also compared the age structure of mistletoe populations between fragmented and non-fragmented forest habitats. Fragmentation affected negatively marsupial abundance, fruit removal, seed dispersal, and seedling recruitment. The local extinction of D. gliroides was associated with the complete disruption of mistletoe seed dispersal. Mistletoe populations in fragmented forests exhibited a deficiency in juveniles because of a lack of recruitment. Thus, effects of forest fragmentation on this dispersal mutualism have clear demographic consequences, which may compromise the survival of mistletoe populations.

Are lianas increasing in importance in temperate floodplain forests in the southeastern United States?

Floodplain forests of the southeastern United States are species rich, often with a dense and diverse liana community. Long-term trends in the density and distribution of lianas may indicate shifts in the composition of plant functional types in these forests. Liana communities in non-fragmented forests in Panama and across the Neotropics have increased in size and density over the last two decades of the 20th century. Are similar changes occurring in temperate forests? Evidence from long-term studies of liana communities in two floodplain forests in South Carolina support the findings from tropical forests. In second-growth forests of the Savannah River system, data from five 1-ha plots established in 1979 and monitored for 22 years indicate a steady increase in liana size and density. Likewise, in old-growth floodplain forests of the Congaree National Park, liana density has increased over 12 years in six 1-ha plots after Hurricane Hugo disturbed the forests in 1989. The increase in liana density and size in these floodplain forests of the southeastern United States is of sufficient magnitude to suggest that lianas are likely influencing stand dynamics in these forests. Consequently, we argue that lianas should be included in models of temperate bottomland forest development of the southeastern United States.

RAPID RECOVERY OF DUNG BEETLE COMMUNITIES FOLLOWING HABITAT FRAGMENTATION IN CENTRAL AMAZONIA

Few studies have directly assessed how rapidly functionally important insect communities recover following rain forest loss and fragmentation. In 1986, B. Klein com- pared the dung and carrion beetle assemblages of clearcuts, fragmented, and non-fragmented forests in central Amazonia, reporting drastic short-term changes in community composi- tion. Fifteen years later, we resampled the same sites using identical techniques and found that, with the regrowth of secondary vegetation between forest fragments, the initial dif- ferences had largely disappeared. As the secondary vegetation itself supports dung beetle assemblages similar to those of continuous forest, we conclude that, from the perspective of the dung beetles, the experimentally fragmented area had returned to a continuous state within approximately one decade. These results offer some good news for the conservation of tropical ecosystems, since they suggest that conditions favorable for functionally im- portant arthropods may be quickly restored by secondary regrowth. They also suggest that the preservation of forest fragments and secondary vegetation may provide an important complement to the conservation of intact mature forest.

Simulating the Long-term Response of Tropical Wet Forests to Fragmentation

In the coming decades, a large fraction of the world’s tropical forests will be fragmented into remnants surrounded by secondary vegetation, landuse areas, or roads. It is important to develop integrative tools to monitor the evolution of these fragmented ecosystems. We used the individualoriented and process-based forest growth simulator FORMIND2.0 to investigate the spatial and temporal effects on standing biomass and functional diversity of various intensities and patterns of fragmentation within a forest landscape. The simulator was calibrated for an old-growth wet forest in French Guiana, South America. We found that the standing biomass of forest remnants was reduced significantly compared to a similar area of nonfragmented forest. When fewer but larger remnants were created rather than many small ones, the total loss in biomass and the increase in the abundance of earlysuccessional species were significantly reduced, confirming that edge effects dominate the functioning of forest remnants. We also performed simulations of secondary succession after the landscape had been abandoned. The simulated recovery time in those secondary forests depends on both the size of cleared area and the spatial pattern of the remnant forests.

Current patterns, habitat discontinuities and population genetic structure: the case of the kelp Laminaria digitata in the English Channel

Laminaria digitata is the dominant species of the dense, continuous kelp stands in the English Channel and on the Atlantic coasts of France, where it is harvested for its high quality algi- nates. However, in spite of its ecological and economic importance, our knowledge of the level and organisation of genetic diversity in this species is scant. Here, using comprehensive hierarchical sampling and 7 microsatellite loci, we explored the roles of dispersal strategies, current regimes and habitat discontinuities in shaping genetic structure of L. digitata populations. Our results show that continuous, non-fragmented forests of L. digitata were genetically differentiated at distances greater than 10 km, despite the absence of clear population boundaries. Furthermore, a pattern of isolation- by-distance indicated that gene flow occurred preferentially among adjacent populations following a stepping-stone model. In addition, we analysed the direction of migration using assignment tests and found that currents appeared to play a minor role in orienting gene flow, except in the Gulf of Saint Malo gyre. In contrast, habitat discontinuities were found to accentuate genetic differentiation and resulted in reduced genetic variation of isolated stands. In the context of a potential over-exploitation of kelp stands in Brittany, this study suggests that the existence of neighbouring populations can be vital to maintaining high levels of gene flow and thus, genetic diversity in this species.

Density-Related Changes in Winter Distribution of Snowshoe Hares in Northcentral Minnesota

Patterns of cover-type use in winter by snowshoe hares (Lepus americanus) were determined from presence of pellets on plots searched during 1969-84 when hare numbers increased substantially and subsequently declined. During population lows pellets were present more often in vegetation providing low, dense cover; i.e., Balsam Fir (Abies balsamea)-White Spruce (Picea glauca) (BS) and Cedar (eastern arborvitae, Thuja occidentalis) (CD) types. As hare numbers increased the proportion of plots with pellets increased for all cover types, but fewer were found in types with less cover; i.e., Red Pine (Pinus resinosa)White Pine (P. strobus) (PP) and nonforested (NF). J. WILDL. MANAGE. 50(2):261-264 Snowshoe hare populations in nonfragmented boreal forest cycle markedly with a periodicity of about 10 years (Keith 1963, Keith and Windberg 1978, Wolff 1980). Changes in hare distribution within different cover types occur during these fluctuations (Keith 1966, Wolff 1980), but no long-term record of them has been presented. This note describes such changes as indicated by the relative abundance of hare fecal pellets (Adams 1959, Wolff 1980, Orr and Dodds 1982, Pietz and Tester 1983, Litvaitis et al. 1985) during 1969-84 when the hare population in northern Minnesota increased substantially and subsequently declined. We gratefully acknowledge the assistance of numerous field personnel of the Sect. Wildl., Minn. Dep. Nat. Resour. (MDNR), particularly J. J. Mooty, J. A. Markl, and B. A. Toms. This study was funded and supported by the For. Wildl. Populations and Res. Group (MDNR) and the Off. Endangered Species, U.S. Fish and Wildl. Serv. D. W. Kuehn, L. B. Keith, and R. E. Lake reviewed the manuscript and provided helpful suggestions for improvement. STUDY AREA AND METHODS Hare population levels and cover-type use were studied in the 9-township (839-km2) Bearville Study Area in northeastern Itasca County, Minnesota. Topography in the area is gently to strongly rolling. The mean January temperature at Grand Rapids, about 50 km southwest of the study area, is -15 C, and the July mean is 20 C (Natl. Oceanic and Atmos. Adm. 1983). During winters 1968-69 through 1983-84, January-March snow depth averaged 37 cm (range = 13-71 cm). Snow cover usually is present from early December through early-late