Time filter

Source Type

San Vito, Costa Rica

Mendenhall C.D.,Stanford University | Sekercioglu C.H.,University of Utah | Brenes F.O.,Las Cruces Biological Station | Ehrlich P.R.,Stanford University | Daily G.C.,Stanford University
Proceedings of the National Academy of Sciences of the United States of America | Year: 2011

Growing demand for food, fuel, and fiber is driving the intensification and expansion of agricultural land through a corresponding displacement of native woodland, savanna, and shrubland. In the wake of this displacement, it is clear that farmland can support biodiversity through preservation of important ecosystem elements at a fine scale. However, how much biodiversity can be sustained and with what tradeoffs for production are open questions. Using a well-studied tropical ecosystem in Costa Rica, we develop an empirically based model for quantifying the "wildlife- friendliness" of farmland for native birds. Some 80% of the 166 mist-netted species depend on fine-scale countryside forest elements (≤60-m-wide clusters of trees, typically of variable length and width) that weave through farmland along hilltops, valleys, rivers, roads, and property borders. Our model predicts with ∼75% accuracy the bird community composition of any part of the landscape. We find conservation value in small (≤20 m wide) clusters of trees and somewhat larger (≤60 m wide) forest remnants to provide substantial support for biodiversity beyond the borders of tropical forest reserves. Within the study area, forest elements on farms nearly double the effective size of the local forest reserve, providing seminatural habitats for bird species typically associated with the forest. Our findings provide a basis for estimating and sustaining biodiversity in farming systems through managing fine-scale ecosystem elements and, more broadly, informing ecosystem service analyses, biodiversity action plans, and regional land use strategies. Source

Zahawi R.A.,Las Cruces Biological Station | Holl K.D.,University of California at Santa Cruz | Cole R.J.,University of California at Santa Cruz | Cole R.J.,University of Colorado at Boulder | Reid J.L.,University of California at Santa Cruz
Journal of Applied Ecology | Year: 2013

Active forest restoration typically involves planting trees over large areas; this practice is costly, however, and establishing homogeneous plantations may favour the recruitment of a particular suite of species and strongly influence the successional trajectory. An alternative approach is to plant nuclei (islands) of trees to simulate the nucleation model of succession and accelerate natural recovery. We evaluated natural tree recruitment over 4 years in a restoration study replicated at eight former pasture sites in the tropical premontane forest zone of southern Costa Rica. At each site, two active restoration strategies were established in 50 × 50 m plots: planting trees throughout, and planting different-sized tree islands (4 × 4, 8 × 8, 12 × 12 m) within the plot. Restoration plots were compared to similar-sized controls undergoing passive restoration. Sites were spread across c. 100 km2 and distributed along a gradient of surrounding forest, allowing us to compare the relative importance of adjacent forest to that of within-site treatment on tree recruitment. Recruitment of animal-dispersed tree species was more than twofold higher in active (μ = 0·45 recruits m-2) as compared to passive restoration; recruitment was equivalent in plantation and island treatments, even though only 20% of the area in island plots was planted originally. The majority of recruits (>90%) represented early successional species (n = 54 species total). Density of animal-dispersed recruits was greater in large (0·80 ± 0·66 m-2) than small (0·28 ± 0·36 m-2) islands and intermediate in medium-sized islands. Seedling recruitment (<1 m tall) was greater in the interior of islands as compared to plantations, whereas sapling recruitment was similar, suggesting that island interiors may develop greater density of woody recruits as succession proceeds. Surrounding forest cover did not influence density or species richness of recruits among sites, although this factor may become more important over time. Synthesis and applications. Applied nucleation is a promising restoration strategy that can accelerate forest recovery to a similar degree as plantation-style restoration but is more economical. Appropriate island size is on the order of c. 100 m2. Practitioners should consider the methodology as an alternative to large-scale plantings. Applied nucleation is a promising restoration strategy that can accelerate forest recovery to a similar degree as plantation-style restoration but is more economical. Appropriate island size is on the order of c. 100 m2. Practitioners should consider the methodology as an alternative to large-scale plantings. © 2012 British Ecological Society. Source

Lindell C.A.,Michigan State University | Cole R.J.,University of California at Santa Cruz | Cole R.J.,University of Hawaii at Manoa | Holl K.D.,University of California at Santa Cruz | Zahawi R.A.,Las Cruces Biological Station
Bird Conservation International | Year: 2012

Tropical land cover change has negatively affected numerous migratory bird populations. Forest restoration can augment migrant wintering habitat. However, almost no information exists about factors that influence migrant use of tropical restoration sites. We sampled migrant birds in young restoration sites in Costa Rica from February 2006 to April 2008 to determine how vegetation height, planting design, season, and landscape forest cover influenced capture rates of four declining species. We also documented total numbers of migratory species and individuals captured in each planting design treatment; each site had a control treatment where seedlings were not planted, an island treatment where seedlings were planted in patches, and a plantation treatment where seedlings were planted to cover the entire area. Sites varied in landscape forest cover within 500 m buffers. Three out of four focal species were captured significantly more often in plantation treatments than island or control treatments. Two of the four species showed seasonal patterns and one species was captured more often in high-vegetation sites. Greater numbers of species and individuals were captured in plantation treatments compared to island and control treatments. The plantation planting design increased migrant use more quickly than the island planting design. When resources are available, we recommend planting plantation-style to rapidly increase the value of restoration sites to a range of species, particularly those that use woody vegetation. When resources are more limited, planting islands may be a cost-effective, although not as ecologically effective, alternative that supports a diversity of migrant species compared to unplanted controls. © Copyright BirdLife International 2011. Source

Cole R.J.,University of California at Santa Cruz | Holl K.D.,University of California at Santa Cruz | Zahawi R.A.,Las Cruces Biological Station
Ecological Applications | Year: 2010

Planting native tree seedlings is the predominant restoration strategy for accelerating forest succession on degraded lands. Planting tree "islands" is less costly and labor intensive than establishing larger plantations and simulates the nucleation process of succession. Assessing the role of island size in attracting seed dispersers, the potential of islands to expand through enhanced seed deposition, and the effect of planting arrangements on seed dispersal by birds and bats informs restoration design. Determining the relative importance of local restoration approach vs. landscape-level factors (amount of surrounding forest cover) helps prioritize methods and locations for restoration. We tested how three restoration approaches affect the arrival of forest seeds at 11 experimental sites spread across a gradient of surrounding forest cover in a 100-km2area of southern Costa Rica. Each site had three 50 X 50 m treatments: (1) control (natural regeneration), (2) island (planting tree seedlings in patches of three sizes: 16 m2, 64 m 2, and 144 m2), and (3) plantation (planting entire area). Four tree species were used in planting (Terminalia amazonia, Vochysia guatemalensis, Erythrina poeppigiana, and Inga edulis). Seed rain was measured for 18 months beginning ~2 years after planting. Plantations received the most zoochorous tree seeds (266.1 ± 64.5 seeds-m-2'yr-1 [mean ± SE]), islands were intermediate (210.4 ± 52.7 seeds.m -2yr-1), and controls were lowest (87.1 ± 13.9 seeds.m-2yr-1). Greater tree seed deposition in the plantations was due to birds (0.51 ± 0.18 seeds'm-2'd -1), not bats (0.07 ± 0.03 seeds-m-2'd -1). Seed rain was primarily smallseeded, early-successional species. Large and medium islands received twice as many zoochorous tree seeds as small islands and areas away from island edges, suggesting there is a minimum island size necessary to increase seed deposition and that seed rain outside of planted areas is strongly reduced. Planting design was more important for seed deposition than amount of forest cover within the surrounding 100- and 500-m radius areas. Establishing plantations and large islands facilitates the arrival of early-successional tree seeds and represents a broadly applicable strategy for increasing seed rain on abandoned agricultural lands. However, more intensive restoration approaches may be necessary for establishment of dispersal-limited species. © 2010 by the Ecological Society of America. Source

Ricardo K.,New York Botanical Garden | Oviedo-Brenes F.,Las Cruces Biological Station
Phytotaxa | Year: 2013

A new species of Miconia, M. povedae is described from a small remnant of primary forest at Las Cruces Biological Station in San Vito, Puntarenas province, Costa Rica. The new species is distinguished by its orangish indument of dendritic and stellate trichomes on most parts of the plant, sessile leaves with a tapering leaf base and strongly plinerved and asymmetric leaf venation, deflexed inflorescences, sessile herkogamous flowers with fused calyces that rupture at anthesis and geniculate staminal filaments. M. povedae is related to a group of for the most part Costa Rican and Panamanian endemics and the distinctive features of M. povedae and these species are discussed. Photographs of live plants, dissections of flowers preserved in ethanol, Scanning Electron Micrographs of leaf trichomes and a distribution map are provided. © 2013 Magnolia Press. Source

Discover hidden collaborations