The Ecology of Tropical Epiphytes and Their Relationship to Neotropical Birds- Final
Tropical Epiphytes include a wide variety of species of algae, fungi and plants. forests (like mosses clinging to the base and sides of trees). mainly in order to cater for different sectors of the market, or as an Thus, most of the current epiphyte flora of apple trees in the UK has [W]) are shown in relation to the East Anglian towns Wisbech and King's Lynn .. Recruitment of facultative species probably comes from the spore rain, from the soil. Tree age relationships with epiphytic lichen diversity and lichen life history traits on .. The ecology and distribution of lichens in tropical deciduous and evergreen . () Non-market forest ecosystem services and decision support in Nordic.
For centuries, rainforests have been utilized by many people for many purposes, from the unique properties of individual plants to clearing for land cover use such as agriculture. Because of this historical harvesting and overall deforestation many species are presumed to have been lost to extinction. How many species is the question as we are unable to keep the pace of identification and classification up with the pace of rainforest destruction.
There are remnants of tropical rainforests in areas of historical human impact and climate change that may serve as examples of what occurred naturally in the past Hauenschild and Smith, Becoming less and less peripheral to this discussion are the widespread effects of pollution and rapid global climate change Hietz, While the earth has experienced climate change in its geologic past, the current increased rate of warming can be placed squarely on the shoulders of humans and our associated activities anthropogenic effects.
Another aspect to the distribution of tropical epiphytes is the stratification effect.
Plant-plant relationships - misjon.info
This discussion is addressed below. Bryophytes and lichen form the base of the crown humus supporting a unique community of invertebrates while vascular epiphytes occupying the crown humus will produce fruits and flowers Sillett, Water availability is considered by some to be one of the more important abiotic stresses to epiphytic habitat Zotz and Hietz, One group of vascular epiphytes having a significant adaptation that alleviates this stress, to some degree, is referred to as tank bromeliads.
The tanks are formed by leaves that overlap at the base. The larger individuals of this grouping can hold water for over a week without an external water supply, while some of the smaller species the supply lasts only about a day. On the flip side of the water availability issue is the consequence of too much moisture.
Bromeliads contain trichome shields or structures on the epidermis of the leaves that serve to allow direct moisture and nutrient absorption. When trichomes are continuously covered with moisture, gas exchange may be significantly reduced.
Zotz and Hietz suggest that this may be a reason that these species are lower in abundance within the Cloud Forest. There are several ways in which various epiphytes may obtain nutrients. As mentioned above, aerial fallout or blowing dust, rain and mist can provide nutrients. In addition, the invertebrate community will play a role.
One study documents the role of debris left by ants as an important source of nitrogen for an epiphyte Zotz and Hietz, The nature and interactions of epiphytes are so intriguing that I could continue this discussion for the remainder of the paper. However, I must move forward and get to the heart of the topic! Many of the species that have been studied in North America are neotropical migrants, or those that will winter in the tropics and migrate northward to breeding grounds during the warmer summer season.
Generalists and Specialists In ecology, species are often described by their adaptability to change and ability to be opportunistic.
Those species that are capable of utilizing a wide variety of resources are called generalists. This species will be found deep within a forested environment as well as, quite abundantly, around homes, parks and lawns. An example of a recently re-discovered specialist is the Ivory-billed Woodpecker Campephilus principalis. This species requires a specific habitat type and is unable to adapt to the thinning or clearing of the forests it is adapted to.
This points to the fact that there are degrees of specialization as will be discussed below. Bird Dependence on Epiphytes The use of epiphytes by birds has been observed by a number of researchers. The importance of epiphytes to specialists however, is more difficult to assess and study.
At least species of neotropical birds have been documented as utilizing the resources of epiphytes. Such use includes nest material and nesting sites, water resources and food, including fruit, nectar and invertebrates Nadkarni and Matelson, Nadkarni and Matelson observed bird use of epiphyte resources in the Monteverde, lower montane forest and pastures of Costa Rica.
They found in their study area those families that most frequently used epiphyte resources were hummingbirds Trochilidaetanagers Thraupidae and flycatchers Tyrannidea. In other words, epiphytes provide resources at different times of the year than host plants. Foraging, Cover, and Nest Sites One group of birds in the Tanager family that I only found generally described in our text book is the Euphonias genus Euphonia.
This genus is mentioned as important to mistletoe seed dispersal but also they commonly nest in bromeliads Kricher, The Euphonias are also cited as utilizing other epiphytes for nests including mosses and ferns. The Euphonias appear to prefer this resource as cover for their nests since they are covered by a roof with a side entrance hidden within the dense cover Stiles and Sutch, Insectivorous behavior has also been studied to determine the dependence of birds on epiphyte resources, specifically, the epiphyte mat that harbors an invertebrate community Sillett, The degree of specialization is often important in determining dependence on a resource.
Sillett separated the foraging behaviors of eight species of insectivorous birds into three categories, substrate-restricted, near-surface and prey-specific foraging.
Biodiversity in agricultural landscapes: The effect of apple cultivar on epiphyte diversity
Four of the species observed by Sillett fit the definition of epiphyte specialists. The first three of these are in the family of ovenbirds Furnariidae. Pollinators are largely insects, however a few species of birds and bats are also co-adapted as primary pollinators.
While specific information about the dependence of epiphytic angiosperms on bird pollinators has eluded me, certain species of birds that occupy the tropical rainforest are important pollinators. One study focused on the relationship between pollinators and Palicourea padifolia Rubiaceae which is a shrub in the understory of middle-elevation cloud forests.
This species exhibits distylous polymorphism some having long styles and short stamens and others have the reverse and is self-incompatible individual plants are unable to self pollinate. For questions regarding this web site, contact Webmaster Plant-Plant Relationships Many interesting plant to plant relationships exist, covering the spectrum from mutually beneficial to wholly parasitic. An example of a beneficial, plant-plant relationship familiar to many gardeners is the "Three Sisters Garden.
Biodiversity in agricultural landscapes: The effect of apple cultivar on epiphyte diversity
The corn plants grew straight and tall, giving the pole beans something to climb on. The beans, since they are legumes, contributed nitrogen to the soil. And the pumpkins shaded out competing weeds. And even something as simple as the relationship of a tree to the groundcover beneath it can be considered a beneficial, plant-plant relationship.
The tree casts shade, providing habitat for a shade-loving groundcover, and the groundcover in turn keeps more deep-rooted and competitive grasses at bay. One interesting group of plants are the epiphytes.
Water is the most pressing issue concerning immediate plant survival. The tropics, though generally more moist than temperate regions, often experience periods of drought so epiphytes have used several strategies of surviving between rainy seasons. Succulence, or the development of specialized storage organs, is a common strategy. Christmas cactus, orchid cactus, many epiphytic gesneriads and peperomias have succulent stems or leaves that see them through dry periods.
Resurrection fern, a common fern found on tree trunks in the southern half of Arkansas, shrivels up and appears to be dead but quickly revives when moisture returns. Orchids such as catleyas or oncidiums have developed swollen stem bases called pseudobulbs that swell during periods of abundant moisture and shrivel during dry spells. Most epiphytic orchids also have large stringy roots that affix the plant to the tree trunk but also aid in absorbing water directly from humid air.
These soda-straw size aerial roots are silver-grey in color due to a coating of valamen which consists of spongy, dead cells that efficiently pull water directly from the air when the relative humidity is above 50 percent. Bromeliads often employ a whorl of leaves arranged like a living funnel that catches and stores water in their so-called tank.
This water not only gets the plants through periods of drought but provides habitat for a miniature ecosystem that includes a complex array of codependent organisms.