13 Abstract Current methods for estimating feral pigeon (Columba livia) population size and 14 for monitoring population trends are mainly based on indices, which according to the 15 current literature on wildlife census methods often produce biased results. Distance 16 Sampling techniques have never been used in this context, even though they could 17 theoretically produce absolute abundance e...

Recent reports indicate that populations of the black sea urchin Diadema antillarum are slowly coming back in several localities in the Caribbean after 15 years of absence. In La Parguera, Puerto Rico, urchins were totally absent from reef localities until 1996, when isolated, medium size individuals were observed in shallow reef habitats. To assess the status (distribution, densities and size ...

Although nitrification has been well studied in coniferous forests of Western North America, communities of NH(3)-oxidizing bacteria in these forests have not been characterized. Studies were conducted along meadow-to-forest transects at two sites (Lookout and Carpenter) in the H. J. Andrews Experimental Forest, located in the Cascade Mountains of Oregon. Soil samples taken at 10- or 20-m inter...

The 1983-84 Caribbean-wide mortality of the urchin Diadema antillarum Philippi was followed by a second mortality event in the Florida Keys in 1991. The demise of this once ubiquitous herbivore is one factor contributing to wider Caribbean reef change during the past 25 years. Over an 8-year period from 1999-2007, we examined densities and test sizes of D. antillarum at 786 sites from the north...

Quantifying and understanding the processes driving turbulent mixing around Antarctica are key to closing Southern Ocean's heat budget, an essential component of global climate system. In 2016, a glider deployed in Ryder Bay, West Antarctic Peninsula, collected hydrographic microstructure data, obtaining some first direct measurements kinetic energy dissipation off Antarctica. Elevated O(10−8) ...

Epiphytic vascular plants are common species in humid tropical forests. Epiphytes are influenced by abiotic and biotic variables, but little is known about the relative importance of direct and indirect effects on epiphyte distribution. We surveyed 70 transects (10 m × 50 m) along an elevation gradient (180 m-1521 m) and sampled all vascular epiphytes and trees in a typical tropical forest on H...

It has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crowncover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight and seed production per individual o...

This study describes a step-by-step process used to design an effective benthic video survey component of the Commonwealth of the Northern Mariana Islands long-term monitoring program. Documenting abundance of major benthic groups at relatively large spatial scales, at the appropriate localities, can empower monitoring programs with the capacity to detect changes over time and assess whether ma...

Repeated transects have become the backbone of spatially distributed ice and snow thickness measurements crucial for understanding mass balance. Here we detail at Multidisciplinary drifting Observatory Study Arctic Climate (MOSAiC) 2019–2020, which represent first such collected across an entire season. Compared with similar historical transects, MOSAiC was thin (mean depths approximately 0.1–0...